Merge pull request #24 from Aquaveo/migration-fix

Fix for Issue #23

.gitignore

@@ -1,4 +1,5 @@
 .idea
+example/venv
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]

CHANGELOG.md

@@ -0,0 +1,35 @@
+# Change Log
+
+## 2.0
+  * Dropped support to djangp-1.8 and Python 2.7
+  * Added: never-cache decorator
+  * Fixes to Make Email Method More Robust 
+  * Addresses several structure and style issues with TOTP and Email dialogs
+  * Updated to fido2 0.8.1
+    
+Thanks to @swainn
+
+## v1.9.1
+   * Fixed: is_authenticated #13
+   * Fixed: is_anonymous #6
+    
+    thanks to @d3cline,  
+
+## v1.7
+  * Better Error Management
+  * Better Token recheck
+## v 1.6.0
+  * Fixed some issues for django>= 2.0
+  * Added example app.
+
+## v.1.5.0
+  * Added id the key used to validate to the session dictionary as 'id'
+## v1.4.0
+  * Updated to FIDO == 0.7
+
+## v1.3.0
+  * Updated to FIDO2 == 0.6
+  * Windows Hello is now supported.
+
+## v1.2.0
+ * Added:  MFA_HIDE_DISABLE setting option to disable users from deactivating their keys.

EXAMPLE.md

@@ -0,0 +1,8 @@
+# Use of Example project
+
+1. create virtual env
+`virtualenv venv`
+1. activate env `source venv/bin/activate`
+1. install requirements `pip install -r requirements.txt`
+1. migrate `python manage.py migrate`
+1. create super user 'python manage.py createsuperuser' 

README.md

@@ -7,9 +7,14 @@ Web Authencation API (WebAuthn) is state-of-the art techology that is expected t
 
 ![Andriod Fingerprint](https://cdn-images-1.medium.com/max/800/1*1FWkRE8D7NTA2Kn1DrPjPA.png)
 
-For FIDO2, **security keys**, **Apple's Touch ID (Chrome)** and **android-safetynet** are supported.
+For FIDO2, the following are supported
+ * **security keys** (Firefox 60+, Chrome 67+, Edge 18+, Safari 13 on Mac OS, Chrome on Andriod, Safari on iOS 13.3+),
+ * **Windows Hello** (Firefox 67+, Chrome 72+ , Edge) ,
+ * **Apple's Touch ID** (Chrome 70+ on Mac OS X ),
+ * **android-safetynet** (Chrome 70+, Firefox 68+)
+ * **NFC devices using PCSC** (Not Tested, but as supported in fido2)
 
-In English :), It allows you to verify the user by security keys on PC, Laptops, Touch ID on Macboks (Chrome) and Fingerprint/PIN on Andriod Phones.
+In English :), It allows you to verify the user by security keys on PC, Laptops or Mobiles, Windows Hello (Fingerprint, PIN) on Windows 10 Build 1903+ (May 2019 Update) Touch ID on Macbooks (Chrome) and Fingerprint/Face/Iris/PIN on Andriod Phones.
 
 Trusted device is a mode for the user to add a device that doesn't support security keys like iOS and andriod without fingerprints or NFC.
 
@@ -24,7 +29,7 @@ Depends on
 * ua-parser
 * user-agents
 * python-jose
-* fido2==0.5
+* fido2==0.7
 
 
 # Installation
@@ -36,6 +41,8 @@ Depends on
    'mfa',
    '......')
    ```
+1. Collect Static Files
+`python manage.py collectstatic`
 1. Add the following settings to your file
 
    ```python 
@@ -45,6 +52,8 @@ Depends on
    MFA_RECHECK_MIN=10         # Minimum interval in seconds
    MFA_RECHECK_MAX=30         # Maximum in seconds
    MFA_QUICKLOGIN=True        # Allow quick login for returning users by provide only their 2FA
+   MFA_HIDE_DISABLE=('FIDO2',)     # Can the user disable his key (Added in 1.2.0).
+   MFA_OWNED_BY_ENTERPRISE = FALSE  # Who owns security keys   
 
    TOKEN_ISSUER_NAME="PROJECT_NAME"      #TOTP Issuer name
 
@@ -60,8 +69,9 @@ Depends on
    * Trusted_Devices
    * Email
    
-   **Note**: Starting version 1.1, ~~FIDO_LOGIN_URL~~ isn't required for FIDO2 anymore.
+   **Notes**:
-   
+    * Starting version 1.1, ~~FIDO_LOGIN_URL~~ isn't required for FIDO2 anymore.
+    * Starting version 1.7.0, Key owners can be specified.
 1. Break your login function
 
    Usually your login function will check for username and password, log the user in if the username and password are correct and create the user session, to support mfa, this has to change
@@ -142,3 +152,9 @@ function some_func() {
   }
 
 ````
+
+# Contributors
+* [mahmoodnasr](https://github.com/mahmoodnasr)
+* [d3cline](https://github.com/d3cline)
+* [swainn](https://github.com/swainn)
+* [unramk](https://github.com/unramk)

example/example/auth.py

@@ -0,0 +1,30 @@
+from django.shortcuts import render
+from django.http import HttpResponseRedirect
+from django.urls import reverse
+from django.contrib.auth import authenticate,login,logout
+from django.contrib.auth.models import User
+def loginView(request):
+    context={}
+    if request.method=="POST":
+        username=request.POST["username"]
+        password=request.POST["password"]
+        user=authenticate(username=username,password=password)
+        if user:
+            from mfa.helpers import has_mfa
+            res = has_mfa(username = username, request = request)  # has_mfa returns false or HttpResponseRedirect
+            if res:
+                return res
+            return create_session(request,user.username)
+        context["invalid"]=True
+    return render(request, "login.html", context)
+
+def create_session(request,username):
+    user=User.objects.get(username=username)
+    user.backend='django.contrib.auth.backends.ModelBackend'
+    login(request, user)
+    return HttpResponseRedirect(reverse('home'))
+
+
+def logoutView(request):
+    logout(request)
+    return  render(request,"logout.html",{})

example/example/settings.py

@@ -0,0 +1,148 @@
+"""
+Django settings for example project.
+
+Generated by 'django-admin startproject' using Django 2.0.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/2.0/topics/settings/
+
+For the full list of settings and their values, see
+https://docs.djangoproject.com/en/2.0/ref/settings/
+"""
+
+import os
+
+# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
+BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+
+# Quick-start development settings - unsuitable for production
+# See https://docs.djangoproject.com/en/2.0/howto/deployment/checklist/
+
+# SECURITY WARNING: keep the secret key used in production secret!
+SECRET_KEY = '#9)q!_i3@pr-^3oda(e^3$x!kq3b4f33#5l@+=+&vuz+p6gb3g'
+
+# SECURITY WARNING: don't run with debug turned on in production!
+DEBUG = True
+
+ALLOWED_HOSTS = []
+
+
+# Application definition
+
+INSTALLED_APPS = [
+    'django.contrib.admin',
+    'django.contrib.auth',
+    'django.contrib.contenttypes',
+    'django.contrib.sessions',
+    'django.contrib.messages',
+    'django.contrib.staticfiles',
+    'mfa',
+    'sslserver'
+]
+
+MIDDLEWARE = [
+    'django.middleware.security.SecurityMiddleware',
+    'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
+    'django.middleware.csrf.CsrfViewMiddleware',
+    'django.contrib.auth.middleware.AuthenticationMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
+]
+
+ROOT_URLCONF = 'example.urls'
+
+TEMPLATES = [
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [os.path.join(BASE_DIR ,'example','templates' )],
+        'APP_DIRS': True,
+        'OPTIONS': {
+            'context_processors': [
+                'django.template.context_processors.debug',
+                'django.template.context_processors.request',
+                'django.contrib.auth.context_processors.auth',
+                'django.contrib.messages.context_processors.messages',
+            ],
+        },
+    },
+]
+
+WSGI_APPLICATION = 'example.wsgi.application'
+
+
+# Database
+# https://docs.djangoproject.com/en/2.0/ref/settings/#databases
+
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
+    }
+}
+
+
+# Password validation
+# https://docs.djangoproject.com/en/2.0/ref/settings/#auth-password-validators
+
+AUTH_PASSWORD_VALIDATORS = [
+    {
+        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
+    },
+]
+
+
+# Internationalization
+# https://docs.djangoproject.com/en/2.0/topics/i18n/
+
+LANGUAGE_CODE = 'en-us'
+
+TIME_ZONE = 'UTC'
+
+USE_I18N = True
+
+USE_L10N = True
+
+USE_TZ = True
+
+
+# Static files (CSS, JavaScript, Images)
+# https://docs.djangoproject.com/en/2.0/howto/static-files/
+
+STATIC_URL = '/static/'
+#STATIC_ROOT=(os.path.join(BASE_DIR,'static'))
+STATICFILES_DIRS=[os.path.join(BASE_DIR,'static')]
+LOGIN_URL="/auth/login"
+
+EMAIL_FROM='Test App'
+EMAIL_HOST="smtp.gmail.com"
+EMAIL_PORT=587
+EMAIL_HOST_USER=""
+EMAIL_HOST_PASSWORD=''
+EMAIL_USE_TLS=True
+
+
+
+MFA_UNALLOWED_METHODS=()   # Methods that shouldn't be allowed for the user
+MFA_LOGIN_CALLBACK="example.auth.create_session"      # A function that should be called by username to login the user in session
+MFA_RECHECK=True           # Allow random rechecking of the user
+MFA_RECHECK_MIN=10         # Minimum interval in seconds
+MFA_RECHECK_MAX=30         # Maximum in seconds
+MFA_QUICKLOGIN=True        # Allow quick login for returning users by provide only their 2FA
+MFA_HIDE_DISABLE=('FIDO2',)     # Can the user disable his key (Added in 1.2.0).
+
+TOKEN_ISSUER_NAME="PROJECT_NAME"      #TOTP Issuer name
+
+U2F_APPID="https://localhost"    #URL For U2F
+FIDO_SERVER_ID=u"localhost"      # Server rp id for FIDO2, it the full domain of your project
+FIDO_SERVER_NAME=u"PROJECT_NAME"

example/example/templates/base.html

@@ -0,0 +1,156 @@
+{% load static %}
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+
+  <meta charset="utf-8">
+  <meta http-equiv="X-UA-Compatible" content="IE=edge">
+  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
+  <meta name="description" content="">
+  <meta name="author" content="">
+
+  <title>SB Admin - Blank Page</title>
+
+  <!-- Custom fonts for this template-->
+  <link href="{% static 'vendor/fontawesome-free/css/all.min.css'%}" rel="stylesheet" type="text/css">
+
+  <!-- Page level plugin CSS-->
+  <link href="{% static 'vendor/datatables/dataTables.bootstrap4.css'%}" rel="stylesheet">
+
+  <!-- Custom styles for this template-->
+  <link href="{% static 'css/sb-admin.css'%}" rel="stylesheet">
+    <script src="{% static 'vendor/jquery/jquery.min.js'%}"></script>
+
+</head>
+
+<body id="page-top">
+
+  <nav class="navbar navbar-expand navbar-dark bg-dark static-top">
+      <button class="btn btn-link btn-sm text-white order-1 order-sm-0" id="sidebarToggle" href="#">
+      <i class="fas fa-bars"></i>
+    </button>
+    <a class="navbar-brand mr-1" href="index.html">Django-mfa2</a>
+
+
+
+    <!-- Navbar Search -->
+    <form class="d-none d-md-inline-block form-inline ml-auto mr-0 mr-md-3 my-2 my-md-0">
+      <div class="input-group">
+        <input type="text" class="form-control" placeholder="Search for..." aria-label="Search" aria-describedby="basic-addon2">
+        <div class="input-group-append">
+          <button class="btn btn-primary" type="button">
+            <i class="fas fa-search"></i>
+          </button>
+        </div>
+      </div>
+    </form>
+
+    <!-- Navbar -->
+    <ul class="navbar-nav ml-auto ml-md-0">
+      <li class="nav-item dropdown no-arrow mx-1">
+        <a class="nav-link dropdown-toggle" href="#" id="alertsDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+          <i class="fas fa-bell fa-fw"></i>
+          <span class="badge badge-danger"></span>
+        </a>
+        <div class="dropdown-menu dropdown-menu-right" aria-labelledby="alertsDropdown">
+          <a class="dropdown-item" href="#">Action</a>
+          <a class="dropdown-item" href="#">Another action</a>
+          <div class="dropdown-divider"></div>
+          <a class="dropdown-item" href="#">Something else here</a>
+        </div>
+      </li>
+
+      <li class="nav-item dropdown no-arrow">
+        <a class="nav-link dropdown-toggle" href="#" id="userDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+          <i class="fas fa-user-circle fa-fw"></i>&nbsp;{{ request.user.username }}
+        </a>
+        <div class="dropdown-menu dropdown-menu-right" aria-labelledby="userDropdown">
+          <a class="dropdown-item" href="#">Settings</a>
+          <a class="dropdown-item" href="{% url 'mfa_home' %}">Security</a>
+          <a class="dropdown-item" href="#">Activity Log</a>
+          <div class="dropdown-divider"></div>
+          <a class="dropdown-item" href="#" data-toggle="modal" data-target="#logoutModal">Logout</a>
+        </div>
+
+      </li>
+    </ul>
+
+  </nav>
+
+  <div id="wrapper">
+
+    <!-- Sidebar -->
+    <ul class="sidebar navbar-nav">
+      <li class="nav-item">
+        <a class="nav-link" href="index.html">
+          <i class="fas fa-fw fa-tachometer-alt"></i>
+          <span>Dashboard</span>
+        </a>
+      </li>
+
+    </ul>
+
+    <div id="content-wrapper">
+
+      <div class="container-fluid">
+
+        <!-- Breadcrumbs-->
+        {% block content %}
+        {% endblock %}
+
+      </div>
+      <!-- /.container-fluid -->
+
+      <!-- Sticky Footer -->
+      <footer class="sticky-footer">
+        <div class="container my-auto">
+          <div class="copyright text-center my-auto">
+            <span>Copyright © Your Website 2019</span>
+          </div>
+        </div>
+      </footer>
+
+    </div>
+    <!-- /.content-wrapper -->
+
+  </div>
+  <!-- /#wrapper -->
+
+  <!-- Scroll to Top Button-->
+  <a class="scroll-to-top rounded" href="#page-top">
+    <i class="fas fa-angle-up"></i>
+  </a>
+
+  <!-- Logout Modal-->
+  <div class="modal fade" id="logoutModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
+    <div class="modal-dialog" role="document">
+      <div class="modal-content">
+        <div class="modal-header">
+          <h5 class="modal-title" id="exampleModalLabel">Ready to Leave?</h5>
+          <button class="close" type="button" data-dismiss="modal" aria-label="Close">
+            <span aria-hidden="true">×</span>
+          </button>
+        </div>
+        <div class="modal-body">Select "Logout" below if you are ready to end your current session.</div>
+        <div class="modal-footer">
+          <button class="btn btn-secondary" type="button" data-dismiss="modal">Cancel</button>
+          <a class="btn btn-primary" href="{% url 'logout' %}">Logout</a>
+        </div>
+      </div>
+    </div>
+  </div>
+
+  <!-- Bootstrap core JavaScript-->
+  <script src="{% static 'vendor/bootstrap/js/bootstrap.bundle.min.js'%}"></script>
+
+  <!-- Core plugin JavaScript-->
+  <script src="{%static 'vendor/jquery-easing/jquery.easing.min.js'%}"></script>
+
+  <!-- Custom scripts for all pages-->
+  <script src="{% static 'js/sb-admin.min.js'%}"></script>
+    {% block head %}
+    {% endblock %}
+</body>
+
+</html>

example/example/templates/blank.html

@@ -0,0 +1,197 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+
+  <meta charset="utf-8">
+  <meta http-equiv="X-UA-Compatible" content="IE=edge">
+  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
+  <meta name="description" content="">
+  <meta name="author" content="">
+
+  <title>SB Admin - Blank Page</title>
+
+  <!-- Custom fonts for this template-->
+  <link href="vendor/fontawesome-free/css/all.min.css" rel="stylesheet" type="text/css">
+
+  <!-- Page level plugin CSS-->
+  <link href="vendor/datatables/dataTables.bootstrap4.css" rel="stylesheet">
+
+  <!-- Custom styles for this template-->
+  <link href="css/sb-admin.css" rel="stylesheet">
+
+</head>
+
+<body id="page-top">
+
+  <nav class="navbar navbar-expand navbar-dark bg-dark static-top">
+
+    <a class="navbar-brand mr-1" href="index.html">Start Bootstrap</a>
+
+    <button class="btn btn-link btn-sm text-white order-1 order-sm-0" id="sidebarToggle" href="#">
+      <i class="fas fa-bars"></i>
+    </button>
+
+    <!-- Navbar Search -->
+    <form class="d-none d-md-inline-block form-inline ml-auto mr-0 mr-md-3 my-2 my-md-0">
+      <div class="input-group">
+        <input type="text" class="form-control" placeholder="Search for..." aria-label="Search" aria-describedby="basic-addon2">
+        <div class="input-group-append">
+          <button class="btn btn-primary" type="button">
+            <i class="fas fa-search"></i>
+          </button>
+        </div>
+      </div>
+    </form>
+
+    <!-- Navbar -->
+    <ul class="navbar-nav ml-auto ml-md-0">
+      <li class="nav-item dropdown no-arrow mx-1">
+        <a class="nav-link dropdown-toggle" href="#" id="alertsDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+          <i class="fas fa-bell fa-fw"></i>
+          <span class="badge badge-danger">9+</span>
+        </a>
+        <div class="dropdown-menu dropdown-menu-right" aria-labelledby="alertsDropdown">
+          <a class="dropdown-item" href="#">Action</a>
+          <a class="dropdown-item" href="#">Another action</a>
+          <div class="dropdown-divider"></div>
+          <a class="dropdown-item" href="#">Something else here</a>
+        </div>
+      </li>
+      <li class="nav-item dropdown no-arrow mx-1">
+        <a class="nav-link dropdown-toggle" href="#" id="messagesDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+          <i class="fas fa-envelope fa-fw"></i>
+          <span class="badge badge-danger">7</span>
+        </a>
+        <div class="dropdown-menu dropdown-menu-right" aria-labelledby="messagesDropdown">
+          <a class="dropdown-item" href="#">Action</a>
+          <a class="dropdown-item" href="#">Another action</a>
+          <div class="dropdown-divider"></div>
+          <a class="dropdown-item" href="#">Something else here</a>
+        </div>
+      </li>
+      <li class="nav-item dropdown no-arrow">
+        <a class="nav-link dropdown-toggle" href="#" id="userDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+          <i class="fas fa-user-circle fa-fw"></i>
+        </a>
+        <div class="dropdown-menu dropdown-menu-right" aria-labelledby="userDropdown">
+          <a class="dropdown-item" href="#">Settings</a>
+          <a class="dropdown-item" href="#">Activity Log</a>
+          <div class="dropdown-divider"></div>
+          <a class="dropdown-item" href="#" data-toggle="modal" data-target="#logoutModal">Logout</a>
+        </div>
+      </li>
+    </ul>
+
+  </nav>
+
+  <div id="wrapper">
+
+    <!-- Sidebar -->
+    <ul class="sidebar navbar-nav">
+      <li class="nav-item">
+        <a class="nav-link" href="index.html">
+          <i class="fas fa-fw fa-tachometer-alt"></i>
+          <span>Dashboard</span>
+        </a>
+      </li>
+      <li class="nav-item dropdown">
+        <a class="nav-link dropdown-toggle" href="#" id="pagesDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+          <i class="fas fa-fw fa-folder"></i>
+          <span>Pages</span>
+        </a>
+        <div class="dropdown-menu" aria-labelledby="pagesDropdown">
+          <h6 class="dropdown-header">Login Screens:</h6>
+          <a class="dropdown-item" href="login.html">Login</a>
+          <a class="dropdown-item" href="register.html">Register</a>
+          <a class="dropdown-item" href="forgot-password.html">Forgot Password</a>
+          <div class="dropdown-divider"></div>
+          <h6 class="dropdown-header">Other Pages:</h6>
+          <a class="dropdown-item" href="404.html">404 Page</a>
+          <a class="dropdown-item active" href="blank.html">Blank Page</a>
+        </div>
+      </li>
+      <li class="nav-item">
+        <a class="nav-link" href="charts.html">
+          <i class="fas fa-fw fa-chart-area"></i>
+          <span>Charts</span></a>
+      </li>
+      <li class="nav-item">
+        <a class="nav-link" href="tables.html">
+          <i class="fas fa-fw fa-table"></i>
+          <span>Tables</span></a>
+      </li>
+    </ul>
+
+    <div id="content-wrapper">
+
+      <div class="container-fluid">
+
+        <!-- Breadcrumbs-->
+        <ol class="breadcrumb">
+          <li class="breadcrumb-item">
+            <a href="index.html">Dashboard</a>
+          </li>
+          <li class="breadcrumb-item active">Blank Page</li>
+        </ol>
+
+        <!-- Page Content -->
+        <h1>Blank Page</h1>
+        <hr>
+        <p>This is a great starting point for new custom pages.</p>
+
+      </div>
+      <!-- /.container-fluid -->
+
+      <!-- Sticky Footer -->
+      <footer class="sticky-footer">
+        <div class="container my-auto">
+          <div class="copyright text-center my-auto">
+            <span>Copyright © Your Website 2019</span>
+          </div>
+        </div>
+      </footer>
+
+    </div>
+    <!-- /.content-wrapper -->
+
+  </div>
+  <!-- /#wrapper -->
+
+  <!-- Scroll to Top Button-->
+  <a class="scroll-to-top rounded" href="#page-top">
+    <i class="fas fa-angle-up"></i>
+  </a>
+
+  <!-- Logout Modal-->
+  <div class="modal fade" id="logoutModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
+    <div class="modal-dialog" role="document">
+      <div class="modal-content">
+        <div class="modal-header">
+          <h5 class="modal-title" id="exampleModalLabel">Ready to Leave?</h5>
+          <button class="close" type="button" data-dismiss="modal" aria-label="Close">
+            <span aria-hidden="true">×</span>
+          </button>
+        </div>
+        <div class="modal-body">Select "Logout" below if you are ready to end your current session.</div>
+        <div class="modal-footer">
+          <button class="btn btn-secondary" type="button" data-dismiss="modal">Cancel</button>
+          <a class="btn btn-primary" href="login.html">Logout</a>
+        </div>
+      </div>
+    </div>
+  </div>
+
+  <!-- Bootstrap core JavaScript-->
+  <script src="vendor/jquery/jquery.min.js"></script>
+  <script src="vendor/bootstrap/js/bootstrap.bundle.min.js"></script>
+
+  <!-- Core plugin JavaScript-->
+  <script src="vendor/jquery-easing/jquery.easing.min.js"></script>
+
+  <!-- Custom scripts for all pages-->
+  <script src="js/sb-admin.min.js"></script>
+
+</body>
+
+</html>

example/example/templates/home.html

@@ -0,0 +1,19 @@
+{% extends 'base.html' %}
+{% load static %}
+{% block content %}
+      <div class="container-fluid">
+
+        <!-- Breadcrumbs-->
+        <ol class="breadcrumb">
+          <li class="breadcrumb-item">
+            <a href="index.html">Dashboard</a>
+          </li>
+          <li class="breadcrumb-item active">Blank Page</li>
+        </ol>
+
+        <!-- Page Content -->
+        <h1>Welcome {{ request.user.username }}!</h1>
+        <hr>
+
+      </div>
+      {% endblock %}

example/example/templates/login.html

@@ -0,0 +1,62 @@
+{% load static %}
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+
+  <meta charset="utf-8">
+  <meta http-equiv="X-UA-Compatible" content="IE=edge">
+  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
+  <meta name="description" content="">
+  <meta name="author" content="">
+
+  <title>Login</title>
+
+  <!-- Custom fonts for this template-->
+  <link href="{% static  'vendor/fontawesome-free/css/all.min.css'%}" rel="stylesheet" type="text/css">
+
+  <!-- Custom styles for this template-->
+  <link href="{% static 'css/sb-admin.css'%}" rel="stylesheet">
+
+</head>
+
+<body class="bg-dark">
+
+  <div class="container">
+    <div class="card card-login mx-auto mt-5">
+      <div class="card-header">Login</div>
+      <div class="card-body">
+          {% if invalid %}
+              <div class="alert alert-danger">Invalid Username or password</div>
+          {% endif %}
+        <form action="{% url 'login' %}" method="post">
+            {% csrf_token %}
+          <div class="form-group">
+            <div class="form-label-group">
+              <input type="text" id="inputUsername" name="username" class="form-control" placeholder="username" required="required" autofocus="autofocus">
+              <label for="inputUsername">Username</label>
+            </div>
+          </div>
+          <div class="form-group">
+            <div class="form-label-group">
+              <input type="password" id="inputPassword"  name="password" class="form-control" placeholder="Password" required="required">
+              <label for="inputPassword">Password</label>
+            </div>
+          </div>
+
+          <button class="btn btn-primary btn-block" type="submit">Login</button>
+        </form>
+      </div>
+    </div>
+  </div>
+
+  <!-- Bootstrap core JavaScript-->
+  <script src="{% static 'vendor/jquery/jquery.min.js'%}"></script>
+  <script src="{%static 'vendor/bootstrap/js/bootstrap.bundle.min.js'%}"></script>
+
+  <!-- Core plugin JavaScript-->
+  <script src="{% static 'vendor/jquery-easing/jquery.easing.min.js'%}"></script>
+
+</body>
+
+</html>

example/example/templates/logout.html

@@ -0,0 +1,43 @@
+{% load static %}
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+
+  <meta charset="utf-8">
+  <meta http-equiv="X-UA-Compatible" content="IE=edge">
+  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
+  <meta name="description" content="">
+  <meta name="author" content="">
+
+  <title>Login</title>
+
+  <!-- Custom fonts for this template-->
+  <link href="{% static  'vendor/fontawesome-free/css/all.min.css'%}" rel="stylesheet" type="text/css">
+
+  <!-- Custom styles for this template-->
+  <link href="{% static 'css/sb-admin.css'%}" rel="stylesheet">
+
+</head>
+
+<body class="bg-dark">
+
+  <div class="container">
+    <div class="card card-login mx-auto mt-5">
+      <div class="card-header">Logout</div>
+      <div class="card-body">
+        <p>You have logged out successfully, <a href="{% url 'login' %}">Login again</a> </p>
+      </div>
+    </div>
+  </div>
+
+  <!-- Bootstrap core JavaScript-->
+  <script src="{% static 'vendor/jquery/jquery.min.js'%}"></script>
+  <script src="{%static 'vendor/bootstrap/js/bootstrap.bundle.min.js'%}"></script>
+
+  <!-- Core plugin JavaScript-->
+  <script src="{% static 'vendor/jquery-easing/jquery.easing.min.js'%}"></script>
+
+</body>
+
+</html>

example/example/templates/mfa_auth_base.html

@@ -0,0 +1,45 @@
+{% load static %}
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+
+  <meta charset="utf-8">
+  <meta http-equiv="X-UA-Compatible" content="IE=edge">
+  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
+  <meta name="description" content="">
+  <meta name="author" content="">
+
+  <title>Login</title>
+
+  <!-- Custom fonts for this template-->
+  <link href="{% static  'vendor/fontawesome-free/css/all.min.css'%}" rel="stylesheet" type="text/css">
+
+  <!-- Custom styles for this template-->
+  <link href="{% static 'css/sb-admin.css'%}" rel="stylesheet">
+<script src="{% static 'vendor/jquery/jquery.min.js'%}"></script>
+
+</head>
+
+<body class="bg-dark">
+
+  <div class="container">
+   <div class="card card-login mx-auto mt-5">
+      <div class="card-header">Login</div>
+      <div class="card-body">
+    {% block content %}
+  {% endblock %}
+  </div>
+   </div>
+  </div>
+
+  <!-- Bootstrap core JavaScript-->
+  <script src="{%static 'vendor/bootstrap/js/bootstrap.bundle.min.js'%}"></script>
+
+  <!-- Core plugin JavaScript-->
+  <script src="{% static 'vendor/jquery-easing/jquery.easing.min.js'%}"></script>
+    {% block head %}
+    {% endblock %}
+</body>
+
+</html>

example/example/templates/mfa_email_token_template.html

@@ -0,0 +1,2 @@
+<p>Dear {{ user.username }}</p>
+Your OTP is: <b>{{ otp }}</b>

example/example/urls.py

@@ -0,0 +1,26 @@
+"""example URL Configuration
+
+The `urlpatterns` list routes URLs to views. For more information please see:
+    https://docs.djangoproject.com/en/2.0/topics/http/urls/
+Examples:
+Function views
+    1. Add an import:  from my_app import views
+    2. Add a URL to urlpatterns:  path('', views.home, name='home')
+Class-based views
+    1. Add an import:  from other_app.views import Home
+    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
+Including another URLconf
+    1. Import the include() function: from django.urls import include, path
+    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
+"""
+from django.contrib import admin
+from django.urls import path,re_path,include
+from . import views,auth
+urlpatterns = [
+    path('admin/', admin.site.urls),
+    path('mfa/', include('mfa.urls')),
+    path('auth/login',auth.loginView,name="login"),
+    path('auth/logout',auth.logoutView,name="logout"),
+
+    re_path('^$',views.home,name='home')
+]

example/example/views.py

@@ -0,0 +1,7 @@
+from django.shortcuts import render
+from django.contrib.auth.decorators import login_required
+
+
+@login_required()
+def home(request):
+    return render(request,"home.html",{})

example/example/wsgi.py

@@ -0,0 +1,16 @@
+"""
+WSGI config for example project.
+
+It exposes the WSGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/2.0/howto/deployment/wsgi/
+"""
+
+import os
+
+from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "example.settings")
+
+application = get_wsgi_application()

example/manage.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python
+import os
+import sys
+
+if __name__ == "__main__":
+    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "example.settings")
+    try:
+        from django.core.management import execute_from_command_line
+    except ImportError as exc:
+        raise ImportError(
+            "Couldn't import Django. Are you sure it's installed and "
+            "available on your PYTHONPATH environment variable? Did you "
+            "forget to activate a virtual environment?"
+        ) from exc
+    execute_from_command_line(sys.argv)

example/mfa

@@ -0,0 +1 @@
+../mfa/

example/requiremnts.txt

@@ -0,0 +1,2 @@
+django==2.0
+django-sslserver

example/static/js/demo/chart-area-demo.js

@@ -0,0 +1,54 @@
+// Set new default font family and font color to mimic Bootstrap's default styling
+Chart.defaults.global.defaultFontFamily = '-apple-system,system-ui,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif';
+Chart.defaults.global.defaultFontColor = '#292b2c';
+
+// Area Chart Example
+var ctx = document.getElementById("myAreaChart");
+var myLineChart = new Chart(ctx, {
+  type: 'line',
+  data: {
+    labels: ["Mar 1", "Mar 2", "Mar 3", "Mar 4", "Mar 5", "Mar 6", "Mar 7", "Mar 8", "Mar 9", "Mar 10", "Mar 11", "Mar 12", "Mar 13"],
+    datasets: [{
+      label: "Sessions",
+      lineTension: 0.3,
+      backgroundColor: "rgba(2,117,216,0.2)",
+      borderColor: "rgba(2,117,216,1)",
+      pointRadius: 5,
+      pointBackgroundColor: "rgba(2,117,216,1)",
+      pointBorderColor: "rgba(255,255,255,0.8)",
+      pointHoverRadius: 5,
+      pointHoverBackgroundColor: "rgba(2,117,216,1)",
+      pointHitRadius: 50,
+      pointBorderWidth: 2,
+      data: [10000, 30162, 26263, 18394, 18287, 28682, 31274, 33259, 25849, 24159, 32651, 31984, 38451],
+    }],
+  },
+  options: {
+    scales: {
+      xAxes: [{
+        time: {
+          unit: 'date'
+        },
+        gridLines: {
+          display: false
+        },
+        ticks: {
+          maxTicksLimit: 7
+        }
+      }],
+      yAxes: [{
+        ticks: {
+          min: 0,
+          max: 40000,
+          maxTicksLimit: 5
+        },
+        gridLines: {
+          color: "rgba(0, 0, 0, .125)",
+        }
+      }],
+    },
+    legend: {
+      display: false
+    }
+  }
+});

example/static/js/demo/chart-bar-demo.js

@@ -0,0 +1,46 @@
+// Set new default font family and font color to mimic Bootstrap's default styling
+Chart.defaults.global.defaultFontFamily = '-apple-system,system-ui,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif';
+Chart.defaults.global.defaultFontColor = '#292b2c';
+
+// Bar Chart Example
+var ctx = document.getElementById("myBarChart");
+var myLineChart = new Chart(ctx, {
+  type: 'bar',
+  data: {
+    labels: ["January", "February", "March", "April", "May", "June"],
+    datasets: [{
+      label: "Revenue",
+      backgroundColor: "rgba(2,117,216,1)",
+      borderColor: "rgba(2,117,216,1)",
+      data: [4215, 5312, 6251, 7841, 9821, 14984],
+    }],
+  },
+  options: {
+    scales: {
+      xAxes: [{
+        time: {
+          unit: 'month'
+        },
+        gridLines: {
+          display: false
+        },
+        ticks: {
+          maxTicksLimit: 6
+        }
+      }],
+      yAxes: [{
+        ticks: {
+          min: 0,
+          max: 15000,
+          maxTicksLimit: 5
+        },
+        gridLines: {
+          display: true
+        }
+      }],
+    },
+    legend: {
+      display: false
+    }
+  }
+});

example/static/js/demo/chart-pie-demo.js

@@ -0,0 +1,16 @@
+// Set new default font family and font color to mimic Bootstrap's default styling
+Chart.defaults.global.defaultFontFamily = '-apple-system,system-ui,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif';
+Chart.defaults.global.defaultFontColor = '#292b2c';
+
+// Pie Chart Example
+var ctx = document.getElementById("myPieChart");
+var myPieChart = new Chart(ctx, {
+  type: 'pie',
+  data: {
+    labels: ["Blue", "Red", "Yellow", "Green"],
+    datasets: [{
+      data: [12.21, 15.58, 11.25, 8.32],
+      backgroundColor: ['#007bff', '#dc3545', '#ffc107', '#28a745'],
+    }],
+  },
+});

example/static/js/demo/datatables-demo.js

@@ -0,0 +1,4 @@
+// Call the dataTables jQuery plugin
+$(document).ready(function() {
+  $('#dataTable').DataTable();
+});

example/static/js/sb-admin.js

@@ -0,0 +1,40 @@
+(function($) {
+  "use strict"; // Start of use strict
+
+  // Toggle the side navigation
+  $("#sidebarToggle").on('click', function(e) {
+    e.preventDefault();
+    $("body").toggleClass("sidebar-toggled");
+    $(".sidebar").toggleClass("toggled");
+  });
+
+  // Prevent the content wrapper from scrolling when the fixed side navigation hovered over
+  $('body.fixed-nav .sidebar').on('mousewheel DOMMouseScroll wheel', function(e) {
+    if ($(window).width() > 768) {
+      var e0 = e.originalEvent,
+        delta = e0.wheelDelta || -e0.detail;
+      this.scrollTop += (delta < 0 ? 1 : -1) * 30;
+      e.preventDefault();
+    }
+  });
+
+  // Scroll to top button appear
+  $(document).on('scroll', function() {
+    var scrollDistance = $(this).scrollTop();
+    if (scrollDistance > 100) {
+      $('.scroll-to-top').fadeIn();
+    } else {
+      $('.scroll-to-top').fadeOut();
+    }
+  });
+
+  // Smooth scrolling using jQuery easing
+  $(document).on('click', 'a.scroll-to-top', function(event) {
+    var $anchor = $(this);
+    $('html, body').stop().animate({
+      scrollTop: ($($anchor.attr('href')).offset().top)
+    }, 1000, 'easeInOutExpo');
+    event.preventDefault();
+  });
+
+})(jQuery); // End of use strict

example/static/js/sb-admin.min.js

@@ -0,0 +1,7 @@
+/*!
+ * Start Bootstrap - SB Admin v5.1.1 (https://startbootstrap.com/template-overviews/sb-admin)
+ * Copyright 2013-2019 Start Bootstrap
+ * Licensed under MIT (https://github.com/BlackrockDigital/startbootstrap-sb-admin/blob/master/LICENSE)
+ */
+
+!function(l){"use strict";l("#sidebarToggle").on("click",function(o){o.preventDefault(),l("body").toggleClass("sidebar-toggled"),l(".sidebar").toggleClass("toggled")}),l("body.fixed-nav .sidebar").on("mousewheel DOMMouseScroll wheel",function(o){if(768<l(window).width()){var e=o.originalEvent,t=e.wheelDelta||-e.detail;this.scrollTop+=30*(t<0?1:-1),o.preventDefault()}}),l(document).on("scroll",function(){100<l(this).scrollTop()?l(".scroll-to-top").fadeIn():l(".scroll-to-top").fadeOut()}),l(document).on("click","a.scroll-to-top",function(o){var e=l(this);l("html, body").stop().animate({scrollTop:l(e.attr("href")).offset().top},1e3,"easeInOutExpo"),o.preventDefault()})}(jQuery);

example/static/mfa/css/bootstrap-toggle.min.css

@@ -0,0 +1,28 @@
+/*! ========================================================================
+ * Bootstrap Toggle: bootstrap-toggle.css v2.2.0
+ * http://www.bootstraptoggle.com
+ * ========================================================================
+ * Copyright 2014 Min Hur, The New York Times Company
+ * Licensed under MIT
+ * ======================================================================== */
+.checkbox label .toggle,.checkbox-inline .toggle{margin-left:-20px;margin-right:5px}
+.toggle{position:relative;overflow:hidden}
+.toggle input[type=checkbox]{display:none}
+.toggle-group{position:absolute;width:200%;top:0;bottom:0;left:0;transition:left .35s;-webkit-transition:left .35s;-moz-user-select:none;-webkit-user-select:none}
+.toggle.off .toggle-group{left:-100%}
+.toggle-on{position:absolute;top:0;bottom:0;left:0;right:50%;margin:0;border:0;border-radius:0}
+.toggle-off{position:absolute;top:0;bottom:0;left:50%;right:0;margin:0;border:0;border-radius:0}
+.toggle-handle{position:relative;margin:0 auto;padding-top:0;padding-bottom:0;height:100%;width:0;border-width:0 1px}
+.toggle.btn{min-width:59px;min-height:34px}
+.toggle-on.btn{padding-right:24px}
+.toggle-off.btn{padding-left:24px}
+.toggle.btn-lg{min-width:79px;min-height:45px}
+.toggle-on.btn-lg{padding-right:31px}
+.toggle-off.btn-lg{padding-left:31px}
+.toggle-handle.btn-lg{width:40px}
+.toggle.btn-sm{min-width:50px;min-height:30px}
+.toggle-on.btn-sm{padding-right:20px}
+.toggle-off.btn-sm{padding-left:20px}
+.toggle.btn-xs{min-width:35px;min-height:22px}
+.toggle-on.btn-xs{padding-right:12px}
+.toggle-off.btn-xs{padding-left:12px}

example/static/mfa/js/bootstrap-toggle.min.js

@@ -0,0 +1,9 @@
+/*! ========================================================================
+ * Bootstrap Toggle: bootstrap-toggle.js v2.2.0
+ * http://www.bootstraptoggle.com
+ * ========================================================================
+ * Copyright 2014 Min Hur, The New York Times Company
+ * Licensed under MIT
+ * ======================================================================== */
++function(a){"use strict";function b(b){return this.each(function(){var d=a(this),e=d.data("bs.toggle"),f="object"==typeof b&&b;e||d.data("bs.toggle",e=new c(this,f)),"string"==typeof b&&e[b]&&e[b]()})}var c=function(b,c){this.$element=a(b),this.options=a.extend({},this.defaults(),c),this.render()};c.VERSION="2.2.0",c.DEFAULTS={on:"On",off:"Off",onstyle:"primary",offstyle:"default",size:"normal",style:"",width:null,height:null},c.prototype.defaults=function(){return{on:this.$element.attr("data-on")||c.DEFAULTS.on,off:this.$element.attr("data-off")||c.DEFAULTS.off,onstyle:this.$element.attr("data-onstyle")||c.DEFAULTS.onstyle,offstyle:this.$element.attr("data-offstyle")||c.DEFAULTS.offstyle,size:this.$element.attr("data-size")||c.DEFAULTS.size,style:this.$element.attr("data-style")||c.DEFAULTS.style,width:this.$element.attr("data-width")||c.DEFAULTS.width,height:this.$element.attr("data-height")||c.DEFAULTS.height}},c.prototype.render=function(){this._onstyle="btn-"+this.options.onstyle,this._offstyle="btn-"+this.options.offstyle;var b="large"===this.options.size?"btn-lg":"small"===this.options.size?"btn-sm":"mini"===this.options.size?"btn-xs":"",c=a('<label class="btn">').html(this.options.on).addClass(this._onstyle+" "+b),d=a('<label class="btn">').html(this.options.off).addClass(this._offstyle+" "+b+" active"),e=a('<span class="toggle-handle btn btn-default">').addClass(b),f=a('<div class="toggle-group">').append(c,d,e),g=a('<div class="toggle btn" data-toggle="toggle">').addClass(this.$element.prop("checked")?this._onstyle:this._offstyle+" off").addClass(b).addClass(this.options.style);this.$element.wrap(g),a.extend(this,{$toggle:this.$element.parent(),$toggleOn:c,$toggleOff:d,$toggleGroup:f}),this.$toggle.append(f);var h=this.options.width||Math.max(c.outerWidth(),d.outerWidth())+e.outerWidth()/2,i=this.options.height||Math.max(c.outerHeight(),d.outerHeight());c.addClass("toggle-on"),d.addClass("toggle-off"),this.$toggle.css({width:h,height:i}),this.options.height&&(c.css("line-height",c.height()+"px"),d.css("line-height",d.height()+"px")),this.update(!0),this.trigger(!0)},c.prototype.toggle=function(){this.$element.prop("checked")?this.off():this.on()},c.prototype.on=function(a){return this.$element.prop("disabled")?!1:(this.$toggle.removeClass(this._offstyle+" off").addClass(this._onstyle),this.$element.prop("checked",!0),void(a||this.trigger()))},c.prototype.off=function(a){return this.$element.prop("disabled")?!1:(this.$toggle.removeClass(this._onstyle).addClass(this._offstyle+" off"),this.$element.prop("checked",!1),void(a||this.trigger()))},c.prototype.enable=function(){this.$toggle.removeAttr("disabled"),this.$element.prop("disabled",!1)},c.prototype.disable=function(){this.$toggle.attr("disabled","disabled"),this.$element.prop("disabled",!0)},c.prototype.update=function(a){this.$element.prop("disabled")?this.disable():this.enable(),this.$element.prop("checked")?this.on(a):this.off(a)},c.prototype.trigger=function(b){this.$element.off("change.bs.toggle"),b||this.$element.change(),this.$element.on("change.bs.toggle",a.proxy(function(){this.update()},this))},c.prototype.destroy=function(){this.$element.off("change.bs.toggle"),this.$toggleGroup.remove(),this.$element.removeData("bs.toggle"),this.$element.unwrap()};var d=a.fn.bootstrapToggle;a.fn.bootstrapToggle=b,a.fn.bootstrapToggle.Constructor=c,a.fn.toggle.noConflict=function(){return a.fn.bootstrapToggle=d,this},a(function(){a("input[type=checkbox][data-toggle^=toggle]").bootstrapToggle()}),a(document).on("click.bs.toggle","div[data-toggle^=toggle]",function(b){var c=a(this).find("input[type=checkbox]");c.bootstrapToggle("toggle"),b.preventDefault()})}(jQuery);
+//# sourceMappingURL=bootstrap-toggle.min.js.map

example/static/mfa/js/cbor.js

@@ -0,0 +1,406 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014-2016 Patrick Gansterer <paroga@paroga.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+(function(global, undefined) { "use strict";
+var POW_2_24 = 5.960464477539063e-8,
+    POW_2_32 = 4294967296,
+    POW_2_53 = 9007199254740992;
+
+function encode(value) {
+  var data = new ArrayBuffer(256);
+  var dataView = new DataView(data);
+  var lastLength;
+  var offset = 0;
+
+  function prepareWrite(length) {
+    var newByteLength = data.byteLength;
+    var requiredLength = offset + length;
+    while (newByteLength < requiredLength)
+      newByteLength <<= 1;
+    if (newByteLength !== data.byteLength) {
+      var oldDataView = dataView;
+      data = new ArrayBuffer(newByteLength);
+      dataView = new DataView(data);
+      var uint32count = (offset + 3) >> 2;
+      for (var i = 0; i < uint32count; ++i)
+        dataView.setUint32(i << 2, oldDataView.getUint32(i << 2));
+    }
+
+    lastLength = length;
+    return dataView;
+  }
+  function commitWrite() {
+    offset += lastLength;
+  }
+  function writeFloat64(value) {
+    commitWrite(prepareWrite(8).setFloat64(offset, value));
+  }
+  function writeUint8(value) {
+    commitWrite(prepareWrite(1).setUint8(offset, value));
+  }
+  function writeUint8Array(value) {
+    var dataView = prepareWrite(value.length);
+    for (var i = 0; i < value.length; ++i)
+      dataView.setUint8(offset + i, value[i]);
+    commitWrite();
+  }
+  function writeUint16(value) {
+    commitWrite(prepareWrite(2).setUint16(offset, value));
+  }
+  function writeUint32(value) {
+    commitWrite(prepareWrite(4).setUint32(offset, value));
+  }
+  function writeUint64(value) {
+    var low = value % POW_2_32;
+    var high = (value - low) / POW_2_32;
+    var dataView = prepareWrite(8);
+    dataView.setUint32(offset, high);
+    dataView.setUint32(offset + 4, low);
+    commitWrite();
+  }
+  function writeTypeAndLength(type, length) {
+    if (length < 24) {
+      writeUint8(type << 5 | length);
+    } else if (length < 0x100) {
+      writeUint8(type << 5 | 24);
+      writeUint8(length);
+    } else if (length < 0x10000) {
+      writeUint8(type << 5 | 25);
+      writeUint16(length);
+    } else if (length < 0x100000000) {
+      writeUint8(type << 5 | 26);
+      writeUint32(length);
+    } else {
+      writeUint8(type << 5 | 27);
+      writeUint64(length);
+    }
+  }
+
+  function encodeItem(value) {
+    var i;
+
+    if (value === false)
+      return writeUint8(0xf4);
+    if (value === true)
+      return writeUint8(0xf5);
+    if (value === null)
+      return writeUint8(0xf6);
+    if (value === undefined)
+      return writeUint8(0xf7);
+
+    switch (typeof value) {
+      case "number":
+        if (Math.floor(value) === value) {
+          if (0 <= value && value <= POW_2_53)
+            return writeTypeAndLength(0, value);
+          if (-POW_2_53 <= value && value < 0)
+            return writeTypeAndLength(1, -(value + 1));
+        }
+        writeUint8(0xfb);
+        return writeFloat64(value);
+
+      case "string":
+        var utf8data = [];
+        for (i = 0; i < value.length; ++i) {
+          var charCode = value.charCodeAt(i);
+          if (charCode < 0x80) {
+            utf8data.push(charCode);
+          } else if (charCode < 0x800) {
+            utf8data.push(0xc0 | charCode >> 6);
+            utf8data.push(0x80 | charCode & 0x3f);
+          } else if (charCode < 0xd800) {
+            utf8data.push(0xe0 | charCode >> 12);
+            utf8data.push(0x80 | (charCode >> 6)  & 0x3f);
+            utf8data.push(0x80 | charCode & 0x3f);
+          } else {
+            charCode = (charCode & 0x3ff) << 10;
+            charCode |= value.charCodeAt(++i) & 0x3ff;
+            charCode += 0x10000;
+
+            utf8data.push(0xf0 | charCode >> 18);
+            utf8data.push(0x80 | (charCode >> 12)  & 0x3f);
+            utf8data.push(0x80 | (charCode >> 6)  & 0x3f);
+            utf8data.push(0x80 | charCode & 0x3f);
+          }
+        }
+
+        writeTypeAndLength(3, utf8data.length);
+        return writeUint8Array(utf8data);
+
+      default:
+        var length;
+        if (Array.isArray(value)) {
+          length = value.length;
+          writeTypeAndLength(4, length);
+          for (i = 0; i < length; ++i)
+            encodeItem(value[i]);
+        } else if (value instanceof Uint8Array) {
+          writeTypeAndLength(2, value.length);
+          writeUint8Array(value);
+        } else {
+          var keys = Object.keys(value);
+          length = keys.length;
+          writeTypeAndLength(5, length);
+          for (i = 0; i < length; ++i) {
+            var key = keys[i];
+            encodeItem(key);
+            encodeItem(value[key]);
+          }
+        }
+    }
+  }
+
+  encodeItem(value);
+
+  if ("slice" in data)
+    return data.slice(0, offset);
+
+  var ret = new ArrayBuffer(offset);
+  var retView = new DataView(ret);
+  for (var i = 0; i < offset; ++i)
+    retView.setUint8(i, dataView.getUint8(i));
+  return ret;
+}
+
+function decode(data, tagger, simpleValue) {
+  var dataView = new DataView(data);
+  var offset = 0;
+
+  if (typeof tagger !== "function")
+    tagger = function(value) { return value; };
+  if (typeof simpleValue !== "function")
+    simpleValue = function() { return undefined; };
+
+  function commitRead(length, value) {
+    offset += length;
+    return value;
+  }
+  function readArrayBuffer(length) {
+    return commitRead(length, new Uint8Array(data, offset, length));
+  }
+  function readFloat16() {
+    var tempArrayBuffer = new ArrayBuffer(4);
+    var tempDataView = new DataView(tempArrayBuffer);
+    var value = readUint16();
+
+    var sign = value & 0x8000;
+    var exponent = value & 0x7c00;
+    var fraction = value & 0x03ff;
+
+    if (exponent === 0x7c00)
+      exponent = 0xff << 10;
+    else if (exponent !== 0)
+      exponent += (127 - 15) << 10;
+    else if (fraction !== 0)
+      return (sign ? -1 : 1) * fraction * POW_2_24;
+
+    tempDataView.setUint32(0, sign << 16 | exponent << 13 | fraction << 13);
+    return tempDataView.getFloat32(0);
+  }
+  function readFloat32() {
+    return commitRead(4, dataView.getFloat32(offset));
+  }
+  function readFloat64() {
+    return commitRead(8, dataView.getFloat64(offset));
+  }
+  function readUint8() {
+    return commitRead(1, dataView.getUint8(offset));
+  }
+  function readUint16() {
+    return commitRead(2, dataView.getUint16(offset));
+  }
+  function readUint32() {
+    return commitRead(4, dataView.getUint32(offset));
+  }
+  function readUint64() {
+    return readUint32() * POW_2_32 + readUint32();
+  }
+  function readBreak() {
+    if (dataView.getUint8(offset) !== 0xff)
+      return false;
+    offset += 1;
+    return true;
+  }
+  function readLength(additionalInformation) {
+    if (additionalInformation < 24)
+      return additionalInformation;
+    if (additionalInformation === 24)
+      return readUint8();
+    if (additionalInformation === 25)
+      return readUint16();
+    if (additionalInformation === 26)
+      return readUint32();
+    if (additionalInformation === 27)
+      return readUint64();
+    if (additionalInformation === 31)
+      return -1;
+    throw "Invalid length encoding";
+  }
+  function readIndefiniteStringLength(majorType) {
+    var initialByte = readUint8();
+    if (initialByte === 0xff)
+      return -1;
+    var length = readLength(initialByte & 0x1f);
+    if (length < 0 || (initialByte >> 5) !== majorType)
+      throw "Invalid indefinite length element";
+    return length;
+  }
+
+  function appendUtf16Data(utf16data, length) {
+    for (var i = 0; i < length; ++i) {
+      var value = readUint8();
+      if (value & 0x80) {
+        if (value < 0xe0) {
+          value = (value & 0x1f) <<  6
+                | (readUint8() & 0x3f);
+          length -= 1;
+        } else if (value < 0xf0) {
+          value = (value & 0x0f) << 12
+                | (readUint8() & 0x3f) << 6
+                | (readUint8() & 0x3f);
+          length -= 2;
+        } else {
+          value = (value & 0x0f) << 18
+                | (readUint8() & 0x3f) << 12
+                | (readUint8() & 0x3f) << 6
+                | (readUint8() & 0x3f);
+          length -= 3;
+        }
+      }
+
+      if (value < 0x10000) {
+        utf16data.push(value);
+      } else {
+        value -= 0x10000;
+        utf16data.push(0xd800 | (value >> 10));
+        utf16data.push(0xdc00 | (value & 0x3ff));
+      }
+    }
+  }
+
+  function decodeItem() {
+    var initialByte = readUint8();
+    var majorType = initialByte >> 5;
+    var additionalInformation = initialByte & 0x1f;
+    var i;
+    var length;
+
+    if (majorType === 7) {
+      switch (additionalInformation) {
+        case 25:
+          return readFloat16();
+        case 26:
+          return readFloat32();
+        case 27:
+          return readFloat64();
+      }
+    }
+
+    length = readLength(additionalInformation);
+    if (length < 0 && (majorType < 2 || 6 < majorType))
+      throw "Invalid length";
+
+    switch (majorType) {
+      case 0:
+        return length;
+      case 1:
+        return -1 - length;
+      case 2:
+        if (length < 0) {
+          var elements = [];
+          var fullArrayLength = 0;
+          while ((length = readIndefiniteStringLength(majorType)) >= 0) {
+            fullArrayLength += length;
+            elements.push(readArrayBuffer(length));
+          }
+          var fullArray = new Uint8Array(fullArrayLength);
+          var fullArrayOffset = 0;
+          for (i = 0; i < elements.length; ++i) {
+            fullArray.set(elements[i], fullArrayOffset);
+            fullArrayOffset += elements[i].length;
+          }
+          return fullArray;
+        }
+        return readArrayBuffer(length);
+      case 3:
+        var utf16data = [];
+        if (length < 0) {
+          while ((length = readIndefiniteStringLength(majorType)) >= 0)
+            appendUtf16Data(utf16data, length);
+        } else
+          appendUtf16Data(utf16data, length);
+        return String.fromCharCode.apply(null, utf16data);
+      case 4:
+        var retArray;
+        if (length < 0) {
+          retArray = [];
+          while (!readBreak())
+            retArray.push(decodeItem());
+        } else {
+          retArray = new Array(length);
+          for (i = 0; i < length; ++i)
+            retArray[i] = decodeItem();
+        }
+        return retArray;
+      case 5:
+        var retObject = {};
+        for (i = 0; i < length || length < 0 && !readBreak(); ++i) {
+          var key = decodeItem();
+          retObject[key] = decodeItem();
+        }
+        return retObject;
+      case 6:
+        return tagger(decodeItem(), length);
+      case 7:
+        switch (length) {
+          case 20:
+            return false;
+          case 21:
+            return true;
+          case 22:
+            return null;
+          case 23:
+            return undefined;
+          default:
+            return simpleValue(length);
+        }
+    }
+  }
+
+  var ret = decodeItem();
+  if (offset !== data.byteLength)
+    throw "Remaining bytes";
+  return ret;
+}
+
+var obj = { encode: encode, decode: decode };
+
+if (typeof define === "function" && define.amd)
+  define("cbor/cbor", obj);
+else if (typeof module !== "undefined" && module.exports)
+  module.exports = obj;
+else if (!global.CBOR)
+  global.CBOR = obj;
+
+})(this);

example/static/mfa/js/u2f-api.js

@@ -0,0 +1,751 @@
+//Copyright 2014-2015 Google Inc. All rights reserved.
+
+//Use of this source code is governed by a BSD-style
+//license that can be found in the LICENSE file or at
+//https://developers.google.com/open-source/licenses/bsd
+
+/**
+ * @fileoverview The U2F api.
+ */
+'use strict';
+
+
+/**
+ * Namespace for the U2F api.
+ * @type {Object}
+ */
+var u2f = u2f || {};
+
+/**
+ * FIDO U2F Javascript API Version
+ * @number
+ */
+var js_api_version;
+
+/**
+ * The U2F extension id
+ * @const {string}
+ */
+// The Chrome packaged app extension ID.
+// Uncomment this if you want to deploy a server instance that uses
+// the package Chrome app and does not require installing the U2F Chrome extension.
+ u2f.EXTENSION_ID = 'kmendfapggjehodndflmmgagdbamhnfd';
+// The U2F Chrome extension ID.
+// Uncomment this if you want to deploy a server instance that uses
+// the U2F Chrome extension to authenticate.
+// u2f.EXTENSION_ID = 'pfboblefjcgdjicmnffhdgionmgcdmne';
+
+
+/**
+ * Message types for messsages to/from the extension
+ * @const
+ * @enum {string}
+ */
+u2f.MessageTypes = {
+    'U2F_REGISTER_REQUEST': 'u2f_register_request',
+    'U2F_REGISTER_RESPONSE': 'u2f_register_response',
+    'U2F_SIGN_REQUEST': 'u2f_sign_request',
+    'U2F_SIGN_RESPONSE': 'u2f_sign_response',
+    'U2F_GET_API_VERSION_REQUEST': 'u2f_get_api_version_request',
+    'U2F_GET_API_VERSION_RESPONSE': 'u2f_get_api_version_response'
+};
+
+
+/**
+ * Response status codes
+ * @const
+ * @enum {number}
+ */
+u2f.ErrorCodes = {
+    'OK': 0,
+    'OTHER_ERROR': 1,
+    'BAD_REQUEST': 2,
+    'CONFIGURATION_UNSUPPORTED': 3,
+    'DEVICE_INELIGIBLE': 4,
+    'TIMEOUT': 5
+};
+
+
+/**
+ * A message for registration requests
+ * @typedef {{
+ *   type: u2f.MessageTypes,
+ *   appId: ?string,
+ *   timeoutSeconds: ?number,
+ *   requestId: ?number
+ * }}
+ */
+u2f.U2fRequest;
+
+
+/**
+ * A message for registration responses
+ * @typedef {{
+ *   type: u2f.MessageTypes,
+ *   responseData: (u2f.Error | u2f.RegisterResponse | u2f.SignResponse),
+ *   requestId: ?number
+ * }}
+ */
+u2f.U2fResponse;
+
+
+/**
+ * An error object for responses
+ * @typedef {{
+ *   errorCode: u2f.ErrorCodes,
+ *   errorMessage: ?string
+ * }}
+ */
+u2f.Error;
+
+/**
+ * Data object for a single sign request.
+ * @typedef {enum {BLUETOOTH_RADIO, BLUETOOTH_LOW_ENERGY, USB, NFC}}
+ */
+u2f.Transport;
+
+
+/**
+ * Data object for a single sign request.
+ * @typedef {Array<u2f.Transport>}
+ */
+u2f.Transports;
+
+/**
+ * Data object for a single sign request.
+ * @typedef {{
+ *   version: string,
+ *   challenge: string,
+ *   keyHandle: string,
+ *   appId: string
+ * }}
+ */
+u2f.SignRequest;
+
+
+/**
+ * Data object for a sign response.
+ * @typedef {{
+ *   keyHandle: string,
+ *   signatureData: string,
+ *   clientData: string
+ * }}
+ */
+u2f.SignResponse;
+
+
+/**
+ * Data object for a registration request.
+ * @typedef {{
+ *   version: string,
+ *   challenge: string
+ * }}
+ */
+u2f.RegisterRequest;
+
+
+/**
+ * Data object for a registration response.
+ * @typedef {{
+ *   version: string,
+ *   keyHandle: string,
+ *   transports: Transports,
+ *   appId: string
+ * }}
+ */
+u2f.RegisterResponse;
+
+
+/**
+ * Data object for a registered key.
+ * @typedef {{
+ *   version: string,
+ *   keyHandle: string,
+ *   transports: ?Transports,
+ *   appId: ?string
+ * }}
+ */
+u2f.RegisteredKey;
+
+
+/**
+ * Data object for a get API register response.
+ * @typedef {{
+ *   js_api_version: number
+ * }}
+ */
+u2f.GetJsApiVersionResponse;
+
+
+//Low level MessagePort API support
+
+/**
+ * Sets up a MessagePort to the U2F extension using the
+ * available mechanisms.
+ * @param {function((MessagePort|u2f.WrappedChromeRuntimePort_))} callback
+ */
+u2f.getMessagePort = function(callback) {
+  if (typeof chrome != 'undefined' && chrome.runtime) {
+    // The actual message here does not matter, but we need to get a reply
+    // for the callback to run. Thus, send an empty signature request
+    // in order to get a failure response.
+    var msg = {
+        type: u2f.MessageTypes.U2F_SIGN_REQUEST,
+        signRequests: []
+    };
+    chrome.runtime.sendMessage(u2f.EXTENSION_ID, msg, function() {
+      if (!chrome.runtime.lastError) {
+        // We are on a whitelisted origin and can talk directly
+        // with the extension.
+        u2f.getChromeRuntimePort_(callback);
+      } else {
+        // chrome.runtime was available, but we couldn't message
+        // the extension directly, use iframe
+        u2f.getIframePort_(callback);
+      }
+    });
+  } else if (u2f.isAndroidChrome_()) {
+    u2f.getAuthenticatorPort_(callback);
+  } else if (u2f.isIosChrome_()) {
+    u2f.getIosPort_(callback);
+  } else {
+    // chrome.runtime was not available at all, which is normal
+    // when this origin doesn't have access to any extensions.
+    u2f.getIframePort_(callback);
+  }
+};
+
+/**
+ * Detect chrome running on android based on the browser's useragent.
+ * @private
+ */
+u2f.isAndroidChrome_ = function() {
+  var userAgent = navigator.userAgent;
+  return userAgent.indexOf('Chrome') != -1 &&
+  userAgent.indexOf('Android') != -1;
+};
+
+/**
+ * Detect chrome running on iOS based on the browser's platform.
+ * @private
+ */
+u2f.isIosChrome_ = function() {
+  return ["iPhone", "iPad", "iPod"].indexOf(navigator.platform) > -1;
+};
+
+/**
+ * Connects directly to the extension via chrome.runtime.connect.
+ * @param {function(u2f.WrappedChromeRuntimePort_)} callback
+ * @private
+ */
+u2f.getChromeRuntimePort_ = function(callback) {
+  var port = chrome.runtime.connect(u2f.EXTENSION_ID,
+      {'includeTlsChannelId': true});
+  setTimeout(function() {
+    callback(new u2f.WrappedChromeRuntimePort_(port));
+  }, 0);
+};
+
+/**
+ * Return a 'port' abstraction to the Authenticator app.
+ * @param {function(u2f.WrappedAuthenticatorPort_)} callback
+ * @private
+ */
+u2f.getAuthenticatorPort_ = function(callback) {
+  setTimeout(function() {
+    callback(new u2f.WrappedAuthenticatorPort_());
+  }, 0);
+};
+
+/**
+ * Return a 'port' abstraction to the iOS client app.
+ * @param {function(u2f.WrappedIosPort_)} callback
+ * @private
+ */
+u2f.getIosPort_ = function(callback) {
+  setTimeout(function() {
+    callback(new u2f.WrappedIosPort_());
+  }, 0);
+};
+
+/**
+ * A wrapper for chrome.runtime.Port that is compatible with MessagePort.
+ * @param {Port} port
+ * @constructor
+ * @private
+ */
+u2f.WrappedChromeRuntimePort_ = function(port) {
+  this.port_ = port;
+};
+
+/**
+ * Format and return a sign request compliant with the JS API version supported by the extension.
+ * @param {Array<u2f.SignRequest>} signRequests
+ * @param {number} timeoutSeconds
+ * @param {number} reqId
+ * @return {Object}
+ */
+u2f.formatSignRequest_ =
+  function(appId, challenge, registeredKeys, timeoutSeconds, reqId) {
+  if (js_api_version === undefined || js_api_version < 1.1) {
+    // Adapt request to the 1.0 JS API
+    var signRequests = [];
+    for (var i = 0; i < registeredKeys.length; i++) {
+      signRequests[i] = {
+          version: registeredKeys[i].version,
+          challenge: challenge,
+          keyHandle: registeredKeys[i].keyHandle,
+          appId: appId
+      };
+    }
+    return {
+      type: u2f.MessageTypes.U2F_SIGN_REQUEST,
+      signRequests: signRequests,
+      timeoutSeconds: timeoutSeconds,
+      requestId: reqId
+    };
+  }
+  // JS 1.1 API
+  return {
+    type: u2f.MessageTypes.U2F_SIGN_REQUEST,
+    appId: appId,
+    challenge: challenge,
+    registeredKeys: registeredKeys,
+    timeoutSeconds: timeoutSeconds,
+    requestId: reqId
+  };
+};
+
+/**
+ * Format and return a register request compliant with the JS API version supported by the extension..
+ * @param {Array<u2f.SignRequest>} signRequests
+ * @param {Array<u2f.RegisterRequest>} signRequests
+ * @param {number} timeoutSeconds
+ * @param {number} reqId
+ * @return {Object}
+ */
+u2f.formatRegisterRequest_ =
+  function(appId, registeredKeys, registerRequests, timeoutSeconds, reqId) {
+  if (js_api_version === undefined || js_api_version < 1.1) {
+    // Adapt request to the 1.0 JS API
+    for (var i = 0; i < registerRequests.length; i++) {
+      registerRequests[i].appId = appId;
+    }
+    var signRequests = [];
+    for (var i = 0; i < registeredKeys.length; i++) {
+      signRequests[i] = {
+          version: registeredKeys[i].version,
+          challenge: registerRequests[0],
+          keyHandle: registeredKeys[i].keyHandle,
+          appId: appId
+      };
+    }
+    return {
+      type: u2f.MessageTypes.U2F_REGISTER_REQUEST,
+      signRequests: signRequests,
+      registerRequests: registerRequests,
+      timeoutSeconds: timeoutSeconds,
+      requestId: reqId
+    };
+  }
+  // JS 1.1 API
+  return {
+    type: u2f.MessageTypes.U2F_REGISTER_REQUEST,
+    appId: appId,
+    registerRequests: registerRequests,
+    registeredKeys: registeredKeys,
+    timeoutSeconds: timeoutSeconds,
+    requestId: reqId
+  };
+};
+
+
+/**
+ * Posts a message on the underlying channel.
+ * @param {Object} message
+ */
+u2f.WrappedChromeRuntimePort_.prototype.postMessage = function(message) {
+  this.port_.postMessage(message);
+};
+
+
+/**
+ * Emulates the HTML 5 addEventListener interface. Works only for the
+ * onmessage event, which is hooked up to the chrome.runtime.Port.onMessage.
+ * @param {string} eventName
+ * @param {function({data: Object})} handler
+ */
+u2f.WrappedChromeRuntimePort_.prototype.addEventListener =
+    function(eventName, handler) {
+  var name = eventName.toLowerCase();
+  if (name == 'message' || name == 'onmessage') {
+    this.port_.onMessage.addListener(function(message) {
+      // Emulate a minimal MessageEvent object
+      handler({'data': message});
+    });
+  } else {
+    console.error('WrappedChromeRuntimePort only supports onMessage');
+  }
+};
+
+/**
+ * Wrap the Authenticator app with a MessagePort interface.
+ * @constructor
+ * @private
+ */
+u2f.WrappedAuthenticatorPort_ = function() {
+  this.requestId_ = -1;
+  this.requestObject_ = null;
+}
+
+/**
+ * Launch the Authenticator intent.
+ * @param {Object} message
+ */
+u2f.WrappedAuthenticatorPort_.prototype.postMessage = function(message) {
+  var intentUrl =
+    u2f.WrappedAuthenticatorPort_.INTENT_URL_BASE_ +
+    ';S.request=' + encodeURIComponent(JSON.stringify(message)) +
+    ';end';
+  document.location = intentUrl;
+};
+
+/**
+ * Tells what type of port this is.
+ * @return {String} port type
+ */
+u2f.WrappedAuthenticatorPort_.prototype.getPortType = function() {
+  return "WrappedAuthenticatorPort_";
+};
+
+
+/**
+ * Emulates the HTML 5 addEventListener interface.
+ * @param {string} eventName
+ * @param {function({data: Object})} handler
+ */
+u2f.WrappedAuthenticatorPort_.prototype.addEventListener = function(eventName, handler) {
+  var name = eventName.toLowerCase();
+  if (name == 'message') {
+    var self = this;
+    /* Register a callback to that executes when
+     * chrome injects the response. */
+    window.addEventListener(
+        'message', self.onRequestUpdate_.bind(self, handler), false);
+  } else {
+    console.error('WrappedAuthenticatorPort only supports message');
+  }
+};
+
+/**
+ * Callback invoked  when a response is received from the Authenticator.
+ * @param function({data: Object}) callback
+ * @param {Object} message message Object
+ */
+u2f.WrappedAuthenticatorPort_.prototype.onRequestUpdate_ =
+    function(callback, message) {
+  var messageObject = JSON.parse(message.data);
+  var intentUrl = messageObject['intentURL'];
+
+  var errorCode = messageObject['errorCode'];
+  var responseObject = null;
+  if (messageObject.hasOwnProperty('data')) {
+    responseObject = /** @type {Object} */ (
+        JSON.parse(messageObject['data']));
+  }
+
+  callback({'data': responseObject});
+};
+
+/**
+ * Base URL for intents to Authenticator.
+ * @const
+ * @private
+ */
+u2f.WrappedAuthenticatorPort_.INTENT_URL_BASE_ =
+  'intent:#Intent;action=com.google.android.apps.authenticator.AUTHENTICATE';
+
+/**
+ * Wrap the iOS client app with a MessagePort interface.
+ * @constructor
+ * @private
+ */
+u2f.WrappedIosPort_ = function() {};
+
+/**
+ * Launch the iOS client app request
+ * @param {Object} message
+ */
+u2f.WrappedIosPort_.prototype.postMessage = function(message) {
+  var str = JSON.stringify(message);
+  var url = "u2f://auth?" + encodeURI(str);
+  location.replace(url);
+};
+
+/**
+ * Tells what type of port this is.
+ * @return {String} port type
+ */
+u2f.WrappedIosPort_.prototype.getPortType = function() {
+  return "WrappedIosPort_";
+};
+
+/**
+ * Emulates the HTML 5 addEventListener interface.
+ * @param {string} eventName
+ * @param {function({data: Object})} handler
+ */
+u2f.WrappedIosPort_.prototype.addEventListener = function(eventName, handler) {
+  var name = eventName.toLowerCase();
+  if (name !== 'message') {
+    console.error('WrappedIosPort only supports message');
+  }
+};
+
+/**
+ * Sets up an embedded trampoline iframe, sourced from the extension.
+ * @param {function(MessagePort)} callback
+ * @private
+ */
+u2f.getIframePort_ = function(callback) {
+  // Create the iframe
+  var iframeOrigin = 'chrome-extension://' + u2f.EXTENSION_ID;
+  var iframe = document.createElement('iframe');
+  iframe.src = iframeOrigin + '/u2f-comms.html';
+  iframe.setAttribute('style', 'display:none');
+  document.body.appendChild(iframe);
+
+  var channel = new MessageChannel();
+  var ready = function(message) {
+    if (message.data == 'ready') {
+      channel.port1.removeEventListener('message', ready);
+      callback(channel.port1);
+    } else {
+      console.error('First event on iframe port was not "ready"');
+    }
+  };
+  channel.port1.addEventListener('message', ready);
+  channel.port1.start();
+
+  iframe.addEventListener('load', function() {
+    // Deliver the port to the iframe and initialize
+    iframe.contentWindow.postMessage('init', iframeOrigin, [channel.port2]);
+  });
+};
+
+
+//High-level JS API
+
+/**
+ * Default extension response timeout in seconds.
+ * @const
+ */
+u2f.EXTENSION_TIMEOUT_SEC = 30;
+
+/**
+ * A singleton instance for a MessagePort to the extension.
+ * @type {MessagePort|u2f.WrappedChromeRuntimePort_}
+ * @private
+ */
+u2f.port_ = null;
+
+/**
+ * Callbacks waiting for a port
+ * @type {Array<function((MessagePort|u2f.WrappedChromeRuntimePort_))>}
+ * @private
+ */
+u2f.waitingForPort_ = [];
+
+/**
+ * A counter for requestIds.
+ * @type {number}
+ * @private
+ */
+u2f.reqCounter_ = 0;
+
+/**
+ * A map from requestIds to client callbacks
+ * @type {Object.<number,(function((u2f.Error|u2f.RegisterResponse))
+ *                       |function((u2f.Error|u2f.SignResponse)))>}
+ * @private
+ */
+u2f.callbackMap_ = {};
+
+/**
+ * Creates or retrieves the MessagePort singleton to use.
+ * @param {function((MessagePort|u2f.WrappedChromeRuntimePort_))} callback
+ * @private
+ */
+u2f.getPortSingleton_ = function(callback) {
+  if (u2f.port_) {
+    callback(u2f.port_);
+  } else {
+    if (u2f.waitingForPort_.length == 0) {
+      u2f.getMessagePort(function(port) {
+        u2f.port_ = port;
+        u2f.port_.addEventListener('message',
+            /** @type {function(Event)} */ (u2f.responseHandler_));
+
+        // Careful, here be async callbacks. Maybe.
+        while (u2f.waitingForPort_.length)
+          u2f.waitingForPort_.shift()(u2f.port_);
+      });
+    }
+    u2f.waitingForPort_.push(callback);
+  }
+};
+
+/**
+ * Handles response messages from the extension.
+ * @param {MessageEvent.<u2f.Response>} message
+ * @private
+ */
+u2f.responseHandler_ = function(message) {
+  var response = message.data;
+  var reqId = response['requestId'];
+  if (!reqId || !u2f.callbackMap_[reqId]) {
+    console.error('Unknown or missing requestId in response.');
+    return;
+  }
+  var cb = u2f.callbackMap_[reqId];
+  delete u2f.callbackMap_[reqId];
+  cb(response['responseData']);
+};
+
+/**
+ * Dispatches an array of sign requests to available U2F tokens.
+ * If the JS API version supported by the extension is unknown, it first sends a
+ * message to the extension to find out the supported API version and then it sends
+ * the sign request.
+ * @param {string=} appId
+ * @param {string=} challenge
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.SignResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.sign = function(appId, challenge, registeredKeys, callback, opt_timeoutSeconds) {
+  if (js_api_version === undefined) {
+    // Send a message to get the extension to JS API version, then send the actual sign request.
+    u2f.getApiVersion(
+        function (response) {
+          js_api_version = response['js_api_version'] === undefined ? 0 : response['js_api_version'];
+          console.log("Extension JS API Version: ", js_api_version);
+          u2f.sendSignRequest(appId, challenge, registeredKeys, callback, opt_timeoutSeconds);
+        });
+  } else {
+    // We know the JS API version. Send the actual sign request in the supported API version.
+    u2f.sendSignRequest(appId, challenge, registeredKeys, callback, opt_timeoutSeconds);
+  }
+};
+
+/**
+ * Dispatches an array of sign requests to available U2F tokens.
+ * @param {string=} appId
+ * @param {string=} challenge
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.SignResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.sendSignRequest = function(appId, challenge, registeredKeys, callback, opt_timeoutSeconds) {
+  u2f.getPortSingleton_(function(port) {
+    var reqId = ++u2f.reqCounter_;
+    u2f.callbackMap_[reqId] = callback;
+    var timeoutSeconds = (typeof opt_timeoutSeconds !== 'undefined' ?
+        opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC);
+    var req = u2f.formatSignRequest_(appId, challenge, registeredKeys, timeoutSeconds, reqId);
+    port.postMessage(req);
+  });
+};
+
+/**
+ * Dispatches register requests to available U2F tokens. An array of sign
+ * requests identifies already registered tokens.
+ * If the JS API version supported by the extension is unknown, it first sends a
+ * message to the extension to find out the supported API version and then it sends
+ * the register request.
+ * @param {string=} appId
+ * @param {Array<u2f.RegisterRequest>} registerRequests
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.RegisterResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.register = function(appId, registerRequests, registeredKeys, callback, opt_timeoutSeconds) {
+  console.log("appid",appId)
+  console.log("registerRequests",registerRequests)
+  console.log("registeredKeys",registeredKeys)
+  if (js_api_version === undefined) {
+    // Send a message to get the extension to JS API version, then send the actual register request.
+    u2f.getApiVersion(
+        function (response) {
+          js_api_version = response['js_api_version'] === undefined ? 0: response['js_api_version'];
+          console.log("Extension JS API Version: ", js_api_version);
+          u2f.sendRegisterRequest(appId, registerRequests, registeredKeys,
+              callback, opt_timeoutSeconds);
+        });
+  } else {
+    // We know the JS API version. Send the actual register request in the supported API version.
+    u2f.sendRegisterRequest(appId, registerRequests, registeredKeys,
+        callback, opt_timeoutSeconds);
+  }
+};
+
+/**
+ * Dispatches register requests to available U2F tokens. An array of sign
+ * requests identifies already registered tokens.
+ * @param {string=} appId
+ * @param {Array<u2f.RegisterRequest>} registerRequests
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.RegisterResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.sendRegisterRequest = function(appId, registerRequests, registeredKeys, callback, opt_timeoutSeconds) {
+  u2f.getPortSingleton_(function(port) {
+    var reqId = ++u2f.reqCounter_;
+    u2f.callbackMap_[reqId] = callback;
+    var timeoutSeconds = (typeof opt_timeoutSeconds !== 'undefined' ?
+        opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC);
+    var req = u2f.formatRegisterRequest_(
+        appId, registeredKeys, registerRequests, timeoutSeconds, reqId);
+    port.postMessage(req);
+  });
+};
+
+
+/**
+ * Dispatches a message to the extension to find out the supported
+ * JS API version.
+ * If the user is on a mobile phone and is thus using Google Authenticator instead
+ * of the Chrome extension, don't send the request and simply return 0.
+ * @param {function((u2f.Error|u2f.GetJsApiVersionResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.getApiVersion = function(callback, opt_timeoutSeconds) {
+ u2f.getPortSingleton_(function(port) {
+   // If we are using Android Google Authenticator or iOS client app,
+   // do not fire an intent to ask which JS API version to use.
+   if (port.getPortType) {
+     var apiVersion;
+     switch (port.getPortType()) {
+       case 'WrappedIosPort_':
+       case 'WrappedAuthenticatorPort_':
+         apiVersion = 1.1;
+         break;
+
+       default:
+         apiVersion = 0;
+         break;
+     }
+     callback({ 'js_api_version': apiVersion });
+     return;
+   }
+    var reqId = ++u2f.reqCounter_;
+    u2f.callbackMap_[reqId] = callback;
+    var req = {
+      type: u2f.MessageTypes.U2F_GET_API_VERSION_REQUEST,
+      timeoutSeconds: (typeof opt_timeoutSeconds !== 'undefined' ?
+          opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC),
+      requestId: reqId
+    };
+    port.postMessage(req);
+  });
+};

example/static/vendor/bootstrap/scss/_alert.scss

@@ -0,0 +1,51 @@
+//
+// Base styles
+//
+
+.alert {
+  position: relative;
+  padding: $alert-padding-y $alert-padding-x;
+  margin-bottom: $alert-margin-bottom;
+  border: $alert-border-width solid transparent;
+  @include border-radius($alert-border-radius);
+}
+
+// Headings for larger alerts
+.alert-heading {
+  // Specified to prevent conflicts of changing $headings-color
+  color: inherit;
+}
+
+// Provide class for links that match alerts
+.alert-link {
+  font-weight: $alert-link-font-weight;
+}
+
+
+// Dismissible alerts
+//
+// Expand the right padding and account for the close button's positioning.
+
+.alert-dismissible {
+  padding-right: $close-font-size + $alert-padding-x * 2;
+
+  // Adjust close link position
+  .close {
+    position: absolute;
+    top: 0;
+    right: 0;
+    padding: $alert-padding-y $alert-padding-x;
+    color: inherit;
+  }
+}
+
+
+// Alternate styles
+//
+// Generate contextual modifier classes for colorizing the alert.
+
+@each $color, $value in $theme-colors {
+  .alert-#{$color} {
+    @include alert-variant(theme-color-level($color, $alert-bg-level), theme-color-level($color, $alert-border-level), theme-color-level($color, $alert-color-level));
+  }
+}

example/static/vendor/bootstrap/scss/_badge.scss

@@ -0,0 +1,54 @@
+// Base class
+//
+// Requires one of the contextual, color modifier classes for `color` and
+// `background-color`.
+
+.badge {
+  display: inline-block;
+  padding: $badge-padding-y $badge-padding-x;
+  @include font-size($badge-font-size);
+  font-weight: $badge-font-weight;
+  line-height: 1;
+  text-align: center;
+  white-space: nowrap;
+  vertical-align: baseline;
+  @include border-radius($badge-border-radius);
+  @include transition($badge-transition);
+
+  @at-root a#{&} {
+    @include hover-focus {
+      text-decoration: none;
+    }
+  }
+
+  // Empty badges collapse automatically
+  &:empty {
+    display: none;
+  }
+}
+
+// Quick fix for badges in buttons
+.btn .badge {
+  position: relative;
+  top: -1px;
+}
+
+// Pill badges
+//
+// Make them extra rounded with a modifier to replace v3's badges.
+
+.badge-pill {
+  padding-right: $badge-pill-padding-x;
+  padding-left: $badge-pill-padding-x;
+  @include border-radius($badge-pill-border-radius);
+}
+
+// Colors
+//
+// Contextual variations (linked badges get darker on :hover).
+
+@each $color, $value in $theme-colors {
+  .badge-#{$color} {
+    @include badge-variant($value);
+  }
+}

example/static/vendor/bootstrap/scss/_breadcrumb.scss

@@ -0,0 +1,41 @@
+.breadcrumb {
+  display: flex;
+  flex-wrap: wrap;
+  padding: $breadcrumb-padding-y $breadcrumb-padding-x;
+  margin-bottom: $breadcrumb-margin-bottom;
+  list-style: none;
+  background-color: $breadcrumb-bg;
+  @include border-radius($breadcrumb-border-radius);
+}
+
+.breadcrumb-item {
+  // The separator between breadcrumbs (by default, a forward-slash: "/")
+  + .breadcrumb-item {
+    padding-left: $breadcrumb-item-padding;
+
+    &::before {
+      display: inline-block; // Suppress underlining of the separator in modern browsers
+      padding-right: $breadcrumb-item-padding;
+      color: $breadcrumb-divider-color;
+      content: $breadcrumb-divider;
+    }
+  }
+
+  // IE9-11 hack to properly handle hyperlink underlines for breadcrumbs built
+  // without `<ul>`s. The `::before` pseudo-element generates an element
+  // *within* the .breadcrumb-item and thereby inherits the `text-decoration`.
+  //
+  // To trick IE into suppressing the underline, we give the pseudo-element an
+  // underline and then immediately remove it.
+  + .breadcrumb-item:hover::before {
+    text-decoration: underline;
+  }
+  // stylelint-disable-next-line no-duplicate-selectors
+  + .breadcrumb-item:hover::before {
+    text-decoration: none;
+  }
+
+  &.active {
+    color: $breadcrumb-active-color;
+  }
+}

example/static/vendor/bootstrap/scss/_button-group.scss

@@ -0,0 +1,163 @@
+// stylelint-disable selector-no-qualifying-type
+
+// Make the div behave like a button
+.btn-group,
+.btn-group-vertical {
+  position: relative;
+  display: inline-flex;
+  vertical-align: middle; // match .btn alignment given font-size hack above
+
+  > .btn {
+    position: relative;
+    flex: 1 1 auto;
+
+    // Bring the hover, focused, and "active" buttons to the front to overlay
+    // the borders properly
+    @include hover {
+      z-index: 1;
+    }
+    &:focus,
+    &:active,
+    &.active {
+      z-index: 1;
+    }
+  }
+}
+
+// Optional: Group multiple button groups together for a toolbar
+.btn-toolbar {
+  display: flex;
+  flex-wrap: wrap;
+  justify-content: flex-start;
+
+  .input-group {
+    width: auto;
+  }
+}
+
+.btn-group {
+  // Prevent double borders when buttons are next to each other
+  > .btn:not(:first-child),
+  > .btn-group:not(:first-child) {
+    margin-left: -$btn-border-width;
+  }
+
+  // Reset rounded corners
+  > .btn:not(:last-child):not(.dropdown-toggle),
+  > .btn-group:not(:last-child) > .btn {
+    @include border-right-radius(0);
+  }
+
+  > .btn:not(:first-child),
+  > .btn-group:not(:first-child) > .btn {
+    @include border-left-radius(0);
+  }
+}
+
+// Sizing
+//
+// Remix the default button sizing classes into new ones for easier manipulation.
+
+.btn-group-sm > .btn { @extend .btn-sm; }
+.btn-group-lg > .btn { @extend .btn-lg; }
+
+
+//
+// Split button dropdowns
+//
+
+.dropdown-toggle-split {
+  padding-right: $btn-padding-x * .75;
+  padding-left: $btn-padding-x * .75;
+
+  &::after,
+  .dropup &::after,
+  .dropright &::after {
+    margin-left: 0;
+  }
+
+  .dropleft &::before {
+    margin-right: 0;
+  }
+}
+
+.btn-sm + .dropdown-toggle-split {
+  padding-right: $btn-padding-x-sm * .75;
+  padding-left: $btn-padding-x-sm * .75;
+}
+
+.btn-lg + .dropdown-toggle-split {
+  padding-right: $btn-padding-x-lg * .75;
+  padding-left: $btn-padding-x-lg * .75;
+}
+
+
+// The clickable button for toggling the menu
+// Set the same inset shadow as the :active state
+.btn-group.show .dropdown-toggle {
+  @include box-shadow($btn-active-box-shadow);
+
+  // Show no shadow for `.btn-link` since it has no other button styles.
+  &.btn-link {
+    @include box-shadow(none);
+  }
+}
+
+
+//
+// Vertical button groups
+//
+
+.btn-group-vertical {
+  flex-direction: column;
+  align-items: flex-start;
+  justify-content: center;
+
+  > .btn,
+  > .btn-group {
+    width: 100%;
+  }
+
+  > .btn:not(:first-child),
+  > .btn-group:not(:first-child) {
+    margin-top: -$btn-border-width;
+  }
+
+  // Reset rounded corners
+  > .btn:not(:last-child):not(.dropdown-toggle),
+  > .btn-group:not(:last-child) > .btn {
+    @include border-bottom-radius(0);
+  }
+
+  > .btn:not(:first-child),
+  > .btn-group:not(:first-child) > .btn {
+    @include border-top-radius(0);
+  }
+}
+
+
+// Checkbox and radio options
+//
+// In order to support the browser's form validation feedback, powered by the
+// `required` attribute, we have to "hide" the inputs via `clip`. We cannot use
+// `display: none;` or `visibility: hidden;` as that also hides the popover.
+// Simply visually hiding the inputs via `opacity` would leave them clickable in
+// certain cases which is prevented by using `clip` and `pointer-events`.
+// This way, we ensure a DOM element is visible to position the popover from.
+//
+// See https://github.com/twbs/bootstrap/pull/12794 and
+// https://github.com/twbs/bootstrap/pull/14559 for more information.
+
+.btn-group-toggle {
+  > .btn,
+  > .btn-group > .btn {
+    margin-bottom: 0; // Override default `<label>` value
+
+    input[type="radio"],
+    input[type="checkbox"] {
+      position: absolute;
+      clip: rect(0, 0, 0, 0);
+      pointer-events: none;
+    }
+  }
+}

example/static/vendor/bootstrap/scss/_buttons.scss

@@ -0,0 +1,137 @@
+// stylelint-disable selector-no-qualifying-type
+
+//
+// Base styles
+//
+
+.btn {
+  display: inline-block;
+  font-family: $btn-font-family;
+  font-weight: $btn-font-weight;
+  color: $body-color;
+  text-align: center;
+  vertical-align: middle;
+  user-select: none;
+  background-color: transparent;
+  border: $btn-border-width solid transparent;
+  @include button-size($btn-padding-y, $btn-padding-x, $btn-font-size, $btn-line-height, $btn-border-radius);
+  @include transition($btn-transition);
+
+  @include hover {
+    color: $body-color;
+    text-decoration: none;
+  }
+
+  &:focus,
+  &.focus {
+    outline: 0;
+    box-shadow: $btn-focus-box-shadow;
+  }
+
+  // Disabled comes first so active can properly restyle
+  &.disabled,
+  &:disabled {
+    opacity: $btn-disabled-opacity;
+    @include box-shadow(none);
+  }
+
+  &:not(:disabled):not(.disabled):active,
+  &:not(:disabled):not(.disabled).active {
+    @include box-shadow($btn-active-box-shadow);
+
+    &:focus {
+      @include box-shadow($btn-focus-box-shadow, $btn-active-box-shadow);
+    }
+  }
+}
+
+// Future-proof disabling of clicks on `<a>` elements
+a.btn.disabled,
+fieldset:disabled a.btn {
+  pointer-events: none;
+}
+
+
+//
+// Alternate buttons
+//
+
+@each $color, $value in $theme-colors {
+  .btn-#{$color} {
+    @include button-variant($value, $value);
+  }
+}
+
+@each $color, $value in $theme-colors {
+  .btn-outline-#{$color} {
+    @include button-outline-variant($value);
+  }
+}
+
+
+//
+// Link buttons
+//
+
+// Make a button look and behave like a link
+.btn-link {
+  font-weight: $font-weight-normal;
+  color: $link-color;
+  text-decoration: $link-decoration;
+
+  @include hover {
+    color: $link-hover-color;
+    text-decoration: $link-hover-decoration;
+  }
+
+  &:focus,
+  &.focus {
+    text-decoration: $link-hover-decoration;
+    box-shadow: none;
+  }
+
+  &:disabled,
+  &.disabled {
+    color: $btn-link-disabled-color;
+    pointer-events: none;
+  }
+
+  // No need for an active state here
+}
+
+
+//
+// Button Sizes
+//
+
+.btn-lg {
+  @include button-size($btn-padding-y-lg, $btn-padding-x-lg, $btn-font-size-lg, $btn-line-height-lg, $btn-border-radius-lg);
+}
+
+.btn-sm {
+  @include button-size($btn-padding-y-sm, $btn-padding-x-sm, $btn-font-size-sm, $btn-line-height-sm, $btn-border-radius-sm);
+}
+
+
+//
+// Block button
+//
+
+.btn-block {
+  display: block;
+  width: 100%;
+
+  // Vertically space out multiple block buttons
+  + .btn-block {
+    margin-top: $btn-block-spacing-y;
+  }
+}
+
+// Specificity overrides
+input[type="submit"],
+input[type="reset"],
+input[type="button"] {
+  &.btn-block {
+    width: 100%;
+  }
+}

example/static/vendor/bootstrap/scss/_card.scss

@@ -0,0 +1,289 @@
+//
+// Base styles
+//
+
+.card {
+  position: relative;
+  display: flex;
+  flex-direction: column;
+  min-width: 0; // See https://github.com/twbs/bootstrap/pull/22740#issuecomment-305868106
+  word-wrap: break-word;
+  background-color: $card-bg;
+  background-clip: border-box;
+  border: $card-border-width solid $card-border-color;
+  @include border-radius($card-border-radius);
+
+  > hr {
+    margin-right: 0;
+    margin-left: 0;
+  }
+
+  > .list-group:first-child {
+    .list-group-item:first-child {
+      @include border-top-radius($card-border-radius);
+    }
+  }
+
+  > .list-group:last-child {
+    .list-group-item:last-child {
+      @include border-bottom-radius($card-border-radius);
+    }
+  }
+}
+
+.card-body {
+  // Enable `flex-grow: 1` for decks and groups so that card blocks take up
+  // as much space as possible, ensuring footers are aligned to the bottom.
+  flex: 1 1 auto;
+  padding: $card-spacer-x;
+  color: $card-color;
+}
+
+.card-title {
+  margin-bottom: $card-spacer-y;
+}
+
+.card-subtitle {
+  margin-top: -$card-spacer-y / 2;
+  margin-bottom: 0;
+}
+
+.card-text:last-child {
+  margin-bottom: 0;
+}
+
+.card-link {
+  @include hover {
+    text-decoration: none;
+  }
+
+  + .card-link {
+    margin-left: $card-spacer-x;
+  }
+}
+
+//
+// Optional textual caps
+//
+
+.card-header {
+  padding: $card-spacer-y $card-spacer-x;
+  margin-bottom: 0; // Removes the default margin-bottom of <hN>
+  color: $card-cap-color;
+  background-color: $card-cap-bg;
+  border-bottom: $card-border-width solid $card-border-color;
+
+  &:first-child {
+    @include border-radius($card-inner-border-radius $card-inner-border-radius 0 0);
+  }
+
+  + .list-group {
+    .list-group-item:first-child {
+      border-top: 0;
+    }
+  }
+}
+
+.card-footer {
+  padding: $card-spacer-y $card-spacer-x;
+  background-color: $card-cap-bg;
+  border-top: $card-border-width solid $card-border-color;
+
+  &:last-child {
+    @include border-radius(0 0 $card-inner-border-radius $card-inner-border-radius);
+  }
+}
+
+
+//
+// Header navs
+//
+
+.card-header-tabs {
+  margin-right: -$card-spacer-x / 2;
+  margin-bottom: -$card-spacer-y;
+  margin-left: -$card-spacer-x / 2;
+  border-bottom: 0;
+}
+
+.card-header-pills {
+  margin-right: -$card-spacer-x / 2;
+  margin-left: -$card-spacer-x / 2;
+}
+
+// Card image
+.card-img-overlay {
+  position: absolute;
+  top: 0;
+  right: 0;
+  bottom: 0;
+  left: 0;
+  padding: $card-img-overlay-padding;
+}
+
+.card-img {
+  width: 100%; // Required because we use flexbox and this inherently applies align-self: stretch
+  @include border-radius($card-inner-border-radius);
+}
+
+// Card image caps
+.card-img-top {
+  width: 100%; // Required because we use flexbox and this inherently applies align-self: stretch
+  @include border-top-radius($card-inner-border-radius);
+}
+
+.card-img-bottom {
+  width: 100%; // Required because we use flexbox and this inherently applies align-self: stretch
+  @include border-bottom-radius($card-inner-border-radius);
+}
+
+
+// Card deck
+
+.card-deck {
+  display: flex;
+  flex-direction: column;
+
+  .card {
+    margin-bottom: $card-deck-margin;
+  }
+
+  @include media-breakpoint-up(sm) {
+    flex-flow: row wrap;
+    margin-right: -$card-deck-margin;
+    margin-left: -$card-deck-margin;
+
+    .card {
+      display: flex;
+      // Flexbugs #4: https://github.com/philipwalton/flexbugs#flexbug-4
+      flex: 1 0 0%;
+      flex-direction: column;
+      margin-right: $card-deck-margin;
+      margin-bottom: 0; // Override the default
+      margin-left: $card-deck-margin;
+    }
+  }
+}
+
+
+//
+// Card groups
+//
+
+.card-group {
+  display: flex;
+  flex-direction: column;
+
+  // The child selector allows nested `.card` within `.card-group`
+  // to display properly.
+  > .card {
+    margin-bottom: $card-group-margin;
+  }
+
+  @include media-breakpoint-up(sm) {
+    flex-flow: row wrap;
+    // The child selector allows nested `.card` within `.card-group`
+    // to display properly.
+    > .card {
+      // Flexbugs #4: https://github.com/philipwalton/flexbugs#flexbug-4
+      flex: 1 0 0%;
+      margin-bottom: 0;
+
+      + .card {
+        margin-left: 0;
+        border-left: 0;
+      }
+
+      // Handle rounded corners
+      @if $enable-rounded {
+        &:not(:last-child) {
+          @include border-right-radius(0);
+
+          .card-img-top,
+          .card-header {
+            // stylelint-disable-next-line property-blacklist
+            border-top-right-radius: 0;
+          }
+          .card-img-bottom,
+          .card-footer {
+            // stylelint-disable-next-line property-blacklist
+            border-bottom-right-radius: 0;
+          }
+        }
+
+        &:not(:first-child) {
+          @include border-left-radius(0);
+
+          .card-img-top,
+          .card-header {
+            // stylelint-disable-next-line property-blacklist
+            border-top-left-radius: 0;
+          }
+          .card-img-bottom,
+          .card-footer {
+            // stylelint-disable-next-line property-blacklist
+            border-bottom-left-radius: 0;
+          }
+        }
+      }
+    }
+  }
+}
+
+
+//
+// Columns
+//
+
+.card-columns {
+  .card {
+    margin-bottom: $card-columns-margin;
+  }
+
+  @include media-breakpoint-up(sm) {
+    column-count: $card-columns-count;
+    column-gap: $card-columns-gap;
+    orphans: 1;
+    widows: 1;
+
+    .card {
+      display: inline-block; // Don't let them vertically span multiple columns
+      width: 100%; // Don't let their width change
+    }
+  }
+}
+
+
+//
+// Accordion
+//
+
+.accordion {
+  > .card {
+    overflow: hidden;
+
+    &:not(:first-of-type) {
+      .card-header:first-child {
+        @include border-radius(0);
+      }
+
+      &:not(:last-of-type) {
+        border-bottom: 0;
+        @include border-radius(0);
+      }
+    }
+
+    &:first-of-type {
+      border-bottom: 0;
+      @include border-bottom-radius(0);
+    }
+
+    &:last-of-type {
+      @include border-top-radius(0);
+    }
+
+    .card-header {
+      margin-bottom: -$card-border-width;
+    }
+  }
+}

example/static/vendor/bootstrap/scss/_carousel.scss

@@ -0,0 +1,197 @@
+// Notes on the classes:
+//
+// 1. .carousel.pointer-event should ideally be pan-y (to allow for users to scroll vertically)
+//    even when their scroll action started on a carousel, but for compatibility (with Firefox)
+//    we're preventing all actions instead
+// 2. The .carousel-item-left and .carousel-item-right is used to indicate where
+//    the active slide is heading.
+// 3. .active.carousel-item is the current slide.
+// 4. .active.carousel-item-left and .active.carousel-item-right is the current
+//    slide in its in-transition state. Only one of these occurs at a time.
+// 5. .carousel-item-next.carousel-item-left and .carousel-item-prev.carousel-item-right
+//    is the upcoming slide in transition.
+
+.carousel {
+  position: relative;
+}
+
+.carousel.pointer-event {
+  touch-action: pan-y;
+}
+
+.carousel-inner {
+  position: relative;
+  width: 100%;
+  overflow: hidden;
+  @include clearfix();
+}
+
+.carousel-item {
+  position: relative;
+  display: none;
+  float: left;
+  width: 100%;
+  margin-right: -100%;
+  backface-visibility: hidden;
+  @include transition($carousel-transition);
+}
+
+.carousel-item.active,
+.carousel-item-next,
+.carousel-item-prev {
+  display: block;
+}
+
+.carousel-item-next:not(.carousel-item-left),
+.active.carousel-item-right {
+  transform: translateX(100%);
+}
+
+.carousel-item-prev:not(.carousel-item-right),
+.active.carousel-item-left {
+  transform: translateX(-100%);
+}
+
+
+//
+// Alternate transitions
+//
+
+.carousel-fade {
+  .carousel-item {
+    opacity: 0;
+    transition-property: opacity;
+    transform: none;
+  }
+
+  .carousel-item.active,
+  .carousel-item-next.carousel-item-left,
+  .carousel-item-prev.carousel-item-right {
+    z-index: 1;
+    opacity: 1;
+  }
+
+  .active.carousel-item-left,
+  .active.carousel-item-right {
+    z-index: 0;
+    opacity: 0;
+    @include transition(0s $carousel-transition-duration opacity);
+  }
+}
+
+
+//
+// Left/right controls for nav
+//
+
+.carousel-control-prev,
+.carousel-control-next {
+  position: absolute;
+  top: 0;
+  bottom: 0;
+  z-index: 1;
+  // Use flex for alignment (1-3)
+  display: flex; // 1. allow flex styles
+  align-items: center; // 2. vertically center contents
+  justify-content: center; // 3. horizontally center contents
+  width: $carousel-control-width;
+  color: $carousel-control-color;
+  text-align: center;
+  opacity: $carousel-control-opacity;
+  @include transition($carousel-control-transition);
+
+  // Hover/focus state
+  @include hover-focus {
+    color: $carousel-control-color;
+    text-decoration: none;
+    outline: 0;
+    opacity: $carousel-control-hover-opacity;
+  }
+}
+.carousel-control-prev {
+  left: 0;
+  @if $enable-gradients {
+    background: linear-gradient(90deg, rgba($black, .25), rgba($black, .001));
+  }
+}
+.carousel-control-next {
+  right: 0;
+  @if $enable-gradients {
+    background: linear-gradient(270deg, rgba($black, .25), rgba($black, .001));
+  }
+}
+
+// Icons for within
+.carousel-control-prev-icon,
+.carousel-control-next-icon {
+  display: inline-block;
+  width: $carousel-control-icon-width;
+  height: $carousel-control-icon-width;
+  background: no-repeat 50% / 100% 100%;
+}
+.carousel-control-prev-icon {
+  background-image: $carousel-control-prev-icon-bg;
+}
+.carousel-control-next-icon {
+  background-image: $carousel-control-next-icon-bg;
+}
+
+
+// Optional indicator pips
+//
+// Add an ordered list with the following class and add a list item for each
+// slide your carousel holds.
+
+.carousel-indicators {
+  position: absolute;
+  right: 0;
+  bottom: 0;
+  left: 0;
+  z-index: 15;
+  display: flex;
+  justify-content: center;
+  padding-left: 0; // override <ol> default
+  // Use the .carousel-control's width as margin so we don't overlay those
+  margin-right: $carousel-control-width;
+  margin-left: $carousel-control-width;
+  list-style: none;
+
+  li {
+    box-sizing: content-box;
+    flex: 0 1 auto;
+    width: $carousel-indicator-width;
+    height: $carousel-indicator-height;
+    margin-right: $carousel-indicator-spacer;
+    margin-left: $carousel-indicator-spacer;
+    text-indent: -999px;
+    cursor: pointer;
+    background-color: $carousel-indicator-active-bg;
+    background-clip: padding-box;
+    // Use transparent borders to increase the hit area by 10px on top and bottom.
+    border-top: $carousel-indicator-hit-area-height solid transparent;
+    border-bottom: $carousel-indicator-hit-area-height solid transparent;
+    opacity: .5;
+    @include transition($carousel-indicator-transition);
+  }
+
+  .active {
+    opacity: 1;
+  }
+}
+
+
+// Optional captions
+//
+//
+
+.carousel-caption {
+  position: absolute;
+  right: (100% - $carousel-caption-width) / 2;
+  bottom: 20px;
+  left: (100% - $carousel-caption-width) / 2;
+  z-index: 10;
+  padding-top: 20px;
+  padding-bottom: 20px;
+  color: $carousel-caption-color;
+  text-align: center;
+}

example/static/vendor/bootstrap/scss/_close.scss

@@ -0,0 +1,41 @@
+.close {
+  float: right;
+  @include font-size($close-font-size);
+  font-weight: $close-font-weight;
+  line-height: 1;
+  color: $close-color;
+  text-shadow: $close-text-shadow;
+  opacity: .5;
+
+  // Override <a>'s hover style
+  @include hover {
+    color: $close-color;
+    text-decoration: none;
+  }
+
+  &:not(:disabled):not(.disabled) {
+    @include hover-focus {
+      opacity: .75;
+    }
+  }
+}
+
+// Additional properties for button version
+// iOS requires the button element instead of an anchor tag.
+// If you want the anchor version, it requires `href="#"`.
+// See https://developer.mozilla.org/en-US/docs/Web/Events/click#Safari_Mobile
+
+// stylelint-disable-next-line selector-no-qualifying-type
+button.close {
+  padding: 0;
+  background-color: transparent;
+  border: 0;
+  appearance: none;
+}
+
+// Future-proof disabling of clicks on `<a>` elements
+
+// stylelint-disable-next-line selector-no-qualifying-type
+a.close.disabled {
+  pointer-events: none;
+}

example/static/vendor/bootstrap/scss/_code.scss

@@ -0,0 +1,48 @@
+// Inline code
+code {
+  @include font-size($code-font-size);
+  color: $code-color;
+  word-break: break-word;
+
+  // Streamline the style when inside anchors to avoid broken underline and more
+  a > & {
+    color: inherit;
+  }
+}
+
+// User input typically entered via keyboard
+kbd {
+  padding: $kbd-padding-y $kbd-padding-x;
+  @include font-size($kbd-font-size);
+  color: $kbd-color;
+  background-color: $kbd-bg;
+  @include border-radius($border-radius-sm);
+  @include box-shadow($kbd-box-shadow);
+
+  kbd {
+    padding: 0;
+    @include font-size(100%);
+    font-weight: $nested-kbd-font-weight;
+    @include box-shadow(none);
+  }
+}
+
+// Blocks of code
+pre {
+  display: block;
+  @include font-size($code-font-size);
+  color: $pre-color;
+
+  // Account for some code outputs that place code tags in pre tags
+  code {
+    @include font-size(inherit);
+    color: inherit;
+    word-break: normal;
+  }
+}
+
+// Enable scrollable blocks of code
+.pre-scrollable {
+  max-height: $pre-scrollable-max-height;
+  overflow-y: scroll;
+}

example/static/vendor/bootstrap/scss/_custom-forms.scss

@@ -0,0 +1,507 @@
+// Embedded icons from Open Iconic.
+// Released under MIT and copyright 2014 Waybury.
+// https://useiconic.com/open
+
+
+// Checkboxes and radios
+//
+// Base class takes care of all the key behavioral aspects.
+
+.custom-control {
+  position: relative;
+  display: block;
+  min-height: $font-size-base * $line-height-base;
+  padding-left: $custom-control-gutter + $custom-control-indicator-size;
+}
+
+.custom-control-inline {
+  display: inline-flex;
+  margin-right: $custom-control-spacer-x;
+}
+
+.custom-control-input {
+  position: absolute;
+  z-index: -1; // Put the input behind the label so it doesn't overlay text
+  opacity: 0;
+
+  &:checked ~ .custom-control-label::before {
+    color: $custom-control-indicator-checked-color;
+    border-color: $custom-control-indicator-checked-border-color;
+    @include gradient-bg($custom-control-indicator-checked-bg);
+    @include box-shadow($custom-control-indicator-checked-box-shadow);
+  }
+
+  &:focus ~ .custom-control-label::before {
+    // the mixin is not used here to make sure there is feedback
+    @if $enable-shadows {
+      box-shadow: $input-box-shadow, $input-focus-box-shadow;
+    } @else {
+      box-shadow: $custom-control-indicator-focus-box-shadow;
+    }
+  }
+
+  &:focus:not(:checked) ~ .custom-control-label::before {
+    border-color: $custom-control-indicator-focus-border-color;
+  }
+
+  &:not(:disabled):active ~ .custom-control-label::before {
+    color: $custom-control-indicator-active-color;
+    background-color: $custom-control-indicator-active-bg;
+    border-color: $custom-control-indicator-active-border-color;
+    @include box-shadow($custom-control-indicator-active-box-shadow);
+  }
+
+  &:disabled {
+    ~ .custom-control-label {
+      color: $custom-control-label-disabled-color;
+
+      &::before {
+        background-color: $custom-control-indicator-disabled-bg;
+      }
+    }
+  }
+}
+
+// Custom control indicators
+//
+// Build the custom controls out of pseudo-elements.
+
+.custom-control-label {
+  position: relative;
+  margin-bottom: 0;
+  vertical-align: top;
+
+  // Background-color and (when enabled) gradient
+  &::before {
+    position: absolute;
+    top: ($font-size-base * $line-height-base - $custom-control-indicator-size) / 2;
+    left: -($custom-control-gutter + $custom-control-indicator-size);
+    display: block;
+    width: $custom-control-indicator-size;
+    height: $custom-control-indicator-size;
+    pointer-events: none;
+    content: "";
+    background-color: $custom-control-indicator-bg;
+    border: $custom-control-indicator-border-color solid $custom-control-indicator-border-width;
+    @include box-shadow($custom-control-indicator-box-shadow);
+  }
+
+  // Foreground (icon)
+  &::after {
+    position: absolute;
+    top: ($font-size-base * $line-height-base - $custom-control-indicator-size) / 2;
+    left: -($custom-control-gutter + $custom-control-indicator-size);
+    display: block;
+    width: $custom-control-indicator-size;
+    height: $custom-control-indicator-size;
+    content: "";
+    background: no-repeat 50% / #{$custom-control-indicator-bg-size};
+  }
+}
+
+
+// Checkboxes
+//
+// Tweak just a few things for checkboxes.
+
+.custom-checkbox {
+  .custom-control-label::before {
+    @include border-radius($custom-checkbox-indicator-border-radius);
+  }
+
+  .custom-control-input:checked ~ .custom-control-label {
+    &::after {
+      background-image: $custom-checkbox-indicator-icon-checked;
+    }
+  }
+
+  .custom-control-input:indeterminate ~ .custom-control-label {
+    &::before {
+      border-color: $custom-checkbox-indicator-indeterminate-border-color;
+      @include gradient-bg($custom-checkbox-indicator-indeterminate-bg);
+      @include box-shadow($custom-checkbox-indicator-indeterminate-box-shadow);
+    }
+    &::after {
+      background-image: $custom-checkbox-indicator-icon-indeterminate;
+    }
+  }
+
+  .custom-control-input:disabled {
+    &:checked ~ .custom-control-label::before {
+      background-color: $custom-control-indicator-checked-disabled-bg;
+    }
+    &:indeterminate ~ .custom-control-label::before {
+      background-color: $custom-control-indicator-checked-disabled-bg;
+    }
+  }
+}
+
+// Radios
+//
+// Tweak just a few things for radios.
+
+.custom-radio {
+  .custom-control-label::before {
+    // stylelint-disable-next-line property-blacklist
+    border-radius: $custom-radio-indicator-border-radius;
+  }
+
+  .custom-control-input:checked ~ .custom-control-label {
+    &::after {
+      background-image: $custom-radio-indicator-icon-checked;
+    }
+  }
+
+  .custom-control-input:disabled {
+    &:checked ~ .custom-control-label::before {
+      background-color: $custom-control-indicator-checked-disabled-bg;
+    }
+  }
+}
+
+
+// switches
+//
+// Tweak a few things for switches
+
+.custom-switch {
+  padding-left: $custom-switch-width + $custom-control-gutter;
+
+  .custom-control-label {
+    &::before {
+      left: -($custom-switch-width + $custom-control-gutter);
+      width: $custom-switch-width;
+      pointer-events: all;
+      // stylelint-disable-next-line property-blacklist
+      border-radius: $custom-switch-indicator-border-radius;
+    }
+
+    &::after {
+      top: calc(#{(($font-size-base * $line-height-base - $custom-control-indicator-size) / 2)} + #{$custom-control-indicator-border-width * 2});
+      left: calc(#{-($custom-switch-width + $custom-control-gutter)} + #{$custom-control-indicator-border-width * 2});
+      width: $custom-switch-indicator-size;
+      height: $custom-switch-indicator-size;
+      background-color: $custom-control-indicator-border-color;
+      // stylelint-disable-next-line property-blacklist
+      border-radius: $custom-switch-indicator-border-radius;
+      @include transition(transform .15s ease-in-out, $custom-forms-transition);
+    }
+  }
+
+  .custom-control-input:checked ~ .custom-control-label {
+    &::after {
+      background-color: $custom-control-indicator-bg;
+      transform: translateX($custom-switch-width - $custom-control-indicator-size);
+    }
+  }
+
+  .custom-control-input:disabled {
+    &:checked ~ .custom-control-label::before {
+      background-color: $custom-control-indicator-checked-disabled-bg;
+    }
+  }
+}
+
+
+// Select
+//
+// Replaces the browser default select with a custom one, mostly pulled from
+// https://primer.github.io/.
+//
+
+.custom-select {
+  display: inline-block;
+  width: 100%;
+  height: $custom-select-height;
+  padding: $custom-select-padding-y ($custom-select-padding-x + $custom-select-indicator-padding) $custom-select-padding-y $custom-select-padding-x;
+  font-family: $custom-select-font-family;
+  @include font-size($custom-select-font-size);
+  font-weight: $custom-select-font-weight;
+  line-height: $custom-select-line-height;
+  color: $custom-select-color;
+  vertical-align: middle;
+  background: $custom-select-background;
+  background-color: $custom-select-bg;
+  border: $custom-select-border-width solid $custom-select-border-color;
+  @include border-radius($custom-select-border-radius, 0);
+  @include box-shadow($custom-select-box-shadow);
+  appearance: none;
+
+  &:focus {
+    border-color: $custom-select-focus-border-color;
+    outline: 0;
+    @if $enable-shadows {
+      box-shadow: $custom-select-box-shadow, $custom-select-focus-box-shadow;
+    } @else {
+      box-shadow: $custom-select-focus-box-shadow;
+    }
+
+    &::-ms-value {
+      // For visual consistency with other platforms/browsers,
+      // suppress the default white text on blue background highlight given to
+      // the selected option text when the (still closed) <select> receives focus
+      // in IE and (under certain conditions) Edge.
+      // See https://github.com/twbs/bootstrap/issues/19398.
+      color: $input-color;
+      background-color: $input-bg;
+    }
+  }
+
+  &[multiple],
+  &[size]:not([size="1"]) {
+    height: auto;
+    padding-right: $custom-select-padding-x;
+    background-image: none;
+  }
+
+  &:disabled {
+    color: $custom-select-disabled-color;
+    background-color: $custom-select-disabled-bg;
+  }
+
+  // Hides the default caret in IE11
+  &::-ms-expand {
+    display: none;
+  }
+}
+
+.custom-select-sm {
+  height: $custom-select-height-sm;
+  padding-top: $custom-select-padding-y-sm;
+  padding-bottom: $custom-select-padding-y-sm;
+  padding-left: $custom-select-padding-x-sm;
+  @include font-size($custom-select-font-size-sm);
+}
+
+.custom-select-lg {
+  height: $custom-select-height-lg;
+  padding-top: $custom-select-padding-y-lg;
+  padding-bottom: $custom-select-padding-y-lg;
+  padding-left: $custom-select-padding-x-lg;
+  @include font-size($custom-select-font-size-lg);
+}
+
+
+// File
+//
+// Custom file input.
+
+.custom-file {
+  position: relative;
+  display: inline-block;
+  width: 100%;
+  height: $custom-file-height;
+  margin-bottom: 0;
+}
+
+.custom-file-input {
+  position: relative;
+  z-index: 2;
+  width: 100%;
+  height: $custom-file-height;
+  margin: 0;
+  opacity: 0;
+
+  &:focus ~ .custom-file-label {
+    border-color: $custom-file-focus-border-color;
+    box-shadow: $custom-file-focus-box-shadow;
+  }
+
+  &:disabled ~ .custom-file-label {
+    background-color: $custom-file-disabled-bg;
+  }
+
+  @each $lang, $value in $custom-file-text {
+    &:lang(#{$lang}) ~ .custom-file-label::after {
+      content: $value;
+    }
+  }
+
+  ~ .custom-file-label[data-browse]::after {
+    content: attr(data-browse);
+  }
+}
+
+.custom-file-label {
+  position: absolute;
+  top: 0;
+  right: 0;
+  left: 0;
+  z-index: 1;
+  height: $custom-file-height;
+  padding: $custom-file-padding-y $custom-file-padding-x;
+  font-family: $custom-file-font-family;
+  font-weight: $custom-file-font-weight;
+  line-height: $custom-file-line-height;
+  color: $custom-file-color;
+  background-color: $custom-file-bg;
+  border: $custom-file-border-width solid $custom-file-border-color;
+  @include border-radius($custom-file-border-radius);
+  @include box-shadow($custom-file-box-shadow);
+
+  &::after {
+    position: absolute;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    z-index: 3;
+    display: block;
+    height: $custom-file-height-inner;
+    padding: $custom-file-padding-y $custom-file-padding-x;
+    line-height: $custom-file-line-height;
+    color: $custom-file-button-color;
+    content: "Browse";
+    @include gradient-bg($custom-file-button-bg);
+    border-left: inherit;
+    @include border-radius(0 $custom-file-border-radius $custom-file-border-radius 0);
+  }
+}
+
+// Range
+//
+// Style range inputs the same across browsers. Vendor-specific rules for pseudo
+// elements cannot be mixed. As such, there are no shared styles for focus or
+// active states on prefixed selectors.
+
+.custom-range {
+  width: 100%;
+  height: calc(#{$custom-range-thumb-height} + #{$custom-range-thumb-focus-box-shadow-width * 2});
+  padding: 0; // Need to reset padding
+  background-color: transparent;
+  appearance: none;
+
+  &:focus {
+    outline: none;
+
+    // Pseudo-elements must be split across multiple rulesets to have an effect.
+    // No box-shadow() mixin for focus accessibility.
+    &::-webkit-slider-thumb { box-shadow: $custom-range-thumb-focus-box-shadow; }
+    &::-moz-range-thumb     { box-shadow: $custom-range-thumb-focus-box-shadow; }
+    &::-ms-thumb            { box-shadow: $custom-range-thumb-focus-box-shadow; }
+  }
+
+  &::-moz-focus-outer {
+    border: 0;
+  }
+
+  &::-webkit-slider-thumb {
+    width: $custom-range-thumb-width;
+    height: $custom-range-thumb-height;
+    margin-top: ($custom-range-track-height - $custom-range-thumb-height) / 2; // Webkit specific
+    @include gradient-bg($custom-range-thumb-bg);
+    border: $custom-range-thumb-border;
+    @include border-radius($custom-range-thumb-border-radius);
+    @include box-shadow($custom-range-thumb-box-shadow);
+    @include transition($custom-forms-transition);
+    appearance: none;
+
+    &:active {
+      @include gradient-bg($custom-range-thumb-active-bg);
+    }
+  }
+
+  &::-webkit-slider-runnable-track {
+    width: $custom-range-track-width;
+    height: $custom-range-track-height;
+    color: transparent; // Why?
+    cursor: $custom-range-track-cursor;
+    background-color: $custom-range-track-bg;
+    border-color: transparent;
+    @include border-radius($custom-range-track-border-radius);
+    @include box-shadow($custom-range-track-box-shadow);
+  }
+
+  &::-moz-range-thumb {
+    width: $custom-range-thumb-width;
+    height: $custom-range-thumb-height;
+    @include gradient-bg($custom-range-thumb-bg);
+    border: $custom-range-thumb-border;
+    @include border-radius($custom-range-thumb-border-radius);
+    @include box-shadow($custom-range-thumb-box-shadow);
+    @include transition($custom-forms-transition);
+    appearance: none;
+
+    &:active {
+      @include gradient-bg($custom-range-thumb-active-bg);
+    }
+  }
+
+  &::-moz-range-track {
+    width: $custom-range-track-width;
+    height: $custom-range-track-height;
+    color: transparent;
+    cursor: $custom-range-track-cursor;
+    background-color: $custom-range-track-bg;
+    border-color: transparent; // Firefox specific?
+    @include border-radius($custom-range-track-border-radius);
+    @include box-shadow($custom-range-track-box-shadow);
+  }
+
+  &::-ms-thumb {
+    width: $custom-range-thumb-width;
+    height: $custom-range-thumb-height;
+    margin-top: 0; // Edge specific
+    margin-right: $custom-range-thumb-focus-box-shadow-width; // Workaround that overflowed box-shadow is hidden.
+    margin-left: $custom-range-thumb-focus-box-shadow-width;  // Workaround that overflowed box-shadow is hidden.
+    @include gradient-bg($custom-range-thumb-bg);
+    border: $custom-range-thumb-border;
+    @include border-radius($custom-range-thumb-border-radius);
+    @include box-shadow($custom-range-thumb-box-shadow);
+    @include transition($custom-forms-transition);
+    appearance: none;
+
+    &:active {
+      @include gradient-bg($custom-range-thumb-active-bg);
+    }
+  }
+
+  &::-ms-track {
+    width: $custom-range-track-width;
+    height: $custom-range-track-height;
+    color: transparent;
+    cursor: $custom-range-track-cursor;
+    background-color: transparent;
+    border-color: transparent;
+    border-width: $custom-range-thumb-height / 2;
+    @include box-shadow($custom-range-track-box-shadow);
+  }
+
+  &::-ms-fill-lower {
+    background-color: $custom-range-track-bg;
+    @include border-radius($custom-range-track-border-radius);
+  }
+
+  &::-ms-fill-upper {
+    margin-right: 15px; // arbitrary?
+    background-color: $custom-range-track-bg;
+    @include border-radius($custom-range-track-border-radius);
+  }
+
+  &:disabled {
+    &::-webkit-slider-thumb {
+      background-color: $custom-range-thumb-disabled-bg;
+    }
+
+    &::-webkit-slider-runnable-track {
+      cursor: default;
+    }
+
+    &::-moz-range-thumb {
+      background-color: $custom-range-thumb-disabled-bg;
+    }
+
+    &::-moz-range-track {
+      cursor: default;
+    }
+
+    &::-ms-thumb {
+      background-color: $custom-range-thumb-disabled-bg;
+    }
+  }
+}
+
+.custom-control-label::before,
+.custom-file-label,
+.custom-select {
+  @include transition($custom-forms-transition);
+}

example/static/vendor/bootstrap/scss/_dropdown.scss

@@ -0,0 +1,191 @@
+// The dropdown wrapper (`<div>`)
+.dropup,
+.dropright,
+.dropdown,
+.dropleft {
+  position: relative;
+}
+
+.dropdown-toggle {
+  white-space: nowrap;
+
+  // Generate the caret automatically
+  @include caret;
+}
+
+// The dropdown menu
+.dropdown-menu {
+  position: absolute;
+  top: 100%;
+  left: 0;
+  z-index: $zindex-dropdown;
+  display: none; // none by default, but block on "open" of the menu
+  float: left;
+  min-width: $dropdown-min-width;
+  padding: $dropdown-padding-y 0;
+  margin: $dropdown-spacer 0 0; // override default ul
+  @include font-size($dropdown-font-size);
+  color: $dropdown-color;
+  text-align: left; // Ensures proper alignment if parent has it changed (e.g., modal footer)
+  list-style: none;
+  background-color: $dropdown-bg;
+  background-clip: padding-box;
+  border: $dropdown-border-width solid $dropdown-border-color;
+  @include border-radius($dropdown-border-radius);
+  @include box-shadow($dropdown-box-shadow);
+}
+
+@each $breakpoint in map-keys($grid-breakpoints) {
+  @include media-breakpoint-up($breakpoint) {
+    $infix: breakpoint-infix($breakpoint, $grid-breakpoints);
+
+    .dropdown-menu#{$infix}-left {
+      right: auto;
+      left: 0;
+    }
+
+    .dropdown-menu#{$infix}-right {
+      right: 0;
+      left: auto;
+    }
+  }
+}
+
+// Allow for dropdowns to go bottom up (aka, dropup-menu)
+// Just add .dropup after the standard .dropdown class and you're set.
+.dropup {
+  .dropdown-menu {
+    top: auto;
+    bottom: 100%;
+    margin-top: 0;
+    margin-bottom: $dropdown-spacer;
+  }
+
+  .dropdown-toggle {
+    @include caret(up);
+  }
+}
+
+.dropright {
+  .dropdown-menu {
+    top: 0;
+    right: auto;
+    left: 100%;
+    margin-top: 0;
+    margin-left: $dropdown-spacer;
+  }
+
+  .dropdown-toggle {
+    @include caret(right);
+    &::after {
+      vertical-align: 0;
+    }
+  }
+}
+
+.dropleft {
+  .dropdown-menu {
+    top: 0;
+    right: 100%;
+    left: auto;
+    margin-top: 0;
+    margin-right: $dropdown-spacer;
+  }
+
+  .dropdown-toggle {
+    @include caret(left);
+    &::before {
+      vertical-align: 0;
+    }
+  }
+}
+
+// When enabled Popper.js, reset basic dropdown position
+// stylelint-disable-next-line no-duplicate-selectors
+.dropdown-menu {
+  &[x-placement^="top"],
+  &[x-placement^="right"],
+  &[x-placement^="bottom"],
+  &[x-placement^="left"] {
+    right: auto;
+    bottom: auto;
+  }
+}
+
+// Dividers (basically an `<hr>`) within the dropdown
+.dropdown-divider {
+  @include nav-divider($dropdown-divider-bg, $dropdown-divider-margin-y);
+}
+
+// Links, buttons, and more within the dropdown menu
+//
+// `<button>`-specific styles are denoted with `// For <button>s`
+.dropdown-item {
+  display: block;
+  width: 100%; // For `<button>`s
+  padding: $dropdown-item-padding-y $dropdown-item-padding-x;
+  clear: both;
+  font-weight: $font-weight-normal;
+  color: $dropdown-link-color;
+  text-align: inherit; // For `<button>`s
+  white-space: nowrap; // prevent links from randomly breaking onto new lines
+  background-color: transparent; // For `<button>`s
+  border: 0; // For `<button>`s
+
+  // Prevent dropdown overflow if there's no padding
+  // See https://github.com/twbs/bootstrap/pull/27703
+  @if $dropdown-padding-y == 0 {
+    &:first-child {
+      @include border-top-radius($dropdown-inner-border-radius);
+    }
+
+    &:last-child {
+      @include border-bottom-radius($dropdown-inner-border-radius);
+    }
+  }
+
+  @include hover-focus {
+    color: $dropdown-link-hover-color;
+    text-decoration: none;
+    @include gradient-bg($dropdown-link-hover-bg);
+  }
+
+  &.active,
+  &:active {
+    color: $dropdown-link-active-color;
+    text-decoration: none;
+    @include gradient-bg($dropdown-link-active-bg);
+  }
+
+  &.disabled,
+  &:disabled {
+    color: $dropdown-link-disabled-color;
+    pointer-events: none;
+    background-color: transparent;
+    // Remove CSS gradients if they're enabled
+    @if $enable-gradients {
+      background-image: none;
+    }
+  }
+}
+
+.dropdown-menu.show {
+  display: block;
+}
+
+// Dropdown section headers
+.dropdown-header {
+  display: block;
+  padding: $dropdown-padding-y $dropdown-item-padding-x;
+  margin-bottom: 0; // for use with heading elements
+  @include font-size($font-size-sm);
+  color: $dropdown-header-color;
+  white-space: nowrap; // as with > li > a
+}
+
+// Dropdown text
+.dropdown-item-text {
+  display: block;
+  padding: $dropdown-item-padding-y $dropdown-item-padding-x;
+  color: $dropdown-link-color;
+}

example/static/vendor/bootstrap/scss/_forms.scss

@@ -0,0 +1,330 @@
+// stylelint-disable selector-no-qualifying-type
+
+//
+// Textual form controls
+//
+
+.form-control {
+  display: block;
+  width: 100%;
+  height: $input-height;
+  padding: $input-padding-y $input-padding-x;
+  font-family: $input-font-family;
+  @include font-size($input-font-size);
+  font-weight: $input-font-weight;
+  line-height: $input-line-height;
+  color: $input-color;
+  background-color: $input-bg;
+  background-clip: padding-box;
+  border: $input-border-width solid $input-border-color;
+
+  // Note: This has no effect on <select>s in some browsers, due to the limited stylability of `<select>`s in CSS.
+  @include border-radius($input-border-radius, 0);
+
+  @include box-shadow($input-box-shadow);
+  @include transition($input-transition);
+
+  // Unstyle the caret on `<select>`s in IE10+.
+  &::-ms-expand {
+    background-color: transparent;
+    border: 0;
+  }
+
+  // Customize the `:focus` state to imitate native WebKit styles.
+  @include form-control-focus();
+
+  // Placeholder
+  &::placeholder {
+    color: $input-placeholder-color;
+    // Override Firefox's unusual default opacity; see https://github.com/twbs/bootstrap/pull/11526.
+    opacity: 1;
+  }
+
+  // Disabled and read-only inputs
+  //
+  // HTML5 says that controls under a fieldset > legend:first-child won't be
+  // disabled if the fieldset is disabled. Due to implementation difficulty, we
+  // don't honor that edge case; we style them as disabled anyway.
+  &:disabled,
+  &[readonly] {
+    background-color: $input-disabled-bg;
+    // iOS fix for unreadable disabled content; see https://github.com/twbs/bootstrap/issues/11655.
+    opacity: 1;
+  }
+}
+
+select.form-control {
+  &:focus::-ms-value {
+    // Suppress the nested default white text on blue background highlight given to
+    // the selected option text when the (still closed) <select> receives focus
+    // in IE and (under certain conditions) Edge, as it looks bad and cannot be made to
+    // match the appearance of the native widget.
+    // See https://github.com/twbs/bootstrap/issues/19398.
+    color: $input-color;
+    background-color: $input-bg;
+  }
+}
+
+// Make file inputs better match text inputs by forcing them to new lines.
+.form-control-file,
+.form-control-range {
+  display: block;
+  width: 100%;
+}
+
+
+//
+// Labels
+//
+
+// For use with horizontal and inline forms, when you need the label (or legend)
+// text to align with the form controls.
+.col-form-label {
+  padding-top: calc(#{$input-padding-y} + #{$input-border-width});
+  padding-bottom: calc(#{$input-padding-y} + #{$input-border-width});
+  margin-bottom: 0; // Override the `<label>/<legend>` default
+  @include font-size(inherit); // Override the `<legend>` default
+  line-height: $input-line-height;
+}
+
+.col-form-label-lg {
+  padding-top: calc(#{$input-padding-y-lg} + #{$input-border-width});
+  padding-bottom: calc(#{$input-padding-y-lg} + #{$input-border-width});
+  @include font-size($input-font-size-lg);
+  line-height: $input-line-height-lg;
+}
+
+.col-form-label-sm {
+  padding-top: calc(#{$input-padding-y-sm} + #{$input-border-width});
+  padding-bottom: calc(#{$input-padding-y-sm} + #{$input-border-width});
+  @include font-size($input-font-size-sm);
+  line-height: $input-line-height-sm;
+}
+
+
+// Readonly controls as plain text
+//
+// Apply class to a readonly input to make it appear like regular plain
+// text (without any border, background color, focus indicator)
+
+.form-control-plaintext {
+  display: block;
+  width: 100%;
+  padding-top: $input-padding-y;
+  padding-bottom: $input-padding-y;
+  margin-bottom: 0; // match inputs if this class comes on inputs with default margins
+  line-height: $input-line-height;
+  color: $input-plaintext-color;
+  background-color: transparent;
+  border: solid transparent;
+  border-width: $input-border-width 0;
+
+  &.form-control-sm,
+  &.form-control-lg {
+    padding-right: 0;
+    padding-left: 0;
+  }
+}
+
+
+// Form control sizing
+//
+// Build on `.form-control` with modifier classes to decrease or increase the
+// height and font-size of form controls.
+//
+// Repeated in `_input_group.scss` to avoid Sass extend issues.
+
+.form-control-sm {
+  height: $input-height-sm;
+  padding: $input-padding-y-sm $input-padding-x-sm;
+  @include font-size($input-font-size-sm);
+  line-height: $input-line-height-sm;
+  @include border-radius($input-border-radius-sm);
+}
+
+.form-control-lg {
+  height: $input-height-lg;
+  padding: $input-padding-y-lg $input-padding-x-lg;
+  @include font-size($input-font-size-lg);
+  line-height: $input-line-height-lg;
+  @include border-radius($input-border-radius-lg);
+}
+
+// stylelint-disable-next-line no-duplicate-selectors
+select.form-control {
+  &[size],
+  &[multiple] {
+    height: auto;
+  }
+}
+
+textarea.form-control {
+  height: auto;
+}
+
+// Form groups
+//
+// Designed to help with the organization and spacing of vertical forms. For
+// horizontal forms, use the predefined grid classes.
+
+.form-group {
+  margin-bottom: $form-group-margin-bottom;
+}
+
+.form-text {
+  display: block;
+  margin-top: $form-text-margin-top;
+}
+
+
+// Form grid
+//
+// Special replacement for our grid system's `.row` for tighter form layouts.
+
+.form-row {
+  display: flex;
+  flex-wrap: wrap;
+  margin-right: -$form-grid-gutter-width / 2;
+  margin-left: -$form-grid-gutter-width / 2;
+
+  > .col,
+  > [class*="col-"] {
+    padding-right: $form-grid-gutter-width / 2;
+    padding-left: $form-grid-gutter-width / 2;
+  }
+}
+
+
+// Checkboxes and radios
+//
+// Indent the labels to position radios/checkboxes as hanging controls.
+
+.form-check {
+  position: relative;
+  display: block;
+  padding-left: $form-check-input-gutter;
+}
+
+.form-check-input {
+  position: absolute;
+  margin-top: $form-check-input-margin-y;
+  margin-left: -$form-check-input-gutter;
+
+  &:disabled ~ .form-check-label {
+    color: $text-muted;
+  }
+}
+
+.form-check-label {
+  margin-bottom: 0; // Override default `<label>` bottom margin
+}
+
+.form-check-inline {
+  display: inline-flex;
+  align-items: center;
+  padding-left: 0; // Override base .form-check
+  margin-right: $form-check-inline-margin-x;
+
+  // Undo .form-check-input defaults and add some `margin-right`.
+  .form-check-input {
+    position: static;
+    margin-top: 0;
+    margin-right: $form-check-inline-input-margin-x;
+    margin-left: 0;
+  }
+}
+
+
+// Form validation
+//
+// Provide feedback to users when form field values are valid or invalid. Works
+// primarily for client-side validation via scoped `:invalid` and `:valid`
+// pseudo-classes but also includes `.is-invalid` and `.is-valid` classes for
+// server side validation.
+
+@each $state, $data in $form-validation-states {
+  @include form-validation-state($state, map-get($data, color), map-get($data, icon));
+}
+
+// Inline forms
+//
+// Make forms appear inline(-block) by adding the `.form-inline` class. Inline
+// forms begin stacked on extra small (mobile) devices and then go inline when
+// viewports reach <768px.
+//
+// Requires wrapping inputs and labels with `.form-group` for proper display of
+// default HTML form controls and our custom form controls (e.g., input groups).
+
+.form-inline {
+  display: flex;
+  flex-flow: row wrap;
+  align-items: center; // Prevent shorter elements from growing to same height as others (e.g., small buttons growing to normal sized button height)
+
+  // Because we use flex, the initial sizing of checkboxes is collapsed and
+  // doesn't occupy the full-width (which is what we want for xs grid tier),
+  // so we force that here.
+  .form-check {
+    width: 100%;
+  }
+
+  // Kick in the inline
+  @include media-breakpoint-up(sm) {
+    label {
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      margin-bottom: 0;
+    }
+
+    // Inline-block all the things for "inline"
+    .form-group {
+      display: flex;
+      flex: 0 0 auto;
+      flex-flow: row wrap;
+      align-items: center;
+      margin-bottom: 0;
+    }
+
+    // Allow folks to *not* use `.form-group`
+    .form-control {
+      display: inline-block;
+      width: auto; // Prevent labels from stacking above inputs in `.form-group`
+      vertical-align: middle;
+    }
+
+    // Make static controls behave like regular ones
+    .form-control-plaintext {
+      display: inline-block;
+    }
+
+    .input-group,
+    .custom-select {
+      width: auto;
+    }
+
+    // Remove default margin on radios/checkboxes that were used for stacking, and
+    // then undo the floating of radios and checkboxes to match.
+    .form-check {
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      width: auto;
+      padding-left: 0;
+    }
+    .form-check-input {
+      position: relative;
+      flex-shrink: 0;
+      margin-top: 0;
+      margin-right: $form-check-input-margin-x;
+      margin-left: 0;
+    }
+
+    .custom-control {
+      align-items: center;
+      justify-content: center;
+    }
+    .custom-control-label {
+      margin-bottom: 0;
+    }
+  }
+}

example/static/vendor/bootstrap/scss/_functions.scss

@@ -0,0 +1,86 @@
+// Bootstrap functions
+//
+// Utility mixins and functions for evaluating source code across our variables, maps, and mixins.
+
+// Ascending
+// Used to evaluate Sass maps like our grid breakpoints.
+@mixin _assert-ascending($map, $map-name) {
+  $prev-key: null;
+  $prev-num: null;
+  @each $key, $num in $map {
+    @if $prev-num == null or unit($num) == "%" {
+      // Do nothing
+    } @else if not comparable($prev-num, $num) {
+      @warn "Potentially invalid value for #{$map-name}: This map must be in ascending order, but key '#{$key}' has value #{$num} whose unit makes it incomparable to #{$prev-num}, the value of the previous key '#{$prev-key}' !";
+    } @else if $prev-num >= $num {
+      @warn "Invalid value for #{$map-name}: This map must be in ascending order, but key '#{$key}' has value #{$num} which isn't greater than #{$prev-num}, the value of the previous key '#{$prev-key}' !";
+    }
+    $prev-key: $key;
+    $prev-num: $num;
+  }
+}
+
+// Starts at zero
+// Used to ensure the min-width of the lowest breakpoint starts at 0.
+@mixin _assert-starts-at-zero($map, $map-name: "$grid-breakpoints") {
+  $values: map-values($map);
+  $first-value: nth($values, 1);
+  @if $first-value != 0 {
+    @warn "First breakpoint in #{$map-name} must start at 0, but starts at #{$first-value}.";
+  }
+}
+
+// Replace `$search` with `$replace` in `$string`
+// Used on our SVG icon backgrounds for custom forms.
+//
+// @author Hugo Giraudel
+// @param {String} $string - Initial string
+// @param {String} $search - Substring to replace
+// @param {String} $replace ('') - New value
+// @return {String} - Updated string
+@function str-replace($string, $search, $replace: "") {
+  $index: str-index($string, $search);
+
+  @if $index {
+    @return str-slice($string, 1, $index - 1) + $replace + str-replace(str-slice($string, $index + str-length($search)), $search, $replace);
+  }
+
+  @return $string;
+}
+
+// Color contrast
+@function color-yiq($color, $dark: $yiq-text-dark, $light: $yiq-text-light) {
+  $r: red($color);
+  $g: green($color);
+  $b: blue($color);
+
+  $yiq: (($r * 299) + ($g * 587) + ($b * 114)) / 1000;
+
+  @if ($yiq >= $yiq-contrasted-threshold) {
+    @return $dark;
+  } @else {
+    @return $light;
+  }
+}
+
+// Retrieve color Sass maps
+@function color($key: "blue") {
+  @return map-get($colors, $key);
+}
+
+@function theme-color($key: "primary") {
+  @return map-get($theme-colors, $key);
+}
+
+@function gray($key: "100") {
+  @return map-get($grays, $key);
+}
+
+// Request a theme color level
+@function theme-color-level($color-name: "primary", $level: 0) {
+  $color: theme-color($color-name);
+  $color-base: if($level > 0, $black, $white);
+  $level: abs($level);
+
+  @return mix($color-base, $color, $level * $theme-color-interval);
+}

example/static/vendor/bootstrap/scss/_grid.scss

@@ -0,0 +1,52 @@
+// Container widths
+//
+// Set the container width, and override it for fixed navbars in media queries.
+
+@if $enable-grid-classes {
+  .container {
+    @include make-container();
+    @include make-container-max-widths();
+  }
+}
+
+// Fluid container
+//
+// Utilizes the mixin meant for fixed width containers, but with 100% width for
+// fluid, full width layouts.
+
+@if $enable-grid-classes {
+  .container-fluid {
+    @include make-container();
+  }
+}
+
+// Row
+//
+// Rows contain and clear the floats of your columns.
+
+@if $enable-grid-classes {
+  .row {
+    @include make-row();
+  }
+
+  // Remove the negative margin from default .row, then the horizontal padding
+  // from all immediate children columns (to prevent runaway style inheritance).
+  .no-gutters {
+    margin-right: 0;
+    margin-left: 0;
+
+    > .col,
+    > [class*="col-"] {
+      padding-right: 0;
+      padding-left: 0;
+    }
+  }
+}
+
+// Columns
+//
+// Common styles for small and large grid columns
+
+@if $enable-grid-classes {
+  @include make-grid-columns();
+}

example/static/vendor/bootstrap/scss/_images.scss

@@ -0,0 +1,42 @@
+// Responsive images (ensure images don't scale beyond their parents)
+//
+// This is purposefully opt-in via an explicit class rather than being the default for all `<img>`s.
+// We previously tried the "images are responsive by default" approach in Bootstrap v2,
+// and abandoned it in Bootstrap v3 because it breaks lots of third-party widgets (including Google Maps)
+// which weren't expecting the images within themselves to be involuntarily resized.
+// See also https://github.com/twbs/bootstrap/issues/18178
+.img-fluid {
+  @include img-fluid;
+}
+
+
+// Image thumbnails
+.img-thumbnail {
+  padding: $thumbnail-padding;
+  background-color: $thumbnail-bg;
+  border: $thumbnail-border-width solid $thumbnail-border-color;
+  @include border-radius($thumbnail-border-radius);
+  @include box-shadow($thumbnail-box-shadow);
+
+  // Keep them at most 100% wide
+  @include img-fluid;
+}
+
+//
+// Figures
+//
+
+.figure {
+  // Ensures the caption's text aligns with the image.
+  display: inline-block;
+}
+
+.figure-img {
+  margin-bottom: $spacer / 2;
+  line-height: 1;
+}
+
+.figure-caption {
+  @include font-size($figure-caption-font-size);
+  color: $figure-caption-color;
+}

example/static/vendor/bootstrap/scss/_input-group.scss

@@ -0,0 +1,193 @@
+// stylelint-disable selector-no-qualifying-type
+
+//
+// Base styles
+//
+
+.input-group {
+  position: relative;
+  display: flex;
+  flex-wrap: wrap; // For form validation feedback
+  align-items: stretch;
+  width: 100%;
+
+  > .form-control,
+  > .form-control-plaintext,
+  > .custom-select,
+  > .custom-file {
+    position: relative; // For focus state's z-index
+    flex: 1 1 auto;
+    // Add width 1% and flex-basis auto to ensure that button will not wrap out
+    // the column. Applies to IE Edge+ and Firefox. Chrome does not require this.
+    width: 1%;
+    margin-bottom: 0;
+
+    + .form-control,
+    + .custom-select,
+    + .custom-file {
+      margin-left: -$input-border-width;
+    }
+  }
+
+  // Bring the "active" form control to the top of surrounding elements
+  > .form-control:focus,
+  > .custom-select:focus,
+  > .custom-file .custom-file-input:focus ~ .custom-file-label {
+    z-index: 3;
+  }
+
+  // Bring the custom file input above the label
+  > .custom-file .custom-file-input:focus {
+    z-index: 4;
+  }
+
+  > .form-control,
+  > .custom-select {
+    &:not(:last-child) { @include border-right-radius(0); }
+    &:not(:first-child) { @include border-left-radius(0); }
+  }
+
+  // Custom file inputs have more complex markup, thus requiring different
+  // border-radius overrides.
+  > .custom-file {
+    display: flex;
+    align-items: center;
+
+    &:not(:last-child) .custom-file-label,
+    &:not(:last-child) .custom-file-label::after { @include border-right-radius(0); }
+    &:not(:first-child) .custom-file-label { @include border-left-radius(0); }
+  }
+}
+
+
+// Prepend and append
+//
+// While it requires one extra layer of HTML for each, dedicated prepend and
+// append elements allow us to 1) be less clever, 2) simplify our selectors, and
+// 3) support HTML5 form validation.
+
+.input-group-prepend,
+.input-group-append {
+  display: flex;
+
+  // Ensure buttons are always above inputs for more visually pleasing borders.
+  // This isn't needed for `.input-group-text` since it shares the same border-color
+  // as our inputs.
+  .btn {
+    position: relative;
+    z-index: 2;
+
+    &:focus {
+      z-index: 3;
+    }
+  }
+
+  .btn + .btn,
+  .btn + .input-group-text,
+  .input-group-text + .input-group-text,
+  .input-group-text + .btn {
+    margin-left: -$input-border-width;
+  }
+}
+
+.input-group-prepend { margin-right: -$input-border-width; }
+.input-group-append { margin-left: -$input-border-width; }
+
+
+// Textual addons
+//
+// Serves as a catch-all element for any text or radio/checkbox input you wish
+// to prepend or append to an input.
+
+.input-group-text {
+  display: flex;
+  align-items: center;
+  padding: $input-padding-y $input-padding-x;
+  margin-bottom: 0; // Allow use of <label> elements by overriding our default margin-bottom
+  @include font-size($input-font-size); // Match inputs
+  font-weight: $font-weight-normal;
+  line-height: $input-line-height;
+  color: $input-group-addon-color;
+  text-align: center;
+  white-space: nowrap;
+  background-color: $input-group-addon-bg;
+  border: $input-border-width solid $input-group-addon-border-color;
+  @include border-radius($input-border-radius);
+
+  // Nuke default margins from checkboxes and radios to vertically center within.
+  input[type="radio"],
+  input[type="checkbox"] {
+    margin-top: 0;
+  }
+}
+
+
+// Sizing
+//
+// Remix the default form control sizing classes into new ones for easier
+// manipulation.
+
+.input-group-lg > .form-control:not(textarea),
+.input-group-lg > .custom-select {
+  height: $input-height-lg;
+}
+
+.input-group-lg > .form-control,
+.input-group-lg > .custom-select,
+.input-group-lg > .input-group-prepend > .input-group-text,
+.input-group-lg > .input-group-append > .input-group-text,
+.input-group-lg > .input-group-prepend > .btn,
+.input-group-lg > .input-group-append > .btn {
+  padding: $input-padding-y-lg $input-padding-x-lg;
+  @include font-size($input-font-size-lg);
+  line-height: $input-line-height-lg;
+  @include border-radius($input-border-radius-lg);
+}
+
+.input-group-sm > .form-control:not(textarea),
+.input-group-sm > .custom-select {
+  height: $input-height-sm;
+}
+
+.input-group-sm > .form-control,
+.input-group-sm > .custom-select,
+.input-group-sm > .input-group-prepend > .input-group-text,
+.input-group-sm > .input-group-append > .input-group-text,
+.input-group-sm > .input-group-prepend > .btn,
+.input-group-sm > .input-group-append > .btn {
+  padding: $input-padding-y-sm $input-padding-x-sm;
+  @include font-size($input-font-size-sm);
+  line-height: $input-line-height-sm;
+  @include border-radius($input-border-radius-sm);
+}
+
+.input-group-lg > .custom-select,
+.input-group-sm > .custom-select {
+  padding-right: $custom-select-padding-x + $custom-select-indicator-padding;
+}
+
+
+// Prepend and append rounded corners
+//
+// These rulesets must come after the sizing ones to properly override sm and lg
+// border-radius values when extending. They're more specific than we'd like
+// with the `.input-group >` part, but without it, we cannot override the sizing.
+
+
+.input-group > .input-group-prepend > .btn,
+.input-group > .input-group-prepend > .input-group-text,
+.input-group > .input-group-append:not(:last-child) > .btn,
+.input-group > .input-group-append:not(:last-child) > .input-group-text,
+.input-group > .input-group-append:last-child > .btn:not(:last-child):not(.dropdown-toggle),
+.input-group > .input-group-append:last-child > .input-group-text:not(:last-child) {
+  @include border-right-radius(0);
+}
+
+.input-group > .input-group-append > .btn,
+.input-group > .input-group-append > .input-group-text,
+.input-group > .input-group-prepend:not(:first-child) > .btn,
+.input-group > .input-group-prepend:not(:first-child) > .input-group-text,
+.input-group > .input-group-prepend:first-child > .btn:not(:first-child),
+.input-group > .input-group-prepend:first-child > .input-group-text:not(:first-child) {
+  @include border-left-radius(0);
+}

example/static/vendor/bootstrap/scss/_jumbotron.scss

@@ -0,0 +1,17 @@
+.jumbotron {
+  padding: $jumbotron-padding ($jumbotron-padding / 2);
+  margin-bottom: $jumbotron-padding;
+  color: $jumbotron-color;
+  background-color: $jumbotron-bg;
+  @include border-radius($border-radius-lg);
+
+  @include media-breakpoint-up(sm) {
+    padding: ($jumbotron-padding * 2) $jumbotron-padding;
+  }
+}
+
+.jumbotron-fluid {
+  padding-right: 0;
+  padding-left: 0;
+  @include border-radius(0);
+}

example/static/vendor/bootstrap/scss/_list-group.scss

@@ -0,0 +1,149 @@
+// Base class
+//
+// Easily usable on <ul>, <ol>, or <div>.
+
+.list-group {
+  display: flex;
+  flex-direction: column;
+
+  // No need to set list-style: none; since .list-group-item is block level
+  padding-left: 0; // reset padding because ul and ol
+  margin-bottom: 0;
+}
+
+
+// Interactive list items
+//
+// Use anchor or button elements instead of `li`s or `div`s to create interactive
+// list items. Includes an extra `.active` modifier class for selected items.
+
+.list-group-item-action {
+  width: 100%; // For `<button>`s (anchors become 100% by default though)
+  color: $list-group-action-color;
+  text-align: inherit; // For `<button>`s (anchors inherit)
+
+  // Hover state
+  @include hover-focus {
+    z-index: 1; // Place hover/focus items above their siblings for proper border styling
+    color: $list-group-action-hover-color;
+    text-decoration: none;
+    background-color: $list-group-hover-bg;
+  }
+
+  &:active {
+    color: $list-group-action-active-color;
+    background-color: $list-group-action-active-bg;
+  }
+}
+
+
+// Individual list items
+//
+// Use on `li`s or `div`s within the `.list-group` parent.
+
+.list-group-item {
+  position: relative;
+  display: block;
+  padding: $list-group-item-padding-y $list-group-item-padding-x;
+  // Place the border on the list items and negative margin up for better styling
+  margin-bottom: -$list-group-border-width;
+  color: $list-group-color;
+  background-color: $list-group-bg;
+  border: $list-group-border-width solid $list-group-border-color;
+
+  &:first-child {
+    @include border-top-radius($list-group-border-radius);
+  }
+
+  &:last-child {
+    margin-bottom: 0;
+    @include border-bottom-radius($list-group-border-radius);
+  }
+
+  &.disabled,
+  &:disabled {
+    color: $list-group-disabled-color;
+    pointer-events: none;
+    background-color: $list-group-disabled-bg;
+  }
+
+  // Include both here for `<a>`s and `<button>`s
+  &.active {
+    z-index: 2; // Place active items above their siblings for proper border styling
+    color: $list-group-active-color;
+    background-color: $list-group-active-bg;
+    border-color: $list-group-active-border-color;
+  }
+}
+
+
+// Horizontal
+//
+// Change the layout of list group items from vertical (default) to horizontal.
+
+@each $breakpoint in map-keys($grid-breakpoints) {
+  @include media-breakpoint-up($breakpoint) {
+    $infix: breakpoint-infix($breakpoint, $grid-breakpoints);
+
+    .list-group-horizontal#{$infix} {
+      flex-direction: row;
+
+      .list-group-item {
+        margin-right: -$list-group-border-width;
+        margin-bottom: 0;
+
+        &:first-child {
+          @include border-left-radius($list-group-border-radius);
+          @include border-top-right-radius(0);
+        }
+
+        &:last-child {
+          margin-right: 0;
+          @include border-right-radius($list-group-border-radius);
+          @include border-bottom-left-radius(0);
+        }
+      }
+    }
+  }
+}
+
+
+// Flush list items
+//
+// Remove borders and border-radius to keep list group items edge-to-edge. Most
+// useful within other components (e.g., cards).
+
+.list-group-flush {
+  .list-group-item {
+    border-right: 0;
+    border-left: 0;
+    @include border-radius(0);
+
+    &:last-child {
+      margin-bottom: -$list-group-border-width;
+    }
+  }
+
+  &:first-child {
+    .list-group-item:first-child {
+      border-top: 0;
+    }
+  }
+
+  &:last-child {
+    .list-group-item:last-child {
+      margin-bottom: 0;
+      border-bottom: 0;
+    }
+  }
+}
+
+
+// Contextual variants
+//
+// Add modifier classes to change text and background color on individual items.
+// Organizationally, this must come after the `:hover` states.
+
+@each $color, $value in $theme-colors {
+  @include list-group-item-variant($color, theme-color-level($color, -9), theme-color-level($color, 6));
+}

example/static/vendor/bootstrap/scss/_media.scss

@@ -0,0 +1,8 @@
+.media {
+  display: flex;
+  align-items: flex-start;
+}
+
+.media-body {
+  flex: 1;
+}

example/static/vendor/bootstrap/scss/_mixins.scss

@@ -0,0 +1,47 @@
+// Toggles
+//
+// Used in conjunction with global variables to enable certain theme features.
+
+// Vendor
+@import "vendor/rfs";
+
+// Deprecate
+@import "mixins/deprecate";
+
+// Utilities
+@import "mixins/breakpoints";
+@import "mixins/hover";
+@import "mixins/image";
+@import "mixins/badge";
+@import "mixins/resize";
+@import "mixins/screen-reader";
+@import "mixins/size";
+@import "mixins/reset-text";
+@import "mixins/text-emphasis";
+@import "mixins/text-hide";
+@import "mixins/text-truncate";
+@import "mixins/visibility";
+
+// // Components
+@import "mixins/alert";
+@import "mixins/buttons";
+@import "mixins/caret";
+@import "mixins/pagination";
+@import "mixins/lists";
+@import "mixins/list-group";
+@import "mixins/nav-divider";
+@import "mixins/forms";
+@import "mixins/table-row";
+
+// // Skins
+@import "mixins/background-variant";
+@import "mixins/border-radius";
+@import "mixins/box-shadow";
+@import "mixins/gradients";
+@import "mixins/transition";
+
+// // Layout
+@import "mixins/clearfix";
+@import "mixins/grid-framework";
+@import "mixins/grid";
+@import "mixins/float";

example/static/vendor/bootstrap/scss/_modal.scss

@@ -0,0 +1,229 @@
+// .modal-open      - body class for killing the scroll
+// .modal           - container to scroll within
+// .modal-dialog    - positioning shell for the actual modal
+// .modal-content   - actual modal w/ bg and corners and stuff
+
+
+.modal-open {
+  // Kill the scroll on the body
+  overflow: hidden;
+
+  .modal {
+    overflow-x: hidden;
+    overflow-y: auto;
+  }
+}
+
+// Container that the modal scrolls within
+.modal {
+  position: fixed;
+  top: 0;
+  left: 0;
+  z-index: $zindex-modal;
+  display: none;
+  width: 100%;
+  height: 100%;
+  overflow: hidden;
+  // Prevent Chrome on Windows from adding a focus outline. For details, see
+  // https://github.com/twbs/bootstrap/pull/10951.
+  outline: 0;
+  // We deliberately don't use `-webkit-overflow-scrolling: touch;` due to a
+  // gnarly iOS Safari bug: https://bugs.webkit.org/show_bug.cgi?id=158342
+  // See also https://github.com/twbs/bootstrap/issues/17695
+}
+
+// Shell div to position the modal with bottom padding
+.modal-dialog {
+  position: relative;
+  width: auto;
+  margin: $modal-dialog-margin;
+  // allow clicks to pass through for custom click handling to close modal
+  pointer-events: none;
+
+  // When fading in the modal, animate it to slide down
+  .modal.fade & {
+    @include transition($modal-transition);
+    transform: $modal-fade-transform;
+  }
+  .modal.show & {
+    transform: $modal-show-transform;
+  }
+}
+
+.modal-dialog-scrollable {
+  display: flex; // IE10/11
+  max-height: calc(100% - #{$modal-dialog-margin * 2});
+
+  .modal-content {
+    max-height: calc(100vh - #{$modal-dialog-margin * 2}); // IE10/11
+    overflow: hidden;
+  }
+
+  .modal-header,
+  .modal-footer {
+    flex-shrink: 0;
+  }
+
+  .modal-body {
+    overflow-y: auto;
+  }
+}
+
+.modal-dialog-centered {
+  display: flex;
+  align-items: center;
+  min-height: calc(100% - #{$modal-dialog-margin * 2});
+
+  // Ensure `modal-dialog-centered` extends the full height of the view (IE10/11)
+  &::before {
+    display: block; // IE10
+    height: calc(100vh - #{$modal-dialog-margin * 2});
+    content: "";
+  }
+
+  // Ensure `.modal-body` shows scrollbar (IE10/11)
+  &.modal-dialog-scrollable {
+    flex-direction: column;
+    justify-content: center;
+    height: 100%;
+
+    .modal-content {
+      max-height: none;
+    }
+
+    &::before {
+      content: none;
+    }
+  }
+}
+
+// Actual modal
+.modal-content {
+  position: relative;
+  display: flex;
+  flex-direction: column;
+  width: 100%; // Ensure `.modal-content` extends the full width of the parent `.modal-dialog`
+  // counteract the pointer-events: none; in the .modal-dialog
+  color: $modal-content-color;
+  pointer-events: auto;
+  background-color: $modal-content-bg;
+  background-clip: padding-box;
+  border: $modal-content-border-width solid $modal-content-border-color;
+  @include border-radius($modal-content-border-radius);
+  @include box-shadow($modal-content-box-shadow-xs);
+  // Remove focus outline from opened modal
+  outline: 0;
+}
+
+// Modal background
+.modal-backdrop {
+  position: fixed;
+  top: 0;
+  left: 0;
+  z-index: $zindex-modal-backdrop;
+  width: 100vw;
+  height: 100vh;
+  background-color: $modal-backdrop-bg;
+
+  // Fade for backdrop
+  &.fade { opacity: 0; }
+  &.show { opacity: $modal-backdrop-opacity; }
+}
+
+// Modal header
+// Top section of the modal w/ title and dismiss
+.modal-header {
+  display: flex;
+  align-items: flex-start; // so the close btn always stays on the upper right corner
+  justify-content: space-between; // Put modal header elements (title and dismiss) on opposite ends
+  padding: $modal-header-padding;
+  border-bottom: $modal-header-border-width solid $modal-header-border-color;
+  @include border-top-radius($modal-content-border-radius);
+
+  .close {
+    padding: $modal-header-padding;
+    // auto on the left force icon to the right even when there is no .modal-title
+    margin: (-$modal-header-padding-y) (-$modal-header-padding-x) (-$modal-header-padding-y) auto;
+  }
+}
+
+// Title text within header
+.modal-title {
+  margin-bottom: 0;
+  line-height: $modal-title-line-height;
+}
+
+// Modal body
+// Where all modal content resides (sibling of .modal-header and .modal-footer)
+.modal-body {
+  position: relative;
+  // Enable `flex-grow: 1` so that the body take up as much space as possible
+  // when should there be a fixed height on `.modal-dialog`.
+  flex: 1 1 auto;
+  padding: $modal-inner-padding;
+}
+
+// Footer (for actions)
+.modal-footer {
+  display: flex;
+  align-items: center; // vertically center
+  justify-content: flex-end; // Right align buttons with flex property because text-align doesn't work on flex items
+  padding: $modal-inner-padding;
+  border-top: $modal-footer-border-width solid $modal-footer-border-color;
+  @include border-bottom-radius($modal-content-border-radius);
+
+  // Easily place margin between footer elements
+  > :not(:first-child) { margin-left: .25rem; }
+  > :not(:last-child) { margin-right: .25rem; }
+}
+
+// Measure scrollbar width for padding body during modal show/hide
+.modal-scrollbar-measure {
+  position: absolute;
+  top: -9999px;
+  width: 50px;
+  height: 50px;
+  overflow: scroll;
+}
+
+// Scale up the modal
+@include media-breakpoint-up(sm) {
+  // Automatically set modal's width for larger viewports
+  .modal-dialog {
+    max-width: $modal-md;
+    margin: $modal-dialog-margin-y-sm-up auto;
+  }
+
+  .modal-dialog-scrollable {
+    max-height: calc(100% - #{$modal-dialog-margin-y-sm-up * 2});
+
+    .modal-content {
+      max-height: calc(100vh - #{$modal-dialog-margin-y-sm-up * 2});
+    }
+  }
+
+  .modal-dialog-centered {
+    min-height: calc(100% - #{$modal-dialog-margin-y-sm-up * 2});
+
+    &::before {
+      height: calc(100vh - #{$modal-dialog-margin-y-sm-up * 2});
+    }
+  }
+
+  .modal-content {
+    @include box-shadow($modal-content-box-shadow-sm-up);
+  }
+
+  .modal-sm { max-width: $modal-sm; }
+}
+
+@include media-breakpoint-up(lg) {
+  .modal-lg,
+  .modal-xl {
+    max-width: $modal-lg;
+  }
+}
+
+@include media-breakpoint-up(xl) {
+  .modal-xl { max-width: $modal-xl; }
+}

example/static/vendor/bootstrap/scss/_nav.scss

@@ -0,0 +1,120 @@
+// Base class
+//
+// Kickstart any navigation component with a set of style resets. Works with
+// `<nav>`s or `<ul>`s.
+
+.nav {
+  display: flex;
+  flex-wrap: wrap;
+  padding-left: 0;
+  margin-bottom: 0;
+  list-style: none;
+}
+
+.nav-link {
+  display: block;
+  padding: $nav-link-padding-y $nav-link-padding-x;
+
+  @include hover-focus {
+    text-decoration: none;
+  }
+
+  // Disabled state lightens text
+  &.disabled {
+    color: $nav-link-disabled-color;
+    pointer-events: none;
+    cursor: default;
+  }
+}
+
+//
+// Tabs
+//
+
+.nav-tabs {
+  border-bottom: $nav-tabs-border-width solid $nav-tabs-border-color;
+
+  .nav-item {
+    margin-bottom: -$nav-tabs-border-width;
+  }
+
+  .nav-link {
+    border: $nav-tabs-border-width solid transparent;
+    @include border-top-radius($nav-tabs-border-radius);
+
+    @include hover-focus {
+      border-color: $nav-tabs-link-hover-border-color;
+    }
+
+    &.disabled {
+      color: $nav-link-disabled-color;
+      background-color: transparent;
+      border-color: transparent;
+    }
+  }
+
+  .nav-link.active,
+  .nav-item.show .nav-link {
+    color: $nav-tabs-link-active-color;
+    background-color: $nav-tabs-link-active-bg;
+    border-color: $nav-tabs-link-active-border-color;
+  }
+
+  .dropdown-menu {
+    // Make dropdown border overlap tab border
+    margin-top: -$nav-tabs-border-width;
+    // Remove the top rounded corners here since there is a hard edge above the menu
+    @include border-top-radius(0);
+  }
+}
+
+
+//
+// Pills
+//
+
+.nav-pills {
+  .nav-link {
+    @include border-radius($nav-pills-border-radius);
+  }
+
+  .nav-link.active,
+  .show > .nav-link {
+    color: $nav-pills-link-active-color;
+    background-color: $nav-pills-link-active-bg;
+  }
+}
+
+
+//
+// Justified variants
+//
+
+.nav-fill {
+  .nav-item {
+    flex: 1 1 auto;
+    text-align: center;
+  }
+}
+
+.nav-justified {
+  .nav-item {
+    flex-basis: 0;
+    flex-grow: 1;
+    text-align: center;
+  }
+}
+
+
+// Tabbable tabs
+//
+// Hide tabbable panes to start, show them when `.active`
+
+.tab-content {
+  > .tab-pane {
+    display: none;
+  }
+  > .active {
+    display: block;
+  }
+}

example/static/vendor/bootstrap/scss/_navbar.scss

@@ -0,0 +1,294 @@
+// Contents
+//
+// Navbar
+// Navbar brand
+// Navbar nav
+// Navbar text
+// Navbar divider
+// Responsive navbar
+// Navbar position
+// Navbar themes
+
+
+// Navbar
+//
+// Provide a static navbar from which we expand to create full-width, fixed, and
+// other navbar variations.
+
+.navbar {
+  position: relative;
+  display: flex;
+  flex-wrap: wrap; // allow us to do the line break for collapsing content
+  align-items: center;
+  justify-content: space-between; // space out brand from logo
+  padding: $navbar-padding-y $navbar-padding-x;
+
+  // Because flex properties aren't inherited, we need to redeclare these first
+  // few properties so that content nested within behave properly.
+  > .container,
+  > .container-fluid {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    justify-content: space-between;
+  }
+}
+
+
+// Navbar brand
+//
+// Used for brand, project, or site names.
+
+.navbar-brand {
+  display: inline-block;
+  padding-top: $navbar-brand-padding-y;
+  padding-bottom: $navbar-brand-padding-y;
+  margin-right: $navbar-padding-x;
+  @include font-size($navbar-brand-font-size);
+  line-height: inherit;
+  white-space: nowrap;
+
+  @include hover-focus {
+    text-decoration: none;
+  }
+}
+
+
+// Navbar nav
+//
+// Custom navbar navigation (doesn't require `.nav`, but does make use of `.nav-link`).
+
+.navbar-nav {
+  display: flex;
+  flex-direction: column; // cannot use `inherit` to get the `.navbar`s value
+  padding-left: 0;
+  margin-bottom: 0;
+  list-style: none;
+
+  .nav-link {
+    padding-right: 0;
+    padding-left: 0;
+  }
+
+  .dropdown-menu {
+    position: static;
+    float: none;
+  }
+}
+
+
+// Navbar text
+//
+//
+
+.navbar-text {
+  display: inline-block;
+  padding-top: $nav-link-padding-y;
+  padding-bottom: $nav-link-padding-y;
+}
+
+
+// Responsive navbar
+//
+// Custom styles for responsive collapsing and toggling of navbar contents.
+// Powered by the collapse Bootstrap JavaScript plugin.
+
+// When collapsed, prevent the toggleable navbar contents from appearing in
+// the default flexbox row orientation. Requires the use of `flex-wrap: wrap`
+// on the `.navbar` parent.
+.navbar-collapse {
+  flex-basis: 100%;
+  flex-grow: 1;
+  // For always expanded or extra full navbars, ensure content aligns itself
+  // properly vertically. Can be easily overridden with flex utilities.
+  align-items: center;
+}
+
+// Button for toggling the navbar when in its collapsed state
+.navbar-toggler {
+  padding: $navbar-toggler-padding-y $navbar-toggler-padding-x;
+  @include font-size($navbar-toggler-font-size);
+  line-height: 1;
+  background-color: transparent; // remove default button style
+  border: $border-width solid transparent; // remove default button style
+  @include border-radius($navbar-toggler-border-radius);
+
+  @include hover-focus {
+    text-decoration: none;
+  }
+}
+
+// Keep as a separate element so folks can easily override it with another icon
+// or image file as needed.
+.navbar-toggler-icon {
+  display: inline-block;
+  width: 1.5em;
+  height: 1.5em;
+  vertical-align: middle;
+  content: "";
+  background: no-repeat center center;
+  background-size: 100% 100%;
+}
+
+// Generate series of `.navbar-expand-*` responsive classes for configuring
+// where your navbar collapses.
+.navbar-expand {
+  @each $breakpoint in map-keys($grid-breakpoints) {
+    $next: breakpoint-next($breakpoint, $grid-breakpoints);
+    $infix: breakpoint-infix($next, $grid-breakpoints);
+
+    &#{$infix} {
+      @include media-breakpoint-down($breakpoint) {
+        > .container,
+        > .container-fluid {
+          padding-right: 0;
+          padding-left: 0;
+        }
+      }
+
+      @include media-breakpoint-up($next) {
+        flex-flow: row nowrap;
+        justify-content: flex-start;
+
+        .navbar-nav {
+          flex-direction: row;
+
+          .dropdown-menu {
+            position: absolute;
+          }
+
+          .nav-link {
+            padding-right: $navbar-nav-link-padding-x;
+            padding-left: $navbar-nav-link-padding-x;
+          }
+        }
+
+        // For nesting containers, have to redeclare for alignment purposes
+        > .container,
+        > .container-fluid {
+          flex-wrap: nowrap;
+        }
+
+        .navbar-collapse {
+          display: flex !important; // stylelint-disable-line declaration-no-important
+
+          // Changes flex-bases to auto because of an IE10 bug
+          flex-basis: auto;
+        }
+
+        .navbar-toggler {
+          display: none;
+        }
+      }
+    }
+  }
+}
+
+
+// Navbar themes
+//
+// Styles for switching between navbars with light or dark background.
+
+// Dark links against a light background
+.navbar-light {
+  .navbar-brand {
+    color: $navbar-light-brand-color;
+
+    @include hover-focus {
+      color: $navbar-light-brand-hover-color;
+    }
+  }
+
+  .navbar-nav {
+    .nav-link {
+      color: $navbar-light-color;
+
+      @include hover-focus {
+        color: $navbar-light-hover-color;
+      }
+
+      &.disabled {
+        color: $navbar-light-disabled-color;
+      }
+    }
+
+    .show > .nav-link,
+    .active > .nav-link,
+    .nav-link.show,
+    .nav-link.active {
+      color: $navbar-light-active-color;
+    }
+  }
+
+  .navbar-toggler {
+    color: $navbar-light-color;
+    border-color: $navbar-light-toggler-border-color;
+  }
+
+  .navbar-toggler-icon {
+    background-image: $navbar-light-toggler-icon-bg;
+  }
+
+  .navbar-text {
+    color: $navbar-light-color;
+    a {
+      color: $navbar-light-active-color;
+
+      @include hover-focus {
+        color: $navbar-light-active-color;
+      }
+    }
+  }
+}
+
+// White links against a dark background
+.navbar-dark {
+  .navbar-brand {
+    color: $navbar-dark-brand-color;
+
+    @include hover-focus {
+      color: $navbar-dark-brand-hover-color;
+    }
+  }
+
+  .navbar-nav {
+    .nav-link {
+      color: $navbar-dark-color;
+
+      @include hover-focus {
+        color: $navbar-dark-hover-color;
+      }
+
+      &.disabled {
+        color: $navbar-dark-disabled-color;
+      }
+    }
+
+    .show > .nav-link,
+    .active > .nav-link,
+    .nav-link.show,
+    .nav-link.active {
+      color: $navbar-dark-active-color;
+    }
+  }
+
+  .navbar-toggler {
+    color: $navbar-dark-color;
+    border-color: $navbar-dark-toggler-border-color;
+  }
+
+  .navbar-toggler-icon {
+    background-image: $navbar-dark-toggler-icon-bg;
+  }
+
+  .navbar-text {
+    color: $navbar-dark-color;
+    a {
+      color: $navbar-dark-active-color;
+
+      @include hover-focus {
+        color: $navbar-dark-active-color;
+      }
+    }
+  }
+}

example/static/vendor/bootstrap/scss/_pagination.scss

@@ -0,0 +1,73 @@
+.pagination {
+  display: flex;
+  @include list-unstyled();
+  @include border-radius();
+}
+
+.page-link {
+  position: relative;
+  display: block;
+  padding: $pagination-padding-y $pagination-padding-x;
+  margin-left: -$pagination-border-width;
+  line-height: $pagination-line-height;
+  color: $pagination-color;
+  background-color: $pagination-bg;
+  border: $pagination-border-width solid $pagination-border-color;
+
+  &:hover {
+    z-index: 2;
+    color: $pagination-hover-color;
+    text-decoration: none;
+    background-color: $pagination-hover-bg;
+    border-color: $pagination-hover-border-color;
+  }
+
+  &:focus {
+    z-index: 2;
+    outline: $pagination-focus-outline;
+    box-shadow: $pagination-focus-box-shadow;
+  }
+}
+
+.page-item {
+  &:first-child {
+    .page-link {
+      margin-left: 0;
+      @include border-left-radius($border-radius);
+    }
+  }
+  &:last-child {
+    .page-link {
+      @include border-right-radius($border-radius);
+    }
+  }
+
+  &.active .page-link {
+    z-index: 1;
+    color: $pagination-active-color;
+    background-color: $pagination-active-bg;
+    border-color: $pagination-active-border-color;
+  }
+
+  &.disabled .page-link {
+    color: $pagination-disabled-color;
+    pointer-events: none;
+    // Opinionated: remove the "hand" cursor set previously for .page-link
+    cursor: auto;
+    background-color: $pagination-disabled-bg;
+    border-color: $pagination-disabled-border-color;
+  }
+}
+
+
+//
+// Sizing
+//
+
+.pagination-lg {
+  @include pagination-size($pagination-padding-y-lg, $pagination-padding-x-lg, $font-size-lg, $line-height-lg, $border-radius-lg);
+}
+
+.pagination-sm {
+  @include pagination-size($pagination-padding-y-sm, $pagination-padding-x-sm, $font-size-sm, $line-height-sm, $border-radius-sm);
+}

example/static/vendor/bootstrap/scss/_popover.scss

@@ -0,0 +1,171 @@
+.popover {
+  position: absolute;
+  top: 0;
+  left: 0;
+  z-index: $zindex-popover;
+  display: block;
+  max-width: $popover-max-width;
+  // Our parent element can be arbitrary since tooltips are by default inserted as a sibling of their target element.
+  // So reset our font and text properties to avoid inheriting weird values.
+  @include reset-text();
+  @include font-size($popover-font-size);
+  // Allow breaking very long words so they don't overflow the popover's bounds
+  word-wrap: break-word;
+  background-color: $popover-bg;
+  background-clip: padding-box;
+  border: $popover-border-width solid $popover-border-color;
+  @include border-radius($popover-border-radius);
+  @include box-shadow($popover-box-shadow);
+
+  .arrow {
+    position: absolute;
+    display: block;
+    width: $popover-arrow-width;
+    height: $popover-arrow-height;
+    margin: 0 $border-radius-lg;
+
+    &::before,
+    &::after {
+      position: absolute;
+      display: block;
+      content: "";
+      border-color: transparent;
+      border-style: solid;
+    }
+  }
+}
+
+.bs-popover-top {
+  margin-bottom: $popover-arrow-height;
+
+  > .arrow {
+    bottom: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
+
+    &::before {
+      bottom: 0;
+      border-width: $popover-arrow-height ($popover-arrow-width / 2) 0;
+      border-top-color: $popover-arrow-outer-color;
+    }
+
+    &::after {
+      bottom: $popover-border-width;
+      border-width: $popover-arrow-height ($popover-arrow-width / 2) 0;
+      border-top-color: $popover-arrow-color;
+    }
+  }
+}
+
+.bs-popover-right {
+  margin-left: $popover-arrow-height;
+
+  > .arrow {
+    left: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
+    width: $popover-arrow-height;
+    height: $popover-arrow-width;
+    margin: $border-radius-lg 0; // make sure the arrow does not touch the popover's rounded corners
+
+    &::before {
+      left: 0;
+      border-width: ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2) 0;
+      border-right-color: $popover-arrow-outer-color;
+    }
+
+    &::after {
+      left: $popover-border-width;
+      border-width: ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2) 0;
+      border-right-color: $popover-arrow-color;
+    }
+  }
+}
+
+.bs-popover-bottom {
+  margin-top: $popover-arrow-height;
+
+  > .arrow {
+    top: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
+
+    &::before {
+      top: 0;
+      border-width: 0 ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2);
+      border-bottom-color: $popover-arrow-outer-color;
+    }
+
+    &::after {
+      top: $popover-border-width;
+      border-width: 0 ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2);
+      border-bottom-color: $popover-arrow-color;
+    }
+  }
+
+  // This will remove the popover-header's border just below the arrow
+  .popover-header::before {
+    position: absolute;
+    top: 0;
+    left: 50%;
+    display: block;
+    width: $popover-arrow-width;
+    margin-left: -$popover-arrow-width / 2;
+    content: "";
+    border-bottom: $popover-border-width solid $popover-header-bg;
+  }
+}
+
+.bs-popover-left {
+  margin-right: $popover-arrow-height;
+
+  > .arrow {
+    right: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
+    width: $popover-arrow-height;
+    height: $popover-arrow-width;
+    margin: $border-radius-lg 0; // make sure the arrow does not touch the popover's rounded corners
+
+    &::before {
+      right: 0;
+      border-width: ($popover-arrow-width / 2) 0 ($popover-arrow-width / 2) $popover-arrow-height;
+      border-left-color: $popover-arrow-outer-color;
+    }
+
+    &::after {
+      right: $popover-border-width;
+      border-width: ($popover-arrow-width / 2) 0 ($popover-arrow-width / 2) $popover-arrow-height;
+      border-left-color: $popover-arrow-color;
+    }
+  }
+}
+
+.bs-popover-auto {
+  &[x-placement^="top"] {
+    @extend .bs-popover-top;
+  }
+  &[x-placement^="right"] {
+    @extend .bs-popover-right;
+  }
+  &[x-placement^="bottom"] {
+    @extend .bs-popover-bottom;
+  }
+  &[x-placement^="left"] {
+    @extend .bs-popover-left;
+  }
+}
+
+
+// Offset the popover to account for the popover arrow
+.popover-header {
+  padding: $popover-header-padding-y $popover-header-padding-x;
+  margin-bottom: 0; // Reset the default from Reboot
+  @include font-size($font-size-base);
+  color: $popover-header-color;
+  background-color: $popover-header-bg;
+  border-bottom: $popover-border-width solid darken($popover-header-bg, 5%);
+  $offset-border-width: calc(#{$border-radius-lg} - #{$popover-border-width});
+  @include border-top-radius($offset-border-width);
+
+  &:empty {
+    display: none;
+  }
+}
+
+.popover-body {
+  padding: $popover-body-padding-y $popover-body-padding-x;
+  color: $popover-body-color;
+}

example/static/vendor/bootstrap/scss/_print.scss

@@ -0,0 +1,141 @@
+// stylelint-disable declaration-no-important, selector-no-qualifying-type
+
+// Source: https://github.com/h5bp/html5-boilerplate/blob/master/src/css/main.css
+
+// ==========================================================================
+// Print styles.
+// Inlined to avoid the additional HTTP request:
+// https://www.phpied.com/delay-loading-your-print-css/
+// ==========================================================================
+
+@if $enable-print-styles {
+  @media print {
+    *,
+    *::before,
+    *::after {
+      // Bootstrap specific; comment out `color` and `background`
+      //color: $black !important; // Black prints faster
+      text-shadow: none !important;
+      //background: transparent !important;
+      box-shadow: none !important;
+    }
+
+    a {
+      &:not(.btn) {
+        text-decoration: underline;
+      }
+    }
+
+    // Bootstrap specific; comment the following selector out
+    //a[href]::after {
+    //  content: " (" attr(href) ")";
+    //}
+
+    abbr[title]::after {
+      content: " (" attr(title) ")";
+    }
+
+    // Bootstrap specific; comment the following selector out
+    //
+    // Don't show links that are fragment identifiers,
+    // or use the `javascript:` pseudo protocol
+    //
+
+    //a[href^="#"]::after,
+    //a[href^="javascript:"]::after {
+    // content: "";
+    //}
+
+    pre {
+      white-space: pre-wrap !important;
+    }
+    pre,
+    blockquote {
+      border: $border-width solid $gray-500; // Bootstrap custom code; using `$border-width` instead of 1px
+      page-break-inside: avoid;
+    }
+
+    //
+    // Printing Tables:
+    // http://css-discuss.incutio.com/wiki/Printing_Tables
+    //
+
+    thead {
+      display: table-header-group;
+    }
+
+    tr,
+    img {
+      page-break-inside: avoid;
+    }
+
+    p,
+    h2,
+    h3 {
+      orphans: 3;
+      widows: 3;
+    }
+
+    h2,
+    h3 {
+      page-break-after: avoid;
+    }
+
+    // Bootstrap specific changes start
+
+    // Specify a size and min-width to make printing closer across browsers.
+    // We don't set margin here because it breaks `size` in Chrome. We also
+    // don't use `!important` on `size` as it breaks in Chrome.
+    @page {
+      size: $print-page-size;
+    }
+    body {
+      min-width: $print-body-min-width !important;
+    }
+    .container {
+      min-width: $print-body-min-width !important;
+    }
+
+    // Bootstrap components
+    .navbar {
+      display: none;
+    }
+    .badge {
+      border: $border-width solid $black;
+    }
+
+    .table {
+      border-collapse: collapse !important;
+
+      td,
+      th {
+        background-color: $white !important;
+      }
+    }
+
+    .table-bordered {
+      th,
+      td {
+        border: 1px solid $gray-300 !important;
+      }
+    }
+
+    .table-dark {
+      color: inherit;
+
+      th,
+      td,
+      thead th,
+      tbody + tbody {
+        border-color: $table-border-color;
+      }
+    }
+
+    .table .thead-dark th {
+      color: inherit;
+      border-color: $table-border-color;
+    }
+
+    // Bootstrap specific changes end
+  }
+}

example/static/vendor/bootstrap/scss/_progress.scss

@@ -0,0 +1,43 @@
+// Disable animation if transitions are disabled
+@if $enable-transitions {
+  @keyframes progress-bar-stripes {
+    from { background-position: $progress-height 0; }
+    to { background-position: 0 0; }
+  }
+}
+
+.progress {
+  display: flex;
+  height: $progress-height;
+  overflow: hidden; // force rounded corners by cropping it
+  @include font-size($progress-font-size);
+  background-color: $progress-bg;
+  @include border-radius($progress-border-radius);
+  @include box-shadow($progress-box-shadow);
+}
+
+.progress-bar {
+  display: flex;
+  flex-direction: column;
+  justify-content: center;
+  color: $progress-bar-color;
+  text-align: center;
+  white-space: nowrap;
+  background-color: $progress-bar-bg;
+  @include transition($progress-bar-transition);
+}
+
+.progress-bar-striped {
+  @include gradient-striped();
+  background-size: $progress-height $progress-height;
+}
+
+@if $enable-transitions {
+  .progress-bar-animated {
+    animation: progress-bar-stripes $progress-bar-animation-timing;
+
+    @media (prefers-reduced-motion: reduce) {
+      animation: none;
+    }
+  }
+}

example/static/vendor/bootstrap/scss/_reboot.scss

@@ -0,0 +1,483 @@
+// stylelint-disable at-rule-no-vendor-prefix, declaration-no-important, selector-no-qualifying-type, property-no-vendor-prefix
+
+// Reboot
+//
+// Normalization of HTML elements, manually forked from Normalize.css to remove
+// styles targeting irrelevant browsers while applying new styles.
+//
+// Normalize is licensed MIT. https://github.com/necolas/normalize.css
+
+
+// Document
+//
+// 1. Change from `box-sizing: content-box` so that `width` is not affected by `padding` or `border`.
+// 2. Change the default font family in all browsers.
+// 3. Correct the line height in all browsers.
+// 4. Prevent adjustments of font size after orientation changes in IE on Windows Phone and in iOS.
+// 5. Change the default tap highlight to be completely transparent in iOS.
+
+*,
+*::before,
+*::after {
+  box-sizing: border-box; // 1
+}
+
+html {
+  font-family: sans-serif; // 2
+  line-height: 1.15; // 3
+  -webkit-text-size-adjust: 100%; // 4
+  -webkit-tap-highlight-color: rgba($black, 0); // 5
+}
+
+// Shim for "new" HTML5 structural elements to display correctly (IE10, older browsers)
+// TODO: remove in v5
+// stylelint-disable-next-line selector-list-comma-newline-after
+article, aside, figcaption, figure, footer, header, hgroup, main, nav, section {
+  display: block;
+}
+
+// Body
+//
+// 1. Remove the margin in all browsers.
+// 2. As a best practice, apply a default `background-color`.
+// 3. Set an explicit initial text-align value so that we can later use
+//    the `inherit` value on things like `<th>` elements.
+
+body {
+  margin: 0; // 1
+  font-family: $font-family-base;
+  @include font-size($font-size-base);
+  font-weight: $font-weight-base;
+  line-height: $line-height-base;
+  color: $body-color;
+  text-align: left; // 3
+  background-color: $body-bg; // 2
+}
+
+// Suppress the focus outline on elements that cannot be accessed via keyboard.
+// This prevents an unwanted focus outline from appearing around elements that
+// might still respond to pointer events.
+//
+// Credit: https://github.com/suitcss/base
+[tabindex="-1"]:focus {
+  outline: 0 !important;
+}
+
+
+// Content grouping
+//
+// 1. Add the correct box sizing in Firefox.
+// 2. Show the overflow in Edge and IE.
+
+hr {
+  box-sizing: content-box; // 1
+  height: 0; // 1
+  overflow: visible; // 2
+}
+
+
+//
+// Typography
+//
+
+// Remove top margins from headings
+//
+// By default, `<h1>`-`<h6>` all receive top and bottom margins. We nuke the top
+// margin for easier control within type scales as it avoids margin collapsing.
+// stylelint-disable-next-line selector-list-comma-newline-after
+h1, h2, h3, h4, h5, h6 {
+  margin-top: 0;
+  margin-bottom: $headings-margin-bottom;
+}
+
+// Reset margins on paragraphs
+//
+// Similarly, the top margin on `<p>`s get reset. However, we also reset the
+// bottom margin to use `rem` units instead of `em`.
+p {
+  margin-top: 0;
+  margin-bottom: $paragraph-margin-bottom;
+}
+
+// Abbreviations
+//
+// 1. Duplicate behavior to the data-* attribute for our tooltip plugin
+// 2. Add the correct text decoration in Chrome, Edge, IE, Opera, and Safari.
+// 3. Add explicit cursor to indicate changed behavior.
+// 4. Remove the bottom border in Firefox 39-.
+// 5. Prevent the text-decoration to be skipped.
+
+abbr[title],
+abbr[data-original-title] { // 1
+  text-decoration: underline; // 2
+  text-decoration: underline dotted; // 2
+  cursor: help; // 3
+  border-bottom: 0; // 4
+  text-decoration-skip-ink: none; // 5
+}
+
+address {
+  margin-bottom: 1rem;
+  font-style: normal;
+  line-height: inherit;
+}
+
+ol,
+ul,
+dl {
+  margin-top: 0;
+  margin-bottom: 1rem;
+}
+
+ol ol,
+ul ul,
+ol ul,
+ul ol {
+  margin-bottom: 0;
+}
+
+dt {
+  font-weight: $dt-font-weight;
+}
+
+dd {
+  margin-bottom: .5rem;
+  margin-left: 0; // Undo browser default
+}
+
+blockquote {
+  margin: 0 0 1rem;
+}
+
+b,
+strong {
+  font-weight: $font-weight-bolder; // Add the correct font weight in Chrome, Edge, and Safari
+}
+
+small {
+  @include font-size(80%); // Add the correct font size in all browsers
+}
+
+//
+// Prevent `sub` and `sup` elements from affecting the line height in
+// all browsers.
+//
+
+sub,
+sup {
+  position: relative;
+  @include font-size(75%);
+  line-height: 0;
+  vertical-align: baseline;
+}
+
+sub { bottom: -.25em; }
+sup { top: -.5em; }
+
+
+//
+// Links
+//
+
+a {
+  color: $link-color;
+  text-decoration: $link-decoration;
+  background-color: transparent; // Remove the gray background on active links in IE 10.
+
+  @include hover {
+    color: $link-hover-color;
+    text-decoration: $link-hover-decoration;
+  }
+}
+
+// And undo these styles for placeholder links/named anchors (without href)
+// which have not been made explicitly keyboard-focusable (without tabindex).
+// It would be more straightforward to just use a[href] in previous block, but that
+// causes specificity issues in many other styles that are too complex to fix.
+// See https://github.com/twbs/bootstrap/issues/19402
+
+a:not([href]):not([tabindex]) {
+  color: inherit;
+  text-decoration: none;
+
+  @include hover-focus {
+    color: inherit;
+    text-decoration: none;
+  }
+
+  &:focus {
+    outline: 0;
+  }
+}
+
+
+//
+// Code
+//
+
+pre,
+code,
+kbd,
+samp {
+  font-family: $font-family-monospace;
+  @include font-size(1em); // Correct the odd `em` font sizing in all browsers.
+}
+
+pre {
+  // Remove browser default top margin
+  margin-top: 0;
+  // Reset browser default of `1em` to use `rem`s
+  margin-bottom: 1rem;
+  // Don't allow content to break outside
+  overflow: auto;
+}
+
+
+//
+// Figures
+//
+
+figure {
+  // Apply a consistent margin strategy (matches our type styles).
+  margin: 0 0 1rem;
+}
+
+
+//
+// Images and content
+//
+
+img {
+  vertical-align: middle;
+  border-style: none; // Remove the border on images inside links in IE 10-.
+}
+
+svg {
+  // Workaround for the SVG overflow bug in IE10/11 is still required.
+  // See https://github.com/twbs/bootstrap/issues/26878
+  overflow: hidden;
+  vertical-align: middle;
+}
+
+
+//
+// Tables
+//
+
+table {
+  border-collapse: collapse; // Prevent double borders
+}
+
+caption {
+  padding-top: $table-cell-padding;
+  padding-bottom: $table-cell-padding;
+  color: $table-caption-color;
+  text-align: left;
+  caption-side: bottom;
+}
+
+th {
+  // Matches default `<td>` alignment by inheriting from the `<body>`, or the
+  // closest parent with a set `text-align`.
+  text-align: inherit;
+}
+
+
+//
+// Forms
+//
+
+label {
+  // Allow labels to use `margin` for spacing.
+  display: inline-block;
+  margin-bottom: $label-margin-bottom;
+}
+
+// Remove the default `border-radius` that macOS Chrome adds.
+//
+// Details at https://github.com/twbs/bootstrap/issues/24093
+button {
+  // stylelint-disable-next-line property-blacklist
+  border-radius: 0;
+}
+
+// Work around a Firefox/IE bug where the transparent `button` background
+// results in a loss of the default `button` focus styles.
+//
+// Credit: https://github.com/suitcss/base/
+button:focus {
+  outline: 1px dotted;
+  outline: 5px auto -webkit-focus-ring-color;
+}
+
+input,
+button,
+select,
+optgroup,
+textarea {
+  margin: 0; // Remove the margin in Firefox and Safari
+  font-family: inherit;
+  @include font-size(inherit);
+  line-height: inherit;
+}
+
+button,
+input {
+  overflow: visible; // Show the overflow in Edge
+}
+
+button,
+select {
+  text-transform: none; // Remove the inheritance of text transform in Firefox
+}
+
+// Remove the inheritance of word-wrap in Safari.
+//
+// Details at https://github.com/twbs/bootstrap/issues/24990
+select {
+  word-wrap: normal;
+}
+
+
+// 1. Prevent a WebKit bug where (2) destroys native `audio` and `video`
+//    controls in Android 4.
+// 2. Correct the inability to style clickable types in iOS and Safari.
+button,
+[type="button"], // 1
+[type="reset"],
+[type="submit"] {
+  -webkit-appearance: button; // 2
+}
+
+// Opinionated: add "hand" cursor to non-disabled button elements.
+@if $enable-pointer-cursor-for-buttons {
+  button,
+  [type="button"],
+  [type="reset"],
+  [type="submit"] {
+    &:not(:disabled) {
+      cursor: pointer;
+    }
+  }
+}
+
+// Remove inner border and padding from Firefox, but don't restore the outline like Normalize.
+button::-moz-focus-inner,
+[type="button"]::-moz-focus-inner,
+[type="reset"]::-moz-focus-inner,
+[type="submit"]::-moz-focus-inner {
+  padding: 0;
+  border-style: none;
+}
+
+input[type="radio"],
+input[type="checkbox"] {
+  box-sizing: border-box; // 1. Add the correct box sizing in IE 10-
+  padding: 0; // 2. Remove the padding in IE 10-
+}
+
+
+input[type="date"],
+input[type="time"],
+input[type="datetime-local"],
+input[type="month"] {
+  // Remove the default appearance of temporal inputs to avoid a Mobile Safari
+  // bug where setting a custom line-height prevents text from being vertically
+  // centered within the input.
+  // See https://bugs.webkit.org/show_bug.cgi?id=139848
+  // and https://github.com/twbs/bootstrap/issues/11266
+  -webkit-appearance: listbox;
+}
+
+textarea {
+  overflow: auto; // Remove the default vertical scrollbar in IE.
+  // Textareas should really only resize vertically so they don't break their (horizontal) containers.
+  resize: vertical;
+}
+
+fieldset {
+  // Browsers set a default `min-width: min-content;` on fieldsets,
+  // unlike e.g. `<div>`s, which have `min-width: 0;` by default.
+  // So we reset that to ensure fieldsets behave more like a standard block element.
+  // See https://github.com/twbs/bootstrap/issues/12359
+  // and https://html.spec.whatwg.org/multipage/#the-fieldset-and-legend-elements
+  min-width: 0;
+  // Reset the default outline behavior of fieldsets so they don't affect page layout.
+  padding: 0;
+  margin: 0;
+  border: 0;
+}
+
+// 1. Correct the text wrapping in Edge and IE.
+// 2. Correct the color inheritance from `fieldset` elements in IE.
+legend {
+  display: block;
+  width: 100%;
+  max-width: 100%; // 1
+  padding: 0;
+  margin-bottom: .5rem;
+  @include font-size(1.5rem);
+  line-height: inherit;
+  color: inherit; // 2
+  white-space: normal; // 1
+}
+
+progress {
+  vertical-align: baseline; // Add the correct vertical alignment in Chrome, Firefox, and Opera.
+}
+
+// Correct the cursor style of increment and decrement buttons in Chrome.
+[type="number"]::-webkit-inner-spin-button,
+[type="number"]::-webkit-outer-spin-button {
+  height: auto;
+}
+
+[type="search"] {
+  // This overrides the extra rounded corners on search inputs in iOS so that our
+  // `.form-control` class can properly style them. Note that this cannot simply
+  // be added to `.form-control` as it's not specific enough. For details, see
+  // https://github.com/twbs/bootstrap/issues/11586.
+  outline-offset: -2px; // 2. Correct the outline style in Safari.
+  -webkit-appearance: none;
+}
+
+//
+// Remove the inner padding in Chrome and Safari on macOS.
+//
+
+[type="search"]::-webkit-search-decoration {
+  -webkit-appearance: none;
+}
+
+//
+// 1. Correct the inability to style clickable types in iOS and Safari.
+// 2. Change font properties to `inherit` in Safari.
+//
+
+::-webkit-file-upload-button {
+  font: inherit; // 2
+  -webkit-appearance: button; // 1
+}
+
+//
+// Correct element displays
+//
+
+output {
+  display: inline-block;
+}
+
+summary {
+  display: list-item; // Add the correct display in all browsers
+  cursor: pointer;
+}
+
+template {
+  display: none; // Add the correct display in IE
+}
+
+// Always hide an element with the `hidden` HTML attribute (from PureCSS).
+// Needed for proper display in IE 10-.
+[hidden] {
+  display: none !important;
+}

example/static/vendor/bootstrap/scss/_root.scss

@@ -0,0 +1,19 @@
+:root {
+  // Custom variable values only support SassScript inside `#{}`.
+  @each $color, $value in $colors {
+    --#{$color}: #{$value};
+  }
+
+  @each $color, $value in $theme-colors {
+    --#{$color}: #{$value};
+  }
+
+  @each $bp, $value in $grid-breakpoints {
+    --breakpoint-#{$bp}: #{$value};
+  }
+
+  // Use `inspect` for lists so that quoted items keep the quotes.
+  // See https://github.com/sass/sass/issues/2383#issuecomment-336349172
+  --font-family-sans-serif: #{inspect($font-family-sans-serif)};
+  --font-family-monospace: #{inspect($font-family-monospace)};
+}

example/static/vendor/bootstrap/scss/_spinners.scss

@@ -0,0 +1,55 @@
+//
+// Rotating border
+//
+
+@keyframes spinner-border {
+  to { transform: rotate(360deg); }
+}
+
+.spinner-border {
+  display: inline-block;
+  width: $spinner-width;
+  height: $spinner-height;
+  vertical-align: text-bottom;
+  border: $spinner-border-width solid currentColor;
+  border-right-color: transparent;
+  // stylelint-disable-next-line property-blacklist
+  border-radius: 50%;
+  animation: spinner-border .75s linear infinite;
+}
+
+.spinner-border-sm {
+  width: $spinner-width-sm;
+  height: $spinner-height-sm;
+  border-width: $spinner-border-width-sm;
+}
+
+//
+// Growing circle
+//
+
+@keyframes spinner-grow {
+  0% {
+    transform: scale(0);
+  }
+  50% {
+    opacity: 1;
+  }
+}
+
+.spinner-grow {
+  display: inline-block;
+  width: $spinner-width;
+  height: $spinner-height;
+  vertical-align: text-bottom;
+  background-color: currentColor;
+  // stylelint-disable-next-line property-blacklist
+  border-radius: 50%;
+  opacity: 0;
+  animation: spinner-grow .75s linear infinite;
+}
+
+.spinner-grow-sm {
+  width: $spinner-width-sm;
+  height: $spinner-height-sm;
+}

example/static/vendor/bootstrap/scss/_tables.scss

@@ -0,0 +1,185 @@
+//
+// Basic Bootstrap table
+//
+
+.table {
+  width: 100%;
+  margin-bottom: $spacer;
+  color: $table-color;
+  background-color: $table-bg; // Reset for nesting within parents with `background-color`.
+
+  th,
+  td {
+    padding: $table-cell-padding;
+    vertical-align: top;
+    border-top: $table-border-width solid $table-border-color;
+  }
+
+  thead th {
+    vertical-align: bottom;
+    border-bottom: (2 * $table-border-width) solid $table-border-color;
+  }
+
+  tbody + tbody {
+    border-top: (2 * $table-border-width) solid $table-border-color;
+  }
+}
+
+
+//
+// Condensed table w/ half padding
+//
+
+.table-sm {
+  th,
+  td {
+    padding: $table-cell-padding-sm;
+  }
+}
+
+
+// Border versions
+//
+// Add or remove borders all around the table and between all the columns.
+
+.table-bordered {
+  border: $table-border-width solid $table-border-color;
+
+  th,
+  td {
+    border: $table-border-width solid $table-border-color;
+  }
+
+  thead {
+    th,
+    td {
+      border-bottom-width: 2 * $table-border-width;
+    }
+  }
+}
+
+.table-borderless {
+  th,
+  td,
+  thead th,
+  tbody + tbody {
+    border: 0;
+  }
+}
+
+// Zebra-striping
+//
+// Default zebra-stripe styles (alternating gray and transparent backgrounds)
+
+.table-striped {
+  tbody tr:nth-of-type(#{$table-striped-order}) {
+    background-color: $table-accent-bg;
+  }
+}
+
+
+// Hover effect
+//
+// Placed here since it has to come after the potential zebra striping
+
+.table-hover {
+  tbody tr {
+    @include hover {
+      color: $table-hover-color;
+      background-color: $table-hover-bg;
+    }
+  }
+}
+
+
+// Table backgrounds
+//
+// Exact selectors below required to override `.table-striped` and prevent
+// inheritance to nested tables.
+
+@each $color, $value in $theme-colors {
+  @include table-row-variant($color, theme-color-level($color, $table-bg-level), theme-color-level($color, $table-border-level));
+}
+
+@include table-row-variant(active, $table-active-bg);
+
+
+// Dark styles
+//
+// Same table markup, but inverted color scheme: dark background and light text.
+
+// stylelint-disable-next-line no-duplicate-selectors
+.table {
+  .thead-dark {
+    th {
+      color: $table-dark-color;
+      background-color: $table-dark-bg;
+      border-color: $table-dark-border-color;
+    }
+  }
+
+  .thead-light {
+    th {
+      color: $table-head-color;
+      background-color: $table-head-bg;
+      border-color: $table-border-color;
+    }
+  }
+}
+
+.table-dark {
+  color: $table-dark-color;
+  background-color: $table-dark-bg;
+
+  th,
+  td,
+  thead th {
+    border-color: $table-dark-border-color;
+  }
+
+  &.table-bordered {
+    border: 0;
+  }
+
+  &.table-striped {
+    tbody tr:nth-of-type(odd) {
+      background-color: $table-dark-accent-bg;
+    }
+  }
+
+  &.table-hover {
+    tbody tr {
+      @include hover {
+        color: $table-dark-hover-color;
+        background-color: $table-dark-hover-bg;
+      }
+    }
+  }
+}
+
+
+// Responsive tables
+//
+// Generate series of `.table-responsive-*` classes for configuring the screen
+// size of where your table will overflow.
+
+.table-responsive {
+  @each $breakpoint in map-keys($grid-breakpoints) {
+    $next: breakpoint-next($breakpoint, $grid-breakpoints);
+    $infix: breakpoint-infix($next, $grid-breakpoints);
+
+    &#{$infix} {
+      @include media-breakpoint-down($breakpoint) {
+        display: block;
+        width: 100%;
+        overflow-x: auto;
+        -webkit-overflow-scrolling: touch;
+
+        // Prevent double border on horizontal scroll due to use of `display: block;`
+        > .table-bordered {
+          border: 0;
+        }
+      }
+    }
+  }
+}

example/static/vendor/bootstrap/scss/_toasts.scss

@@ -0,0 +1,44 @@
+.toast {
+  max-width: $toast-max-width;
+  overflow: hidden; // cheap rounded corners on nested items
+  @include font-size($toast-font-size);
+  color: $toast-color;
+  background-color: $toast-background-color;
+  background-clip: padding-box;
+  border: $toast-border-width solid $toast-border-color;
+  box-shadow: $toast-box-shadow;
+  backdrop-filter: blur(10px);
+  opacity: 0;
+  @include border-radius($toast-border-radius);
+
+  &:not(:last-child) {
+    margin-bottom: $toast-padding-x;
+  }
+
+  &.showing {
+    opacity: 1;
+  }
+
+  &.show {
+    display: block;
+    opacity: 1;
+  }
+
+  &.hide {
+    display: none;
+  }
+}
+
+.toast-header {
+  display: flex;
+  align-items: center;
+  padding: $toast-padding-y $toast-padding-x;
+  color: $toast-header-color;
+  background-color: $toast-header-background-color;
+  background-clip: padding-box;
+  border-bottom: $toast-border-width solid $toast-header-border-color;
+}
+
+.toast-body {
+  padding: $toast-padding-x; // apply to both vertical and horizontal
+}

example/static/vendor/bootstrap/scss/_tooltip.scss

@@ -0,0 +1,115 @@
+// Base class
+.tooltip {
+  position: absolute;
+  z-index: $zindex-tooltip;
+  display: block;
+  margin: $tooltip-margin;
+  // Our parent element can be arbitrary since tooltips are by default inserted as a sibling of their target element.
+  // So reset our font and text properties to avoid inheriting weird values.
+  @include reset-text();
+  @include font-size($tooltip-font-size);
+  // Allow breaking very long words so they don't overflow the tooltip's bounds
+  word-wrap: break-word;
+  opacity: 0;
+
+  &.show { opacity: $tooltip-opacity; }
+
+  .arrow {
+    position: absolute;
+    display: block;
+    width: $tooltip-arrow-width;
+    height: $tooltip-arrow-height;
+
+    &::before {
+      position: absolute;
+      content: "";
+      border-color: transparent;
+      border-style: solid;
+    }
+  }
+}
+
+.bs-tooltip-top {
+  padding: $tooltip-arrow-height 0;
+
+  .arrow {
+    bottom: 0;
+
+    &::before {
+      top: 0;
+      border-width: $tooltip-arrow-height ($tooltip-arrow-width / 2) 0;
+      border-top-color: $tooltip-arrow-color;
+    }
+  }
+}
+
+.bs-tooltip-right {
+  padding: 0 $tooltip-arrow-height;
+
+  .arrow {
+    left: 0;
+    width: $tooltip-arrow-height;
+    height: $tooltip-arrow-width;
+
+    &::before {
+      right: 0;
+      border-width: ($tooltip-arrow-width / 2) $tooltip-arrow-height ($tooltip-arrow-width / 2) 0;
+      border-right-color: $tooltip-arrow-color;
+    }
+  }
+}
+
+.bs-tooltip-bottom {
+  padding: $tooltip-arrow-height 0;
+
+  .arrow {
+    top: 0;
+
+    &::before {
+      bottom: 0;
+      border-width: 0 ($tooltip-arrow-width / 2) $tooltip-arrow-height;
+      border-bottom-color: $tooltip-arrow-color;
+    }
+  }
+}
+
+.bs-tooltip-left {
+  padding: 0 $tooltip-arrow-height;
+
+  .arrow {
+    right: 0;
+    width: $tooltip-arrow-height;
+    height: $tooltip-arrow-width;
+
+    &::before {
+      left: 0;
+      border-width: ($tooltip-arrow-width / 2) 0 ($tooltip-arrow-width / 2) $tooltip-arrow-height;
+      border-left-color: $tooltip-arrow-color;
+    }
+  }
+}
+
+.bs-tooltip-auto {
+  &[x-placement^="top"] {
+    @extend .bs-tooltip-top;
+  }
+  &[x-placement^="right"] {
+    @extend .bs-tooltip-right;
+  }
+  &[x-placement^="bottom"] {
+    @extend .bs-tooltip-bottom;
+  }
+  &[x-placement^="left"] {
+    @extend .bs-tooltip-left;
+  }
+}
+
+// Wrapper for the tooltip content
+.tooltip-inner {
+  max-width: $tooltip-max-width;
+  padding: $tooltip-padding-y $tooltip-padding-x;
+  color: $tooltip-color;
+  text-align: center;
+  background-color: $tooltip-bg;
+  @include border-radius($tooltip-border-radius);
+}

example/static/vendor/bootstrap/scss/_transitions.scss

@@ -0,0 +1,20 @@
+.fade {
+  @include transition($transition-fade);
+
+  &:not(.show) {
+    opacity: 0;
+  }
+}
+
+.collapse {
+  &:not(.show) {
+    display: none;
+  }
+}
+
+.collapsing {
+  position: relative;
+  height: 0;
+  overflow: hidden;
+  @include transition($transition-collapse);
+}

example/static/vendor/bootstrap/scss/_type.scss

@@ -0,0 +1,125 @@
+// stylelint-disable declaration-no-important, selector-list-comma-newline-after
+
+//
+// Headings
+//
+
+h1, h2, h3, h4, h5, h6,
+.h1, .h2, .h3, .h4, .h5, .h6 {
+  margin-bottom: $headings-margin-bottom;
+  font-family: $headings-font-family;
+  font-weight: $headings-font-weight;
+  line-height: $headings-line-height;
+  color: $headings-color;
+}
+
+h1, .h1 { @include font-size($h1-font-size); }
+h2, .h2 { @include font-size($h2-font-size); }
+h3, .h3 { @include font-size($h3-font-size); }
+h4, .h4 { @include font-size($h4-font-size); }
+h5, .h5 { @include font-size($h5-font-size); }
+h6, .h6 { @include font-size($h6-font-size); }
+
+.lead {
+  @include font-size($lead-font-size);
+  font-weight: $lead-font-weight;
+}
+
+// Type display classes
+.display-1 {
+  @include font-size($display1-size);
+  font-weight: $display1-weight;
+  line-height: $display-line-height;
+}
+.display-2 {
+  @include font-size($display2-size);
+  font-weight: $display2-weight;
+  line-height: $display-line-height;
+}
+.display-3 {
+  @include font-size($display3-size);
+  font-weight: $display3-weight;
+  line-height: $display-line-height;
+}
+.display-4 {
+  @include font-size($display4-size);
+  font-weight: $display4-weight;
+  line-height: $display-line-height;
+}
+
+
+//
+// Horizontal rules
+//
+
+hr {
+  margin-top: $hr-margin-y;
+  margin-bottom: $hr-margin-y;
+  border: 0;
+  border-top: $hr-border-width solid $hr-border-color;
+}
+
+
+//
+// Emphasis
+//
+
+small,
+.small {
+  @include font-size($small-font-size);
+  font-weight: $font-weight-normal;
+}
+
+mark,
+.mark {
+  padding: $mark-padding;
+  background-color: $mark-bg;
+}
+
+
+//
+// Lists
+//
+
+.list-unstyled {
+  @include list-unstyled;
+}
+
+// Inline turns list items into inline-block
+.list-inline {
+  @include list-unstyled;
+}
+.list-inline-item {
+  display: inline-block;
+
+  &:not(:last-child) {
+    margin-right: $list-inline-padding;
+  }
+}
+
+
+//
+// Misc
+//
+
+// Builds on `abbr`
+.initialism {
+  @include font-size(90%);
+  text-transform: uppercase;
+}
+
+// Blockquotes
+.blockquote {
+  margin-bottom: $spacer;
+  @include font-size($blockquote-font-size);
+}
+
+.blockquote-footer {
+  display: block;
+  @include font-size($blockquote-small-font-size);
+  color: $blockquote-small-color;
+
+  &::before {
+    content: "\2014\00A0"; // em dash, nbsp
+  }
+}

example/static/vendor/bootstrap/scss/_utilities.scss

@@ -0,0 +1,17 @@
+@import "utilities/align";
+@import "utilities/background";
+@import "utilities/borders";
+@import "utilities/clearfix";
+@import "utilities/display";
+@import "utilities/embed";
+@import "utilities/flex";
+@import "utilities/float";
+@import "utilities/overflow";
+@import "utilities/position";
+@import "utilities/screenreaders";
+@import "utilities/shadows";
+@import "utilities/sizing";
+@import "utilities/stretched-link";
+@import "utilities/spacing";
+@import "utilities/text";
+@import "utilities/visibility";

example/static/vendor/bootstrap/scss/bootstrap-grid.scss

@@ -0,0 +1,29 @@
+/*!
+ * Bootstrap Grid v4.3.1 (https://getbootstrap.com/)
+ * Copyright 2011-2019 The Bootstrap Authors
+ * Copyright 2011-2019 Twitter, Inc.
+ * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
+ */
+
+html {
+  box-sizing: border-box;
+  -ms-overflow-style: scrollbar;
+}
+
+*,
+*::before,
+*::after {
+  box-sizing: inherit;
+}
+
+@import "functions";
+@import "variables";
+
+@import "mixins/breakpoints";
+@import "mixins/grid-framework";
+@import "mixins/grid";
+
+@import "grid";
+@import "utilities/display";
+@import "utilities/flex";
+@import "utilities/spacing";

example/static/vendor/bootstrap/scss/bootstrap-reboot.scss

@@ -0,0 +1,12 @@
+/*!
+ * Bootstrap Reboot v4.3.1 (https://getbootstrap.com/)
+ * Copyright 2011-2019 The Bootstrap Authors
+ * Copyright 2011-2019 Twitter, Inc.
+ * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
+ * Forked from Normalize.css, licensed MIT (https://github.com/necolas/normalize.css/blob/master/LICENSE.md)
+ */
+
+@import "functions";
+@import "variables";
+@import "mixins";
+@import "reboot";

example/static/vendor/bootstrap/scss/bootstrap.scss

@@ -0,0 +1,44 @@
+/*!
+ * Bootstrap v4.3.1 (https://getbootstrap.com/)
+ * Copyright 2011-2019 The Bootstrap Authors
+ * Copyright 2011-2019 Twitter, Inc.
+ * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
+ */
+
+@import "functions";
+@import "variables";
+@import "mixins";
+@import "root";
+@import "reboot";
+@import "type";
+@import "images";
+@import "code";
+@import "grid";
+@import "tables";
+@import "forms";
+@import "buttons";
+@import "transitions";
+@import "dropdown";
+@import "button-group";
+@import "input-group";
+@import "custom-forms";
+@import "nav";
+@import "navbar";
+@import "card";
+@import "breadcrumb";
+@import "pagination";
+@import "badge";
+@import "jumbotron";
+@import "alert";
+@import "progress";
+@import "media";
+@import "list-group";
+@import "close";
+@import "toasts";
+@import "modal";
+@import "tooltip";
+@import "popover";
+@import "carousel";
+@import "spinners";
+@import "utilities";
+@import "print";

example/static/vendor/bootstrap/scss/mixins/_alert.scss

@@ -0,0 +1,13 @@
+@mixin alert-variant($background, $border, $color) {
+  color: $color;
+  @include gradient-bg($background);
+  border-color: $border;
+
+  hr {
+    border-top-color: darken($border, 5%);
+  }
+
+  .alert-link {
+    color: darken($color, 10%);
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_background-variant.scss

@@ -0,0 +1,21 @@
+// stylelint-disable declaration-no-important
+
+// Contextual backgrounds
+
+@mixin bg-variant($parent, $color) {
+  #{$parent} {
+    background-color: $color !important;
+  }
+  a#{$parent},
+  button#{$parent} {
+    @include hover-focus {
+      background-color: darken($color, 10%) !important;
+    }
+  }
+}
+
+@mixin bg-gradient-variant($parent, $color) {
+  #{$parent} {
+    background: $color linear-gradient(180deg, mix($body-bg, $color, 15%), $color) repeat-x !important;
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_badge.scss

@@ -0,0 +1,17 @@
+@mixin badge-variant($bg) {
+  color: color-yiq($bg);
+  background-color: $bg;
+
+  @at-root a#{&} {
+    @include hover-focus {
+      color: color-yiq($bg);
+      background-color: darken($bg, 10%);
+    }
+
+    &:focus,
+    &.focus {
+      outline: 0;
+      box-shadow: 0 0 0 $badge-focus-width rgba($bg, .5);
+    }
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_border-radius.scss

@@ -0,0 +1,63 @@
+// stylelint-disable property-blacklist
+// Single side border-radius
+
+@mixin border-radius($radius: $border-radius, $fallback-border-radius: false) {
+  @if $enable-rounded {
+    border-radius: $radius;
+  }
+  @else if $fallback-border-radius != false {
+    border-radius: $fallback-border-radius;
+  }
+}
+
+@mixin border-top-radius($radius) {
+  @if $enable-rounded {
+    border-top-left-radius: $radius;
+    border-top-right-radius: $radius;
+  }
+}
+
+@mixin border-right-radius($radius) {
+  @if $enable-rounded {
+    border-top-right-radius: $radius;
+    border-bottom-right-radius: $radius;
+  }
+}
+
+@mixin border-bottom-radius($radius) {
+  @if $enable-rounded {
+    border-bottom-right-radius: $radius;
+    border-bottom-left-radius: $radius;
+  }
+}
+
+@mixin border-left-radius($radius) {
+  @if $enable-rounded {
+    border-top-left-radius: $radius;
+    border-bottom-left-radius: $radius;
+  }
+}
+
+@mixin border-top-left-radius($radius) {
+  @if $enable-rounded {
+    border-top-left-radius: $radius;
+  }
+}
+
+@mixin border-top-right-radius($radius) {
+  @if $enable-rounded {
+    border-top-right-radius: $radius;
+  }
+}
+
+@mixin border-bottom-right-radius($radius) {
+  @if $enable-rounded {
+    border-bottom-right-radius: $radius;
+  }
+}
+
+@mixin border-bottom-left-radius($radius) {
+  @if $enable-rounded {
+    border-bottom-left-radius: $radius;
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_box-shadow.scss

@@ -0,0 +1,20 @@
+@mixin box-shadow($shadow...) {
+  @if $enable-shadows {
+    $result: ();
+
+    @if (length($shadow) == 1) {
+      // We can pass `@include box-shadow(none);`
+      $result: $shadow;
+    } @else {
+      // Filter to avoid invalid properties for example `box-shadow: none, 1px 1px black;`
+      @for $i from 1 through length($shadow) {
+        @if nth($shadow, $i) != "none" {
+          $result: append($result, nth($shadow, $i), "comma");
+        }
+      }
+    }
+    @if (length($result) > 0) {
+      box-shadow: $result;
+    }
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_breakpoints.scss

@@ -0,0 +1,123 @@
+// Breakpoint viewport sizes and media queries.
+//
+// Breakpoints are defined as a map of (name: minimum width), order from small to large:
+//
+//    (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px)
+//
+// The map defined in the `$grid-breakpoints` global variable is used as the `$breakpoints` argument by default.
+
+// Name of the next breakpoint, or null for the last breakpoint.
+//
+//    >> breakpoint-next(sm)
+//    md
+//    >> breakpoint-next(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
+//    md
+//    >> breakpoint-next(sm, $breakpoint-names: (xs sm md lg xl))
+//    md
+@function breakpoint-next($name, $breakpoints: $grid-breakpoints, $breakpoint-names: map-keys($breakpoints)) {
+  $n: index($breakpoint-names, $name);
+  @return if($n != null and $n < length($breakpoint-names), nth($breakpoint-names, $n + 1), null);
+}
+
+// Minimum breakpoint width. Null for the smallest (first) breakpoint.
+//
+//    >> breakpoint-min(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
+//    576px
+@function breakpoint-min($name, $breakpoints: $grid-breakpoints) {
+  $min: map-get($breakpoints, $name);
+  @return if($min != 0, $min, null);
+}
+
+// Maximum breakpoint width. Null for the largest (last) breakpoint.
+// The maximum value is calculated as the minimum of the next one less 0.02px
+// to work around the limitations of `min-` and `max-` prefixes and viewports with fractional widths.
+// See https://www.w3.org/TR/mediaqueries-4/#mq-min-max
+// Uses 0.02px rather than 0.01px to work around a current rounding bug in Safari.
+// See https://bugs.webkit.org/show_bug.cgi?id=178261
+//
+//    >> breakpoint-max(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
+//    767.98px
+@function breakpoint-max($name, $breakpoints: $grid-breakpoints) {
+  $next: breakpoint-next($name, $breakpoints);
+  @return if($next, breakpoint-min($next, $breakpoints) - .02, null);
+}
+
+// Returns a blank string if smallest breakpoint, otherwise returns the name with a dash in front.
+// Useful for making responsive utilities.
+//
+//    >> breakpoint-infix(xs, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
+//    ""  (Returns a blank string)
+//    >> breakpoint-infix(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
+//    "-sm"
+@function breakpoint-infix($name, $breakpoints: $grid-breakpoints) {
+  @return if(breakpoint-min($name, $breakpoints) == null, "", "-#{$name}");
+}
+
+// Media of at least the minimum breakpoint width. No query for the smallest breakpoint.
+// Makes the @content apply to the given breakpoint and wider.
+@mixin media-breakpoint-up($name, $breakpoints: $grid-breakpoints) {
+  $min: breakpoint-min($name, $breakpoints);
+  @if $min {
+    @media (min-width: $min) {
+      @content;
+    }
+  } @else {
+    @content;
+  }
+}
+
+// Media of at most the maximum breakpoint width. No query for the largest breakpoint.
+// Makes the @content apply to the given breakpoint and narrower.
+@mixin media-breakpoint-down($name, $breakpoints: $grid-breakpoints) {
+  $max: breakpoint-max($name, $breakpoints);
+  @if $max {
+    @media (max-width: $max) {
+      @content;
+    }
+  } @else {
+    @content;
+  }
+}
+
+// Media that spans multiple breakpoint widths.
+// Makes the @content apply between the min and max breakpoints
+@mixin media-breakpoint-between($lower, $upper, $breakpoints: $grid-breakpoints) {
+  $min: breakpoint-min($lower, $breakpoints);
+  $max: breakpoint-max($upper, $breakpoints);
+
+  @if $min != null and $max != null {
+    @media (min-width: $min) and (max-width: $max) {
+      @content;
+    }
+  } @else if $max == null {
+    @include media-breakpoint-up($lower, $breakpoints) {
+      @content;
+    }
+  } @else if $min == null {
+    @include media-breakpoint-down($upper, $breakpoints) {
+      @content;
+    }
+  }
+}
+
+// Media between the breakpoint's minimum and maximum widths.
+// No minimum for the smallest breakpoint, and no maximum for the largest one.
+// Makes the @content apply only to the given breakpoint, not viewports any wider or narrower.
+@mixin media-breakpoint-only($name, $breakpoints: $grid-breakpoints) {
+  $min: breakpoint-min($name, $breakpoints);
+  $max: breakpoint-max($name, $breakpoints);
+
+  @if $min != null and $max != null {
+    @media (min-width: $min) and (max-width: $max) {
+      @content;
+    }
+  } @else if $max == null {
+    @include media-breakpoint-up($name, $breakpoints) {
+      @content;
+    }
+  } @else if $min == null {
+    @include media-breakpoint-down($name, $breakpoints) {
+      @content;
+    }
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_buttons.scss

@@ -0,0 +1,107 @@
+// Button variants
+//
+// Easily pump out default styles, as well as :hover, :focus, :active,
+// and disabled options for all buttons
+
+@mixin button-variant($background, $border, $hover-background: darken($background, 7.5%), $hover-border: darken($border, 10%), $active-background: darken($background, 10%), $active-border: darken($border, 12.5%)) {
+  color: color-yiq($background);
+  @include gradient-bg($background);
+  border-color: $border;
+  @include box-shadow($btn-box-shadow);
+
+  @include hover {
+    color: color-yiq($hover-background);
+    @include gradient-bg($hover-background);
+    border-color: $hover-border;
+  }
+
+  &:focus,
+  &.focus {
+    // Avoid using mixin so we can pass custom focus shadow properly
+    @if $enable-shadows {
+      box-shadow: $btn-box-shadow, 0 0 0 $btn-focus-width rgba(mix(color-yiq($background), $border, 15%), .5);
+    } @else {
+      box-shadow: 0 0 0 $btn-focus-width rgba(mix(color-yiq($background), $border, 15%), .5);
+    }
+  }
+
+  // Disabled comes first so active can properly restyle
+  &.disabled,
+  &:disabled {
+    color: color-yiq($background);
+    background-color: $background;
+    border-color: $border;
+    // Remove CSS gradients if they're enabled
+    @if $enable-gradients {
+      background-image: none;
+    }
+  }
+
+  &:not(:disabled):not(.disabled):active,
+  &:not(:disabled):not(.disabled).active,
+  .show > &.dropdown-toggle {
+    color: color-yiq($active-background);
+    background-color: $active-background;
+    @if $enable-gradients {
+      background-image: none; // Remove the gradient for the pressed/active state
+    }
+    border-color: $active-border;
+
+    &:focus {
+      // Avoid using mixin so we can pass custom focus shadow properly
+      @if $enable-shadows and $btn-active-box-shadow != none {
+        box-shadow: $btn-active-box-shadow, 0 0 0 $btn-focus-width rgba(mix(color-yiq($background), $border, 15%), .5);
+      } @else {
+        box-shadow: 0 0 0 $btn-focus-width rgba(mix(color-yiq($background), $border, 15%), .5);
+      }
+    }
+  }
+}
+
+@mixin button-outline-variant($color, $color-hover: color-yiq($color), $active-background: $color, $active-border: $color) {
+  color: $color;
+  border-color: $color;
+
+  @include hover {
+    color: $color-hover;
+    background-color: $active-background;
+    border-color: $active-border;
+  }
+
+  &:focus,
+  &.focus {
+    box-shadow: 0 0 0 $btn-focus-width rgba($color, .5);
+  }
+
+  &.disabled,
+  &:disabled {
+    color: $color;
+    background-color: transparent;
+  }
+
+  &:not(:disabled):not(.disabled):active,
+  &:not(:disabled):not(.disabled).active,
+  .show > &.dropdown-toggle {
+    color: color-yiq($active-background);
+    background-color: $active-background;
+    border-color: $active-border;
+
+    &:focus {
+      // Avoid using mixin so we can pass custom focus shadow properly
+      @if $enable-shadows and $btn-active-box-shadow != none {
+        box-shadow: $btn-active-box-shadow, 0 0 0 $btn-focus-width rgba($color, .5);
+      } @else {
+        box-shadow: 0 0 0 $btn-focus-width rgba($color, .5);
+      }
+    }
+  }
+}
+
+// Button sizes
+@mixin button-size($padding-y, $padding-x, $font-size, $line-height, $border-radius) {
+  padding: $padding-y $padding-x;
+  @include font-size($font-size);
+  line-height: $line-height;
+  // Manually declare to provide an override to the browser default
+  @include border-radius($border-radius, 0);
+}

example/static/vendor/bootstrap/scss/mixins/_caret.scss

@@ -0,0 +1,62 @@
+@mixin caret-down {
+  border-top: $caret-width solid;
+  border-right: $caret-width solid transparent;
+  border-bottom: 0;
+  border-left: $caret-width solid transparent;
+}
+
+@mixin caret-up {
+  border-top: 0;
+  border-right: $caret-width solid transparent;
+  border-bottom: $caret-width solid;
+  border-left: $caret-width solid transparent;
+}
+
+@mixin caret-right {
+  border-top: $caret-width solid transparent;
+  border-right: 0;
+  border-bottom: $caret-width solid transparent;
+  border-left: $caret-width solid;
+}
+
+@mixin caret-left {
+  border-top: $caret-width solid transparent;
+  border-right: $caret-width solid;
+  border-bottom: $caret-width solid transparent;
+}
+
+@mixin caret($direction: down) {
+  @if $enable-caret {
+    &::after {
+      display: inline-block;
+      margin-left: $caret-spacing;
+      vertical-align: $caret-vertical-align;
+      content: "";
+      @if $direction == down {
+        @include caret-down;
+      } @else if $direction == up {
+        @include caret-up;
+      } @else if $direction == right {
+        @include caret-right;
+      }
+    }
+
+    @if $direction == left {
+      &::after {
+        display: none;
+      }
+
+      &::before {
+        display: inline-block;
+        margin-right: $caret-spacing;
+        vertical-align: $caret-vertical-align;
+        content: "";
+        @include caret-left;
+      }
+    }
+
+    &:empty::after {
+      margin-left: 0;
+    }
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_clearfix.scss

@@ -0,0 +1,7 @@
+@mixin clearfix() {
+  &::after {
+    display: block;
+    clear: both;
+    content: "";
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_deprecate.scss

@@ -0,0 +1,10 @@
+// Deprecate mixin
+//
+// This mixin can be used to deprecate mixins or functions.
+// `$enable-deprecation-messages` is a global variable, `$ignore-warning` is a variable that can be passed to
+// some deprecated mixins to suppress the warning (for example if the mixin is still be used in the current version of Bootstrap)
+@mixin deprecate($name, $deprecate-version, $remove-version, $ignore-warning: false) {
+  @if ($enable-deprecation-messages != false and $ignore-warning != true) {
+    @warn "#{$name} has been deprecated as of #{$deprecate-version}. It will be removed entirely in #{$remove-version}.";
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_float.scss

@@ -0,0 +1,14 @@
+// stylelint-disable declaration-no-important
+
+@mixin float-left {
+  float: left !important;
+  @include deprecate("The `float-left` mixin", "v4.3.0", "v5");
+}
+@mixin float-right {
+  float: right !important;
+  @include deprecate("The `float-right` mixin", "v4.3.0", "v5");
+}
+@mixin float-none {
+  float: none !important;
+  @include deprecate("The `float-none` mixin", "v4.3.0", "v5");
+}

example/static/vendor/bootstrap/scss/mixins/_forms.scss

@@ -0,0 +1,192 @@
+// Form control focus state
+//
+// Generate a customized focus state and for any input with the specified color,
+// which defaults to the `$input-focus-border-color` variable.
+//
+// We highly encourage you to not customize the default value, but instead use
+// this to tweak colors on an as-needed basis. This aesthetic change is based on
+// WebKit's default styles, but applicable to a wider range of browsers. Its
+// usability and accessibility should be taken into account with any change.
+//
+// Example usage: change the default blue border and shadow to white for better
+// contrast against a dark gray background.
+@mixin form-control-focus() {
+  &:focus {
+    color: $input-focus-color;
+    background-color: $input-focus-bg;
+    border-color: $input-focus-border-color;
+    outline: 0;
+    // Avoid using mixin so we can pass custom focus shadow properly
+    @if $enable-shadows {
+      box-shadow: $input-box-shadow, $input-focus-box-shadow;
+    } @else {
+      box-shadow: $input-focus-box-shadow;
+    }
+  }
+}
+
+
+@mixin form-validation-state($state, $color, $icon) {
+  .#{$state}-feedback {
+    display: none;
+    width: 100%;
+    margin-top: $form-feedback-margin-top;
+    @include font-size($form-feedback-font-size);
+    color: $color;
+  }
+
+  .#{$state}-tooltip {
+    position: absolute;
+    top: 100%;
+    z-index: 5;
+    display: none;
+    max-width: 100%; // Contain to parent when possible
+    padding: $form-feedback-tooltip-padding-y $form-feedback-tooltip-padding-x;
+    margin-top: .1rem;
+    @include font-size($form-feedback-tooltip-font-size);
+    line-height: $form-feedback-tooltip-line-height;
+    color: color-yiq($color);
+    background-color: rgba($color, $form-feedback-tooltip-opacity);
+    @include border-radius($form-feedback-tooltip-border-radius);
+  }
+
+  .form-control {
+    .was-validated &:#{$state},
+    &.is-#{$state} {
+      border-color: $color;
+
+      @if $enable-validation-icons {
+        padding-right: $input-height-inner;
+        background-image: $icon;
+        background-repeat: no-repeat;
+        background-position: center right $input-height-inner-quarter;
+        background-size: $input-height-inner-half $input-height-inner-half;
+      }
+
+      &:focus {
+        border-color: $color;
+        box-shadow: 0 0 0 $input-focus-width rgba($color, .25);
+      }
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip {
+        display: block;
+      }
+    }
+  }
+
+  // stylelint-disable-next-line selector-no-qualifying-type
+  textarea.form-control {
+    .was-validated &:#{$state},
+    &.is-#{$state} {
+      @if $enable-validation-icons {
+        padding-right: $input-height-inner;
+        background-position: top $input-height-inner-quarter right $input-height-inner-quarter;
+      }
+    }
+  }
+
+  .custom-select {
+    .was-validated &:#{$state},
+    &.is-#{$state} {
+      border-color: $color;
+
+      @if $enable-validation-icons {
+        padding-right: $custom-select-feedback-icon-padding-right;
+        background: $custom-select-background, $icon $custom-select-bg no-repeat $custom-select-feedback-icon-position / $custom-select-feedback-icon-size;
+      }
+
+      &:focus {
+        border-color: $color;
+        box-shadow: 0 0 0 $input-focus-width rgba($color, .25);
+      }
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip {
+        display: block;
+      }
+    }
+  }
+
+
+  .form-control-file {
+    .was-validated &:#{$state},
+    &.is-#{$state} {
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip {
+        display: block;
+      }
+    }
+  }
+
+  .form-check-input {
+    .was-validated &:#{$state},
+    &.is-#{$state} {
+      ~ .form-check-label {
+        color: $color;
+      }
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip {
+        display: block;
+      }
+    }
+  }
+
+  .custom-control-input {
+    .was-validated &:#{$state},
+    &.is-#{$state} {
+      ~ .custom-control-label {
+        color: $color;
+
+        &::before {
+          border-color: $color;
+        }
+      }
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip {
+        display: block;
+      }
+
+      &:checked {
+        ~ .custom-control-label::before {
+          border-color: lighten($color, 10%);
+          @include gradient-bg(lighten($color, 10%));
+        }
+      }
+
+      &:focus {
+        ~ .custom-control-label::before {
+          box-shadow: 0 0 0 $input-focus-width rgba($color, .25);
+        }
+
+        &:not(:checked) ~ .custom-control-label::before {
+          border-color: $color;
+        }
+      }
+    }
+  }
+
+  // custom file
+  .custom-file-input {
+    .was-validated &:#{$state},
+    &.is-#{$state} {
+      ~ .custom-file-label {
+        border-color: $color;
+      }
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip {
+        display: block;
+      }
+
+      &:focus {
+        ~ .custom-file-label {
+          border-color: $color;
+          box-shadow: 0 0 0 $input-focus-width rgba($color, .25);
+        }
+      }
+    }
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_gradients.scss

@@ -0,0 +1,45 @@
+// Gradients
+
+@mixin gradient-bg($color) {
+  @if $enable-gradients {
+    background: $color linear-gradient(180deg, mix($body-bg, $color, 15%), $color) repeat-x;
+  } @else {
+    background-color: $color;
+  }
+}
+
+// Horizontal gradient, from left to right
+//
+// Creates two color stops, start and end, by specifying a color and position for each color stop.
+@mixin gradient-x($start-color: $gray-700, $end-color: $gray-800, $start-percent: 0%, $end-percent: 100%) {
+  background-image: linear-gradient(to right, $start-color $start-percent, $end-color $end-percent);
+  background-repeat: repeat-x;
+}
+
+// Vertical gradient, from top to bottom
+//
+// Creates two color stops, start and end, by specifying a color and position for each color stop.
+@mixin gradient-y($start-color: $gray-700, $end-color: $gray-800, $start-percent: 0%, $end-percent: 100%) {
+  background-image: linear-gradient(to bottom, $start-color $start-percent, $end-color $end-percent);
+  background-repeat: repeat-x;
+}
+
+@mixin gradient-directional($start-color: $gray-700, $end-color: $gray-800, $deg: 45deg) {
+  background-image: linear-gradient($deg, $start-color, $end-color);
+  background-repeat: repeat-x;
+}
+@mixin gradient-x-three-colors($start-color: $blue, $mid-color: $purple, $color-stop: 50%, $end-color: $red) {
+  background-image: linear-gradient(to right, $start-color, $mid-color $color-stop, $end-color);
+  background-repeat: no-repeat;
+}
+@mixin gradient-y-three-colors($start-color: $blue, $mid-color: $purple, $color-stop: 50%, $end-color: $red) {
+  background-image: linear-gradient($start-color, $mid-color $color-stop, $end-color);
+  background-repeat: no-repeat;
+}
+@mixin gradient-radial($inner-color: $gray-700, $outer-color: $gray-800) {
+  background-image: radial-gradient(circle, $inner-color, $outer-color);
+  background-repeat: no-repeat;
+}
+@mixin gradient-striped($color: rgba($white, .15), $angle: 45deg) {
+  background-image: linear-gradient($angle, $color 25%, transparent 25%, transparent 50%, $color 50%, $color 75%, transparent 75%, transparent);
+}

example/static/vendor/bootstrap/scss/mixins/_grid-framework.scss

@@ -0,0 +1,66 @@
+// Framework grid generation
+//
+// Used only by Bootstrap to generate the correct number of grid classes given
+// any value of `$grid-columns`.
+
+@mixin make-grid-columns($columns: $grid-columns, $gutter: $grid-gutter-width, $breakpoints: $grid-breakpoints) {
+  // Common properties for all breakpoints
+  %grid-column {
+    position: relative;
+    width: 100%;
+    padding-right: $gutter / 2;
+    padding-left: $gutter / 2;
+  }
+
+  @each $breakpoint in map-keys($breakpoints) {
+    $infix: breakpoint-infix($breakpoint, $breakpoints);
+
+    // Allow columns to stretch full width below their breakpoints
+    @for $i from 1 through $columns {
+      .col#{$infix}-#{$i} {
+        @extend %grid-column;
+      }
+    }
+    .col#{$infix},
+    .col#{$infix}-auto {
+      @extend %grid-column;
+    }
+
+    @include media-breakpoint-up($breakpoint, $breakpoints) {
+      // Provide basic `.col-{bp}` classes for equal-width flexbox columns
+      .col#{$infix} {
+        flex-basis: 0;
+        flex-grow: 1;
+        max-width: 100%;
+      }
+      .col#{$infix}-auto {
+        flex: 0 0 auto;
+        width: auto;
+        max-width: 100%; // Reset earlier grid tiers
+      }
+
+      @for $i from 1 through $columns {
+        .col#{$infix}-#{$i} {
+          @include make-col($i, $columns);
+        }
+      }
+
+      .order#{$infix}-first { order: -1; }
+
+      .order#{$infix}-last { order: $columns + 1; }
+
+      @for $i from 0 through $columns {
+        .order#{$infix}-#{$i} { order: $i; }
+      }
+
+      // `$columns - 1` because offsetting by the width of an entire row isn't possible
+      @for $i from 0 through ($columns - 1) {
+        @if not ($infix == "" and $i == 0) { // Avoid emitting useless .offset-0
+          .offset#{$infix}-#{$i} {
+            @include make-col-offset($i, $columns);
+          }
+        }
+      }
+    }
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_grid.scss

@@ -0,0 +1,51 @@
+/// Grid system
+//
+// Generate semantic grid columns with these mixins.
+
+@mixin make-container($gutter: $grid-gutter-width) {
+  width: 100%;
+  padding-right: $gutter / 2;
+  padding-left: $gutter / 2;
+  margin-right: auto;
+  margin-left: auto;
+}
+
+
+// For each breakpoint, define the maximum width of the container in a media query
+@mixin make-container-max-widths($max-widths: $container-max-widths, $breakpoints: $grid-breakpoints) {
+  @each $breakpoint, $container-max-width in $max-widths {
+    @include media-breakpoint-up($breakpoint, $breakpoints) {
+      max-width: $container-max-width;
+    }
+  }
+}
+
+@mixin make-row($gutter: $grid-gutter-width) {
+  display: flex;
+  flex-wrap: wrap;
+  margin-right: -$gutter / 2;
+  margin-left: -$gutter / 2;
+}
+
+@mixin make-col-ready($gutter: $grid-gutter-width) {
+  position: relative;
+  // Prevent columns from becoming too narrow when at smaller grid tiers by
+  // always setting `width: 100%;`. This works because we use `flex` values
+  // later on to override this initial width.
+  width: 100%;
+  padding-right: $gutter / 2;
+  padding-left: $gutter / 2;
+}
+
+@mixin make-col($size, $columns: $grid-columns) {
+  flex: 0 0 percentage($size / $columns);
+  // Add a `max-width` to ensure content within each column does not blow out
+  // the width of the column. Applies to IE10+ and Firefox. Chrome and Safari
+  // do not appear to require this.
+  max-width: percentage($size / $columns);
+}
+
+@mixin make-col-offset($size, $columns: $grid-columns) {
+  $num: $size / $columns;
+  margin-left: if($num == 0, 0, percentage($num));
+}

example/static/vendor/bootstrap/scss/mixins/_hover.scss

@@ -0,0 +1,37 @@
+// Hover mixin and `$enable-hover-media-query` are deprecated.
+//
+// Originally added during our alphas and maintained during betas, this mixin was
+// designed to prevent `:hover` stickiness on iOS-an issue where hover styles
+// would persist after initial touch.
+//
+// For backward compatibility, we've kept these mixins and updated them to
+// always return their regular pseudo-classes instead of a shimmed media query.
+//
+// Issue: https://github.com/twbs/bootstrap/issues/25195
+
+@mixin hover {
+  &:hover { @content; }
+}
+
+@mixin hover-focus {
+  &:hover,
+  &:focus {
+    @content;
+  }
+}
+
+@mixin plain-hover-focus {
+  &,
+  &:hover,
+  &:focus {
+    @content;
+  }
+}
+
+@mixin hover-focus-active {
+  &:hover,
+  &:focus,
+  &:active {
+    @content;
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_image.scss

@@ -0,0 +1,36 @@
+// Image Mixins
+// - Responsive image
+// - Retina image
+
+
+// Responsive image
+//
+// Keep images from scaling beyond the width of their parents.
+
+@mixin img-fluid {
+  // Part 1: Set a maximum relative to the parent
+  max-width: 100%;
+  // Part 2: Override the height to auto, otherwise images will be stretched
+  // when setting a width and height attribute on the img element.
+  height: auto;
+}
+
+
+// Retina image
+//
+// Short retina mixin for setting background-image and -size.
+
+@mixin img-retina($file-1x, $file-2x, $width-1x, $height-1x) {
+  background-image: url($file-1x);
+
+  // Autoprefixer takes care of adding -webkit-min-device-pixel-ratio and -o-min-device-pixel-ratio,
+  // but doesn't convert dppx=>dpi.
+  // There's no such thing as unprefixed min-device-pixel-ratio since it's nonstandard.
+  // Compatibility info: https://caniuse.com/#feat=css-media-resolution
+  @media only screen and (min-resolution: 192dpi), // IE9-11 don't support dppx
+    only screen and (min-resolution: 2dppx) { // Standardized
+    background-image: url($file-2x);
+    background-size: $width-1x $height-1x;
+  }
+  @include deprecate("`img-retina()`", "v4.3.0", "v5");
+}

example/static/vendor/bootstrap/scss/mixins/_list-group.scss

@@ -0,0 +1,21 @@
+// List Groups
+
+@mixin list-group-item-variant($state, $background, $color) {
+  .list-group-item-#{$state} {
+    color: $color;
+    background-color: $background;
+
+    &.list-group-item-action {
+      @include hover-focus {
+        color: $color;
+        background-color: darken($background, 5%);
+      }
+
+      &.active {
+        color: $white;
+        background-color: $color;
+        border-color: $color;
+      }
+    }
+  }
+}

example/static/vendor/bootstrap/scss/mixins/_lists.scss

@@ -0,0 +1,7 @@
+// Lists
+
+// Unstyled keeps list items block level, just removes default browser padding and list-style
+@mixin list-unstyled {
+  padding-left: 0;
+  list-style: none;
+}