Update to Boostrap 4.3.1

static/src/bootstrap/scss/_alert.scss

@@ -27,7 +27,7 @@
 // Expand the right padding and account for the close button's positioning.
 
 .alert-dismissible {
-  padding-right: ($close-font-size + $alert-padding-x * 2);
+  padding-right: $close-font-size + $alert-padding-x * 2;
 
   // Adjust close link position
   .close {

static/src/bootstrap/scss/_badge.scss

@@ -6,13 +6,20 @@
 .badge {
   display: inline-block;
   padding: $badge-padding-y $badge-padding-x;
-  font-size: $badge-font-size;
+  @include font-size($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 {

static/src/bootstrap/scss/_button-group.scss

@@ -9,7 +9,7 @@
 
   > .btn {
     position: relative;
-    flex: 0 1 auto;
+    flex: 1 1 auto;
 
     // Bring the hover, focused, and "active" buttons to the front to overlay
     // the borders properly
@@ -22,14 +22,6 @@
       z-index: 1;
     }
   }
-
-  // Prevent double borders when buttons are next to each other
-  .btn + .btn,
-  .btn + .btn-group,
-  .btn-group + .btn,
-  .btn-group + .btn-group {
-    margin-left: -$btn-border-width;
-  }
 }
 
 // Optional: Group multiple button groups together for a toolbar
@@ -44,8 +36,10 @@
 }
 
 .btn-group {
-  > .btn:first-child {
+  // Prevent double borders when buttons are next to each other
-    margin-left: 0;
+  > .btn:not(:first-child),
+  > .btn-group:not(:first-child) {
+    margin-left: -$btn-border-width;
   }
 
   // Reset rounded corners
@@ -119,17 +113,14 @@
   align-items: flex-start;
   justify-content: center;
 
-  .btn,
+  > .btn,
-  .btn-group {
+  > .btn-group {
     width: 100%;
   }
 
-  > .btn + .btn,
+  > .btn:not(:first-child),
-  > .btn + .btn-group,
+  > .btn-group:not(:first-child) {
-  > .btn-group + .btn,
-  > .btn-group + .btn-group {
     margin-top: -$btn-border-width;
-    margin-left: 0;
   }
 
   // Reset rounded corners

static/src/bootstrap/scss/_buttons.scss

@@ -6,17 +6,19 @@
 
 .btn {
   display: inline-block;
+  font-family: $btn-font-family;
   font-weight: $btn-font-weight;
+  color: $body-color;
   text-align: center;
-  white-space: nowrap;
   vertical-align: middle;
   user-select: none;
+  background-color: transparent;
   border: $btn-border-width solid transparent;
-  @include button-size($btn-padding-y, $btn-padding-x, $font-size-base, $btn-line-height, $btn-border-radius);
+  @include button-size($btn-padding-y, $btn-padding-x, $btn-font-size, $btn-line-height, $btn-border-radius);
   @include transition($btn-transition);
 
-  // Share hover and focus styles
+  @include hover {
-  @include hover-focus {
+    color: $body-color;
     text-decoration: none;
   }
 
@@ -33,14 +35,8 @@
     @include box-shadow(none);
   }
 
-  // Opinionated: add "hand" cursor to non-disabled .btn elements
-  &:not(:disabled):not(.disabled) {
-    cursor: pointer;
-  }
-
   &:not(:disabled):not(.disabled):active,
   &:not(:disabled):not(.disabled).active {
-    background-image: none;
     @include box-shadow($btn-active-box-shadow);
 
     &:focus {
@@ -81,19 +77,16 @@ fieldset:disabled a.btn {
 .btn-link {
   font-weight: $font-weight-normal;
   color: $link-color;
-  background-color: transparent;
+  text-decoration: $link-decoration;
 
   @include hover {
     color: $link-hover-color;
     text-decoration: $link-hover-decoration;
-    background-color: transparent;
-    border-color: transparent;
   }
 
   &:focus,
   &.focus {
     text-decoration: $link-hover-decoration;
-    border-color: transparent;
     box-shadow: none;
   }
 
@@ -112,11 +105,11 @@ fieldset:disabled a.btn {
 //
 
 .btn-lg {
-  @include button-size($btn-padding-y-lg, $btn-padding-x-lg, $font-size-lg, $btn-line-height-lg, $btn-border-radius-lg);
+  @include button-size($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, $font-size-sm, $btn-line-height-sm, $btn-border-radius-sm);
+  @include button-size($btn-padding-y-sm, $btn-padding-x-sm, $btn-font-size-sm, $btn-line-height-sm, $btn-border-radius-sm);
 }
 
 

static/src/bootstrap/scss/_card.scss

@@ -6,7 +6,7 @@
   position: relative;
   display: flex;
   flex-direction: column;
-  min-width: 0;
+  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;
@@ -36,6 +36,7 @@
   // 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 {
@@ -43,7 +44,7 @@
 }
 
 .card-subtitle {
-  margin-top: -($card-spacer-y / 2);
+  margin-top: -$card-spacer-y / 2;
   margin-bottom: 0;
 }
 
@@ -68,6 +69,7 @@
 .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;
 
@@ -98,15 +100,15 @@
 //
 
 .card-header-tabs {
-  margin-right: -($card-spacer-x / 2);
+  margin-right: -$card-spacer-x / 2;
   margin-bottom: -$card-spacer-y;
-  margin-left: -($card-spacer-x / 2);
+  margin-left: -$card-spacer-x / 2;
   border-bottom: 0;
 }
 
 .card-header-pills {
-  margin-right: -($card-spacer-x / 2);
+  margin-right: -$card-spacer-x / 2;
-  margin-left: -($card-spacer-x / 2);
+  margin-left: -$card-spacer-x / 2;
 }
 
 // Card image
@@ -194,55 +196,35 @@
 
       // Handle rounded corners
       @if $enable-rounded {
-        &:first-child {
+        &: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;
           }
         }
 
-        &:last-child {
+        &: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;
           }
         }
-
-        &:only-child {
-          @include border-radius($card-border-radius);
-
-          .card-img-top,
-          .card-header {
-            @include border-top-radius($card-border-radius);
-          }
-          .card-img-bottom,
-          .card-footer {
-            @include border-bottom-radius($card-border-radius);
-          }
-        }
-
-        &:not(:first-child):not(:last-child):not(:only-child) {
-          @include border-radius(0);
-
-          .card-img-top,
-          .card-img-bottom,
-          .card-header,
-          .card-footer {
-            @include border-radius(0);
-          }
-        }
       }
     }
   }
@@ -277,25 +259,31 @@
 //
 
 .accordion {
-  .card:not(:first-of-type):not(:last-of-type) {
+  > .card {
-    border-bottom: 0;
+    overflow: hidden;
-    border-radius: 0;
-  }
 
-  .card:not(:first-of-type) {
+    &:not(:first-of-type) {
-    .card-header:first-child {
+      .card-header:first-child {
-      border-radius: 0;
+        @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;
     }
   }
-
-  .card:first-of-type {
-    border-bottom: 0;
-    border-bottom-right-radius: 0;
-    border-bottom-left-radius: 0;
-  }
-
-  .card:last-of-type {
-    border-top-left-radius: 0;
-    border-top-right-radius: 0;
-  }
 }

static/src/bootstrap/scss/_carousel.scss

@@ -1,31 +1,39 @@
 // Notes on the classes:
 //
-// 1. The .carousel-item-left and .carousel-item-right is used to indicate where
+// 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.
-// 2. .active.carousel-item is the current slide.
+// 3. .active.carousel-item is the current slide.
-// 3. .active.carousel-item-left and .active.carousel-item-right is the current
+// 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.
-// 4. .carousel-item-next.carousel-item-left and .carousel-item-prev.carousel-item-right
+// 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;
-  align-items: center;
+  float: left;
   width: 100%;
-  @include transition($carousel-transition);
+  margin-right: -100%;
   backface-visibility: hidden;
-  perspective: 1000px;
+  @include transition($carousel-transition);
 }
 
 .carousel-item.active,
@@ -34,37 +42,14 @@
   display: block;
 }
 
-.carousel-item-next,
+.carousel-item-next:not(.carousel-item-left),
-.carousel-item-prev {
-  position: absolute;
-  top: 0;
-}
-
-.carousel-item-next.carousel-item-left,
-.carousel-item-prev.carousel-item-right {
-  transform: translateX(0);
-
-  @supports (transform-style: preserve-3d) {
-    transform: translate3d(0, 0, 0);
-  }
-}
-
-.carousel-item-next,
 .active.carousel-item-right {
   transform: translateX(100%);
-
-  @supports (transform-style: preserve-3d) {
-    transform: translate3d(100%, 0, 0);
-  }
 }
 
-.carousel-item-prev,
+.carousel-item-prev:not(.carousel-item-right),
 .active.carousel-item-left {
   transform: translateX(-100%);
-
-  @supports (transform-style: preserve-3d) {
-    transform: translate3d(-100%, 0, 0);
-  }
 }
 
 
@@ -75,31 +60,22 @@
 .carousel-fade {
   .carousel-item {
     opacity: 0;
-    transition-duration: .6s;
     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);
-
-  .carousel-item-next,
-  .carousel-item-prev,
-  .carousel-item.active,
-  .active.carousel-item-left,
-  .active.carousel-item-prev {
-    transform: translateX(0);
-
-    @supports (transform-style: preserve-3d) {
-      transform: translate3d(0, 0, 0);
-    }
   }
 }
 
@@ -113,6 +89,7 @@
   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
@@ -121,15 +98,14 @@
   color: $carousel-control-color;
   text-align: center;
   opacity: $carousel-control-opacity;
-  // We can't have a transition here because WebKit cancels the carousel
+  @include transition($carousel-control-transition);
-  // animation if you trip this while in the middle of another animation.
 
   // Hover/focus state
   @include hover-focus {
     color: $carousel-control-color;
     text-decoration: none;
     outline: 0;
-    opacity: .9;
+    opacity: $carousel-control-hover-opacity;
   }
 }
 .carousel-control-prev {
@@ -151,8 +127,7 @@
   display: inline-block;
   width: $carousel-control-icon-width;
   height: $carousel-control-icon-width;
-  background: transparent no-repeat center center;
+  background: no-repeat 50% / 100% 100%;
-  background-size: 100% 100%;
 }
 .carousel-control-prev-icon {
   background-image: $carousel-control-prev-icon-bg;
@@ -170,7 +145,7 @@
 .carousel-indicators {
   position: absolute;
   right: 0;
-  bottom: 10px;
+  bottom: 0;
   left: 0;
   z-index: 15;
   display: flex;
@@ -182,7 +157,7 @@
   list-style: none;
 
   li {
-    position: relative;
+    box-sizing: content-box;
     flex: 0 1 auto;
     width: $carousel-indicator-width;
     height: $carousel-indicator-height;
@@ -190,31 +165,17 @@
     margin-left: $carousel-indicator-spacer;
     text-indent: -999px;
     cursor: pointer;
-    background-color: rgba($carousel-indicator-active-bg, .5);
+    background-color: $carousel-indicator-active-bg;
-
+    background-clip: padding-box;
-    // Use pseudo classes to increase the hit area by 10px on top and bottom.
+    // Use transparent borders to increase the hit area by 10px on top and bottom.
-    &::before {
+    border-top: $carousel-indicator-hit-area-height solid transparent;
-      position: absolute;
+    border-bottom: $carousel-indicator-hit-area-height solid transparent;
-      top: -10px;
+    opacity: .5;
-      left: 0;
+    @include transition($carousel-indicator-transition);
-      display: inline-block;
-      width: 100%;
-      height: 10px;
-      content: "";
-    }
-    &::after {
-      position: absolute;
-      bottom: -10px;
-      left: 0;
-      display: inline-block;
-      width: 100%;
-      height: 10px;
-      content: "";
-    }
   }
 
   .active {
-    background-color: $carousel-indicator-active-bg;
+    opacity: 1;
   }
 }
 
@@ -225,9 +186,9 @@
 
 .carousel-caption {
   position: absolute;
-  right: ((100% - $carousel-caption-width) / 2);
+  right: (100% - $carousel-caption-width) / 2;
   bottom: 20px;
-  left: ((100% - $carousel-caption-width) / 2);
+  left: (100% - $carousel-caption-width) / 2;
   z-index: 10;
   padding-top: 20px;
   padding-bottom: 20px;

static/src/bootstrap/scss/_close.scss

@@ -1,21 +1,22 @@
 .close {
   float: right;
-  font-size: $close-font-size;
+  @include font-size($close-font-size);
   font-weight: $close-font-weight;
   line-height: 1;
   color: $close-color;
   text-shadow: $close-text-shadow;
   opacity: .5;
 
-  @include hover-focus {
+  // Override <a>'s hover style
+  @include hover {
     color: $close-color;
     text-decoration: none;
-    opacity: .75;
   }
 
-  // Opinionated: add "hand" cursor to non-disabled .close elements
   &:not(:disabled):not(.disabled) {
-    cursor: pointer;
+    @include hover-focus {
+      opacity: .75;
+    }
   }
 }
 
@@ -24,11 +25,17 @@
 // If you want the anchor version, it requires `href="#"`.
 // See https://developer.mozilla.org/en-US/docs/Web/Events/click#Safari_Mobile
 
-// stylelint-disable property-no-vendor-prefix, selector-no-qualifying-type
+// stylelint-disable-next-line selector-no-qualifying-type
 button.close {
   padding: 0;
   background-color: transparent;
   border: 0;
-  -webkit-appearance: none;
+  appearance: none;
+}
+
+// Future-proof disabling of clicks on `<a>` elements
+
+// stylelint-disable-next-line selector-no-qualifying-type
+a.close.disabled {
+  pointer-events: none;
 }
-// stylelint-enable

static/src/bootstrap/scss/_code.scss

@@ -1,6 +1,6 @@
 // Inline code
 code {
-  font-size: $code-font-size;
+  @include font-size($code-font-size);
   color: $code-color;
   word-break: break-word;
 
@@ -13,7 +13,7 @@ code {
 // User input typically entered via keyboard
 kbd {
   padding: $kbd-padding-y $kbd-padding-x;
-  font-size: $kbd-font-size;
+  @include font-size($kbd-font-size);
   color: $kbd-color;
   background-color: $kbd-bg;
   @include border-radius($border-radius-sm);
@@ -21,7 +21,7 @@ kbd {
 
   kbd {
     padding: 0;
-    font-size: 100%;
+    @include font-size(100%);
     font-weight: $nested-kbd-font-weight;
     @include box-shadow(none);
   }
@@ -30,12 +30,12 @@ kbd {
 // Blocks of code
 pre {
   display: block;
-  font-size: $code-font-size;
+  @include font-size($code-font-size);
   color: $pre-color;
 
   // Account for some code outputs that place code tags in pre tags
   code {
-    font-size: inherit;
+    @include font-size(inherit);
     color: inherit;
     word-break: normal;
   }

static/src/bootstrap/scss/_custom-forms.scss

@@ -10,8 +10,8 @@
 .custom-control {
   position: relative;
   display: block;
-  min-height: (1rem * $line-height-base);
+  min-height: $font-size-base * $line-height-base;
-  padding-left: $custom-control-gutter;
+  padding-left: $custom-control-gutter + $custom-control-indicator-size;
 }
 
 .custom-control-inline {
@@ -26,18 +26,28 @@
 
   &: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
-    box-shadow: $custom-control-indicator-focus-box-shadow;
+    @if $enable-shadows {
+      box-shadow: $input-box-shadow, $input-focus-box-shadow;
+    } @else {
+      box-shadow: $custom-control-indicator-focus-box-shadow;
+    }
   }
 
-  &:active ~ .custom-control-label::before {
+  &: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);
   }
 
@@ -59,34 +69,33 @@
 .custom-control-label {
   position: relative;
   margin-bottom: 0;
+  vertical-align: top;
 
   // Background-color and (when enabled) gradient
   &::before {
     position: absolute;
-    top: (($line-height-base - $custom-control-indicator-size) / 2);
+    top: ($font-size-base * $line-height-base - $custom-control-indicator-size) / 2;
-    left: -$custom-control-gutter;
+    left: -($custom-control-gutter + $custom-control-indicator-size);
     display: block;
     width: $custom-control-indicator-size;
     height: $custom-control-indicator-size;
     pointer-events: none;
     content: "";
-    user-select: none;
     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: (($line-height-base - $custom-control-indicator-size) / 2);
+    top: ($font-size-base * $line-height-base - $custom-control-indicator-size) / 2;
-    left: -$custom-control-gutter;
+    left: -($custom-control-gutter + $custom-control-indicator-size);
     display: block;
     width: $custom-control-indicator-size;
     height: $custom-control-indicator-size;
     content: "";
-    background-repeat: no-repeat;
+    background: no-repeat 50% / #{$custom-control-indicator-bg-size};
-    background-position: center center;
-    background-size: $custom-control-indicator-bg-size;
   }
 }
 
@@ -101,9 +110,6 @@
   }
 
   .custom-control-input:checked ~ .custom-control-label {
-    &::before {
-      @include gradient-bg($custom-control-indicator-checked-bg);
-    }
     &::after {
       background-image: $custom-checkbox-indicator-icon-checked;
     }
@@ -111,6 +117,7 @@
 
   .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);
     }
@@ -135,13 +142,11 @@
 
 .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 {
-    &::before {
-      @include gradient-bg($custom-control-indicator-checked-bg);
-    }
     &::after {
       background-image: $custom-radio-indicator-icon-checked;
     }
@@ -155,6 +160,49 @@
 }
 
 
+// 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
@@ -166,23 +214,27 @@
   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-bg $custom-select-indicator no-repeat right $custom-select-padding-x center;
+  background: $custom-select-background;
-  background-size: $custom-select-bg-size;
+  background-color: $custom-select-bg;
   border: $custom-select-border-width solid $custom-select-border-color;
-  @if $enable-rounded {
+  @include border-radius($custom-select-border-radius, 0);
-    border-radius: $custom-select-border-radius;
+  @include box-shadow($custom-select-box-shadow);
-  } @else {
-    border-radius: 0;
-  }
   appearance: none;
 
   &:focus {
     border-color: $custom-select-focus-border-color;
     outline: 0;
-    box-shadow: $custom-select-focus-box-shadow;
+    @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,
@@ -209,22 +261,24 @@
 
   // Hides the default caret in IE11
   &::-ms-expand {
-    opacity: 0;
+    display: none;
   }
 }
 
 .custom-select-sm {
   height: $custom-select-height-sm;
-  padding-top: $custom-select-padding-y;
+  padding-top: $custom-select-padding-y-sm;
-  padding-bottom: $custom-select-padding-y;
+  padding-bottom: $custom-select-padding-y-sm;
-  font-size: $custom-select-font-size-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;
+  padding-top: $custom-select-padding-y-lg;
-  padding-bottom: $custom-select-padding-y;
+  padding-bottom: $custom-select-padding-y-lg;
-  font-size: $custom-select-font-size-lg;
+  padding-left: $custom-select-padding-x-lg;
+  @include font-size($custom-select-font-size-lg);
 }
 
 
@@ -251,10 +305,10 @@
   &:focus ~ .custom-file-label {
     border-color: $custom-file-focus-border-color;
     box-shadow: $custom-file-focus-box-shadow;
+  }
 
-    &::after {
+  &:disabled ~ .custom-file-label {
-      border-color: $custom-file-focus-border-color;
+    background-color: $custom-file-disabled-bg;
-    }
   }
 
   @each $lang, $value in $custom-file-text {
@@ -262,6 +316,10 @@
       content: $value;
     }
   }
+
+  ~ .custom-file-label[data-browse]::after {
+    content: attr(data-browse);
+  }
 }
 
 .custom-file-label {
@@ -272,6 +330,8 @@
   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;
@@ -292,7 +352,7 @@
     color: $custom-file-button-color;
     content: "Browse";
     @include gradient-bg($custom-file-button-bg);
-    border-left: $custom-file-border-width solid $custom-file-border-color;
+    border-left: inherit;
     @include border-radius(0 $custom-file-border-radius $custom-file-border-radius 0);
   }
 }
@@ -305,12 +365,19 @@
 
 .custom-range {
   width: 100%;
-  padding-left: 0; // Firefox specific
+  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 {
@@ -320,18 +387,14 @@
   &::-webkit-slider-thumb {
     width: $custom-range-thumb-width;
     height: $custom-range-thumb-height;
-    margin-top: -($custom-range-thumb-width * .25); // Webkit specific?
+    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;
 
-    &:focus {
-      outline: none;
-      box-shadow: $custom-range-thumb-focus-box-shadow; // No mixin for focus accessibility
-    }
-
     &:active {
       @include gradient-bg($custom-range-thumb-active-bg);
     }
@@ -355,13 +418,9 @@
     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;
 
-    &:focus {
-      outline: none;
-      box-shadow: $custom-range-thumb-focus-box-shadow; // No mixin for focus accessibility
-    }
-
     &:active {
       @include gradient-bg($custom-range-thumb-active-bg);
     }
@@ -381,17 +440,16 @@
   &::-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;
 
-    &:focus {
-      outline: none;
-      box-shadow: $custom-range-thumb-focus-box-shadow; // No mixin for focus accessibility
-    }
-
     &:active {
       @include gradient-bg($custom-range-thumb-active-bg);
     }
@@ -404,7 +462,7 @@
     cursor: $custom-range-track-cursor;
     background-color: transparent;
     border-color: transparent;
-    border-width: ($custom-range-thumb-height * .5);
+    border-width: $custom-range-thumb-height / 2;
     @include box-shadow($custom-range-track-box-shadow);
   }
 
@@ -418,4 +476,32 @@
     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);
 }

static/src/bootstrap/scss/_dropdown.scss

@@ -7,6 +7,8 @@
 }
 
 .dropdown-toggle {
+  white-space: nowrap;
+
   // Generate the caret automatically
   @include caret;
 }
@@ -22,8 +24,8 @@
   min-width: $dropdown-min-width;
   padding: $dropdown-padding-y 0;
   margin: $dropdown-spacer 0 0; // override default ul
-  font-size: $font-size-base; // Redeclare because nesting can cause inheritance issues
+  @include font-size($dropdown-font-size);
-  color: $body-color;
+  color: $dropdown-color;
   text-align: left; // Ensures proper alignment if parent has it changed (e.g., modal footer)
   list-style: none;
   background-color: $dropdown-bg;
@@ -33,9 +35,20 @@
   @include box-shadow($dropdown-box-shadow);
 }
 
-.dropdown-menu-right {
+@each $breakpoint in map-keys($grid-breakpoints) {
-  right: 0;
+  @include media-breakpoint-up($breakpoint) {
-  left: auto;
+    $infix: breakpoint-infix($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)
@@ -88,7 +101,7 @@
 }
 
 // When enabled Popper.js, reset basic dropdown position
-// stylelint-disable no-duplicate-selectors
+// stylelint-disable-next-line no-duplicate-selectors
 .dropdown-menu {
   &[x-placement^="top"],
   &[x-placement^="right"],
@@ -98,11 +111,10 @@
     bottom: auto;
   }
 }
-// stylelint-enable no-duplicate-selectors
 
 // Dividers (basically an `<hr>`) within the dropdown
 .dropdown-divider {
-  @include nav-divider($dropdown-divider-bg);
+  @include nav-divider($dropdown-divider-bg, $dropdown-divider-margin-y);
 }
 
 // Links, buttons, and more within the dropdown menu
@@ -120,6 +132,18 @@
   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;
@@ -136,6 +160,7 @@
   &.disabled,
   &:disabled {
     color: $dropdown-link-disabled-color;
+    pointer-events: none;
     background-color: transparent;
     // Remove CSS gradients if they're enabled
     @if $enable-gradients {
@@ -153,7 +178,7 @@
   display: block;
   padding: $dropdown-padding-y $dropdown-item-padding-x;
   margin-bottom: 0; // for use with heading elements
-  font-size: $font-size-sm;
+  @include font-size($font-size-sm);
   color: $dropdown-header-color;
   white-space: nowrap; // as with > li > a
 }

static/src/bootstrap/scss/_forms.scss

@@ -7,8 +7,11 @@
 .form-control {
   display: block;
   width: 100%;
+  height: $input-height;
   padding: $input-padding-y $input-padding-x;
-  font-size: $font-size-base;
+  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;
@@ -16,13 +19,7 @@
   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.
-  @if $enable-rounded {
+  @include border-radius($input-border-radius, 0);
-    // Manually use the if/else instead of the mixin to account for iOS override
-    border-radius: $input-border-radius;
-  } @else {
-    // Otherwise undo the iOS default
-    border-radius: 0;
-  }
 
   @include box-shadow($input-box-shadow);
   @include transition($input-transition);
@@ -57,10 +54,6 @@
 }
 
 select.form-control {
-  &:not([size]):not([multiple]) {
-    height: $input-height;
-  }
-
   &:focus::-ms-value {
     // Suppress the nested default white text on blue background highlight given to
     // the selected option text when the (still closed) <select> receives focus
@@ -90,21 +83,21 @@ select.form-control {
   padding-top: calc(#{$input-padding-y} + #{$input-border-width});
   padding-bottom: calc(#{$input-padding-y} + #{$input-border-width});
   margin-bottom: 0; // Override the `<label>/<legend>` default
-  font-size: inherit; // Override the `<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});
-  font-size: $font-size-lg;
+  @include font-size($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});
-  font-size: $font-size-sm;
+  @include font-size($input-font-size-sm);
   line-height: $input-line-height-sm;
 }
 
@@ -139,35 +132,35 @@ select.form-control {
 // Build on `.form-control` with modifier classes to decrease or increase the
 // height and font-size of form controls.
 //
-// The `.form-group-* form-control` variations are sadly duplicated to avoid the
+// Repeated in `_input_group.scss` to avoid Sass extend issues.
-// issue documented in https://github.com/twbs/bootstrap/issues/15074.
 
 .form-control-sm {
+  height: $input-height-sm;
   padding: $input-padding-y-sm $input-padding-x-sm;
-  font-size: $font-size-sm;
+  @include font-size($input-font-size-sm);
   line-height: $input-line-height-sm;
   @include border-radius($input-border-radius-sm);
 }
 
-select.form-control-sm {
-  &:not([size]):not([multiple]) {
-    height: $input-height-sm;
-  }
-}
-
 .form-control-lg {
+  height: $input-height-lg;
   padding: $input-padding-y-lg $input-padding-x-lg;
-  font-size: $font-size-lg;
+  @include font-size($input-font-size-lg);
   line-height: $input-line-height-lg;
   @include border-radius($input-border-radius-lg);
 }
 
-select.form-control-lg {
+// stylelint-disable-next-line no-duplicate-selectors
-  &:not([size]):not([multiple]) {
+select.form-control {
-    height: $input-height-lg;
+  &[size],
+  &[multiple] {
+    height: auto;
   }
 }
 
+textarea.form-control {
+  height: auto;
+}
 
 // Form groups
 //
@@ -191,13 +184,13 @@ select.form-control-lg {
 .form-row {
   display: flex;
   flex-wrap: wrap;
-  margin-right: -5px;
+  margin-right: -$form-grid-gutter-width / 2;
-  margin-left: -5px;
+  margin-left: -$form-grid-gutter-width / 2;
 
   > .col,
   > [class*="col-"] {
-    padding-right: 5px;
+    padding-right: $form-grid-gutter-width / 2;
-    padding-left: 5px;
+    padding-left: $form-grid-gutter-width / 2;
   }
 }
 
@@ -249,8 +242,9 @@ select.form-control-lg {
 // pseudo-classes but also includes `.is-invalid` and `.is-valid` classes for
 // server side validation.
 
-@include form-validation-state("valid", $form-feedback-valid-color);
+@each $state, $data in $form-validation-states {
-@include form-validation-state("invalid", $form-feedback-invalid-color);
+  @include form-validation-state($state, map-get($data, color), map-get($data, icon));
+}
 
 // Inline forms
 //
@@ -319,6 +313,7 @@ select.form-control-lg {
     }
     .form-check-input {
       position: relative;
+      flex-shrink: 0;
       margin-top: 0;
       margin-right: $form-check-input-margin-x;
       margin-left: 0;

static/src/bootstrap/scss/_functions.scss

@@ -1,6 +1,6 @@
 // Bootstrap functions
 //
-// Utility mixins and functions for evalutating source code across our variables, maps, and mixins.
+// Utility mixins and functions for evaluating source code across our variables, maps, and mixins.
 
 // Ascending
 // Used to evaluate Sass maps like our grid breakpoints.
@@ -8,7 +8,7 @@
   $prev-key: null;
   $prev-num: null;
   @each $key, $num in $map {
-    @if $prev-num == null {
+    @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}' !";
@@ -21,12 +21,12 @@
 }
 
 // Starts at zero
-// Another grid mixin that ensures the min-width of the lowest breakpoint starts at 0.
+// Used to ensure the min-width of the lowest breakpoint starts at 0.
-@mixin _assert-starts-at-zero($map) {
+@mixin _assert-starts-at-zero($map, $map-name: "$grid-breakpoints") {
   $values: map-values($map);
   $first-value: nth($values, 1);
   @if $first-value != 0 {
-    @warn "First breakpoint in `$grid-breakpoints` must start at 0, but starts at #{$first-value}.";
+    @warn "First breakpoint in #{$map-name} must start at 0, but starts at #{$first-value}.";
   }
 }
 
@@ -49,7 +49,7 @@
 }
 
 // Color contrast
-@function color-yiq($color) {
+@function color-yiq($color, $dark: $yiq-text-dark, $light: $yiq-text-light) {
   $r: red($color);
   $g: green($color);
   $b: blue($color);
@@ -57,9 +57,9 @@
   $yiq: (($r * 299) + ($g * 587) + ($b * 114)) / 1000;
 
   @if ($yiq >= $yiq-contrasted-threshold) {
-    @return $yiq-text-dark;
+    @return $dark;
   } @else {
-    @return $yiq-text-light;
+    @return $light;
   }
 }
 

static/src/bootstrap/scss/_images.scss

@@ -32,11 +32,11 @@
 }
 
 .figure-img {
-  margin-bottom: ($spacer / 2);
+  margin-bottom: $spacer / 2;
   line-height: 1;
 }
 
 .figure-caption {
-  font-size: $figure-caption-font-size;
+  @include font-size($figure-caption-font-size);
   color: $figure-caption-color;
 }

static/src/bootstrap/scss/_input-group.scss

@@ -12,6 +12,7 @@
   width: 100%;
 
   > .form-control,
+  > .form-control-plaintext,
   > .custom-select,
   > .custom-file {
     position: relative; // For focus state's z-index
@@ -21,11 +22,6 @@
     width: 1%;
     margin-bottom: 0;
 
-    // Bring the "active" form control to the top of surrounding elements
-    &:focus {
-      z-index: 3;
-    }
-
     + .form-control,
     + .custom-select,
     + .custom-file {
@@ -33,6 +29,18 @@
     }
   }
 
+  // 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); }
@@ -68,6 +76,10 @@
   .btn {
     position: relative;
     z-index: 2;
+
+    &:focus {
+      z-index: 3;
+    }
   }
 
   .btn + .btn,
@@ -92,7 +104,7 @@
   align-items: center;
   padding: $input-padding-y $input-padding-x;
   margin-bottom: 0; // Allow use of <label> elements by overriding our default margin-bottom
-  font-size: $font-size-base; // Match inputs
+  @include font-size($input-font-size); // Match inputs
   font-weight: $font-weight-normal;
   line-height: $input-line-height;
   color: $input-group-addon-color;
@@ -115,20 +127,43 @@
 // 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 {
-  @extend .form-control-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);
+}
+
+.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 {
-  @extend .form-control-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);
+}
+
+.input-group-lg > .custom-select,
+.input-group-sm > .custom-select {
+  padding-right: $custom-select-padding-x + $custom-select-indicator-padding;
 }
 
 

static/src/bootstrap/scss/_jumbotron.scss

@@ -1,6 +1,7 @@
 .jumbotron {
   padding: $jumbotron-padding ($jumbotron-padding / 2);
   margin-bottom: $jumbotron-padding;
+  color: $jumbotron-color;
   background-color: $jumbotron-bg;
   @include border-radius($border-radius-lg);
 

static/src/bootstrap/scss/_list-group.scss

@@ -24,6 +24,7 @@
 
   // 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;
@@ -46,6 +47,7 @@
   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;
 
@@ -58,14 +60,10 @@
     @include border-bottom-radius($list-group-border-radius);
   }
 
-  @include hover-focus {
-    z-index: 1; // Place hover/active items above their siblings for proper border styling
-    text-decoration: none;
-  }
-
   &.disabled,
   &:disabled {
     color: $list-group-disabled-color;
+    pointer-events: none;
     background-color: $list-group-disabled-bg;
   }
 
@@ -79,6 +77,37 @@
 }
 
 
+// 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($list-group-border-radius);
+          @include border-bottom-left-radius(0);
+        }
+      }
+    }
+  }
+}
+
+
 // Flush list items
 //
 // Remove borders and border-radius to keep list group items edge-to-edge. Most
@@ -89,6 +118,10 @@
     border-right: 0;
     border-left: 0;
     @include border-radius(0);
+
+    &:last-child {
+      margin-bottom: -$list-group-border-width;
+    }
   }
 
   &:first-child {
@@ -99,6 +132,7 @@
 
   &:last-child {
     .list-group-item:last-child {
+      margin-bottom: 0;
       border-bottom: 0;
     }
   }

static/src/bootstrap/scss/_mixins.scss

@@ -2,6 +2,12 @@
 //
 // 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";

static/src/bootstrap/scss/_modal.scss

@@ -4,20 +4,25 @@
 // .modal-content   - actual modal w/ bg and corners and stuff
 
 
-// Kill the scroll on the body
 .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;
-  right: 0;
-  bottom: 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.
@@ -25,11 +30,6 @@
   // 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
-
-  .modal-open & {
-    overflow-x: hidden;
-    overflow-y: auto;
-  }
 }
 
 // Shell div to position the modal with bottom padding
@@ -43,17 +43,58 @@
   // When fading in the modal, animate it to slide down
   .modal.fade & {
     @include transition($modal-transition);
-    transform: translate(0, -25%);
+    transform: $modal-fade-transform;
   }
   .modal.show & {
-    transform: translate(0, 0);
+    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% - (#{$modal-dialog-margin} * 2));
+  min-height: calc(100% - #{$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
@@ -63,6 +104,7 @@
   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;
@@ -77,10 +119,10 @@
 .modal-backdrop {
   position: fixed;
   top: 0;
-  right: 0;
-  bottom: 0;
   left: 0;
   z-index: $zindex-modal-backdrop;
+  width: 100vw;
+  height: 100vh;
   background-color: $modal-backdrop-bg;
 
   // Fade for backdrop
@@ -101,7 +143,7 @@
   .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) (-$modal-header-padding) (-$modal-header-padding) auto;
+    margin: (-$modal-header-padding-y) (-$modal-header-padding-x) (-$modal-header-padding-y) auto;
   }
 }
 
@@ -128,6 +170,7 @@
   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; }
@@ -151,8 +194,20 @@
     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% - (#{$modal-dialog-margin-y-sm-up} * 2));
+    min-height: calc(100% - #{$modal-dialog-margin-y-sm-up * 2});
+
+    &::before {
+      height: calc(100vh - #{$modal-dialog-margin-y-sm-up * 2});
+    }
   }
 
   .modal-content {
@@ -160,9 +215,15 @@
   }
 
   .modal-sm { max-width: $modal-sm; }
-
 }
 
 @include media-breakpoint-up(lg) {
-  .modal-lg { max-width: $modal-lg; }
+  .modal-lg,
+  .modal-xl {
+    max-width: $modal-lg;
+  }
+}
+
+@include media-breakpoint-up(xl) {
+  .modal-xl { max-width: $modal-xl; }
 }

static/src/bootstrap/scss/_nav.scss

@@ -22,6 +22,8 @@
   // Disabled state lightens text
   &.disabled {
     color: $nav-link-disabled-color;
+    pointer-events: none;
+    cursor: default;
   }
 }
 

static/src/bootstrap/scss/_navbar.scss

@@ -24,7 +24,7 @@
   padding: $navbar-padding-y $navbar-padding-x;
 
   // Because flex properties aren't inherited, we need to redeclare these first
-  // few properities so that content nested within behave properly.
+  // few properties so that content nested within behave properly.
   > .container,
   > .container-fluid {
     display: flex;
@@ -44,7 +44,7 @@
   padding-top: $navbar-brand-padding-y;
   padding-bottom: $navbar-brand-padding-y;
   margin-right: $navbar-padding-x;
-  font-size: $navbar-brand-font-size;
+  @include font-size($navbar-brand-font-size);
   line-height: inherit;
   white-space: nowrap;
 
@@ -94,7 +94,7 @@
 // Powered by the collapse Bootstrap JavaScript plugin.
 
 // When collapsed, prevent the toggleable navbar contents from appearing in
-// the default flexbox row orienation. Requires the use of `flex-wrap: wrap`
+// the default flexbox row orientation. Requires the use of `flex-wrap: wrap`
 // on the `.navbar` parent.
 .navbar-collapse {
   flex-basis: 100%;
@@ -107,7 +107,7 @@
 // Button for toggling the navbar when in its collapsed state
 .navbar-toggler {
   padding: $navbar-toggler-padding-y $navbar-toggler-padding-x;
-  font-size: $navbar-toggler-font-size;
+  @include font-size($navbar-toggler-font-size);
   line-height: 1;
   background-color: transparent; // remove default button style
   border: $border-width solid transparent; // remove default button style
@@ -116,11 +116,6 @@
   @include hover-focus {
     text-decoration: none;
   }
-
-  // Opinionated: add "hand" cursor to non-disabled .navbar-toggler elements
-  &:not(:disabled):not(.disabled) {
-    cursor: pointer;
-  }
 }
 
 // Keep as a separate element so folks can easily override it with another icon
@@ -175,7 +170,7 @@
         }
 
         .navbar-collapse {
-          display: flex !important;  // stylelint-disable-line declaration-no-important
+          display: flex !important; // stylelint-disable-line declaration-no-important
 
           // Changes flex-bases to auto because of an IE10 bug
           flex-basis: auto;
@@ -197,10 +192,10 @@
 // Dark links against a light background
 .navbar-light {
   .navbar-brand {
-    color: $navbar-light-active-color;
+    color: $navbar-light-brand-color;
 
     @include hover-focus {
-      color: $navbar-light-active-color;
+      color: $navbar-light-brand-hover-color;
     }
   }
 
@@ -249,10 +244,10 @@
 // White links against a dark background
 .navbar-dark {
   .navbar-brand {
-    color: $navbar-dark-active-color;
+    color: $navbar-dark-brand-color;
 
     @include hover-focus {
-      color: $navbar-dark-active-color;
+      color: $navbar-dark-brand-hover-color;
     }
   }
 

static/src/bootstrap/scss/_pagination.scss

@@ -27,11 +27,6 @@
     outline: $pagination-focus-outline;
     box-shadow: $pagination-focus-box-shadow;
   }
-
-  // Opinionated: add "hand" cursor to non-disabled .page-link elements
-  &:not(:disabled):not(.disabled) {
-    cursor: pointer;
-  }
 }
 
 .page-item {

static/src/bootstrap/scss/_popover.scss

@@ -8,7 +8,7 @@
   // 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();
-  font-size: $popover-font-size;
+  @include font-size($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;
@@ -38,72 +38,63 @@
 .bs-popover-top {
   margin-bottom: $popover-arrow-height;
 
-  .arrow {
+  > .arrow {
     bottom: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
-  }
 
-  .arrow::before,
+    &::before {
-  .arrow::after {
+      bottom: 0;
-    border-width: $popover-arrow-height ($popover-arrow-width / 2) 0;
+      border-width: $popover-arrow-height ($popover-arrow-width / 2) 0;
-  }
+      border-top-color: $popover-arrow-outer-color;
+    }
 
-  .arrow::before {
+    &::after {
-    bottom: 0;
+      bottom: $popover-border-width;
-    border-top-color: $popover-arrow-outer-color;
+      border-width: $popover-arrow-height ($popover-arrow-width / 2) 0;
-  }
+      border-top-color: $popover-arrow-color;
-
+    }
-  .arrow::after {
-    bottom: $popover-border-width;
-    border-top-color: $popover-arrow-color;
   }
 }
 
 .bs-popover-right {
   margin-left: $popover-arrow-height;
 
-  .arrow {
+  > .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
-  }
 
-  .arrow::before,
+    &::before {
-  .arrow::after {
+      left: 0;
-    border-width: ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2) 0;
+      border-width: ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2) 0;
-  }
+      border-right-color: $popover-arrow-outer-color;
+    }
 
-  .arrow::before {
+    &::after {
-    left: 0;
+      left: $popover-border-width;
-    border-right-color: $popover-arrow-outer-color;
+      border-width: ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2) 0;
-  }
+      border-right-color: $popover-arrow-color;
-
+    }
-  .arrow::after {
-    left: $popover-border-width;
-    border-right-color: $popover-arrow-color;
   }
 }
 
 .bs-popover-bottom {
   margin-top: $popover-arrow-height;
 
-  .arrow {
+  > .arrow {
     top: calc((#{$popover-arrow-height} + #{$popover-border-width}) * -1);
-  }
 
-  .arrow::before,
+    &::before {
-  .arrow::after {
+      top: 0;
-    border-width: 0 ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2);
+      border-width: 0 ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2);
-  }
+      border-bottom-color: $popover-arrow-outer-color;
+    }
 
-  .arrow::before {
+    &::after {
-    top: 0;
+      top: $popover-border-width;
-    border-bottom-color: $popover-arrow-outer-color;
+      border-width: 0 ($popover-arrow-width / 2) $popover-arrow-height ($popover-arrow-width / 2);
-  }
+      border-bottom-color: $popover-arrow-color;
-
+    }
-  .arrow::after {
-    top: $popover-border-width;
-    border-bottom-color: $popover-arrow-color;
   }
 
   // This will remove the popover-header's border just below the arrow
@@ -113,7 +104,7 @@
     left: 50%;
     display: block;
     width: $popover-arrow-width;
-    margin-left: ($popover-arrow-width / -2);
+    margin-left: -$popover-arrow-width / 2;
     content: "";
     border-bottom: $popover-border-width solid $popover-header-bg;
   }
@@ -122,26 +113,23 @@
 .bs-popover-left {
   margin-right: $popover-arrow-height;
 
-  .arrow {
+  > .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
-  }
 
-  .arrow::before,
+    &::before {
-  .arrow::after {
+      right: 0;
-    border-width: ($popover-arrow-width / 2) 0 ($popover-arrow-width / 2) $popover-arrow-height;
+      border-width: ($popover-arrow-width / 2) 0 ($popover-arrow-width / 2) $popover-arrow-height;
-  }
+      border-left-color: $popover-arrow-outer-color;
+    }
 
-  .arrow::before {
+    &::after {
-    right: 0;
+      right: $popover-border-width;
-    border-left-color: $popover-arrow-outer-color;
+      border-width: ($popover-arrow-width / 2) 0 ($popover-arrow-width / 2) $popover-arrow-height;
-  }
+      border-left-color: $popover-arrow-color;
-
+    }
-  .arrow::after {
-    right: $popover-border-width;
-    border-left-color: $popover-arrow-color;
   }
 }
 
@@ -165,7 +153,7 @@
 .popover-header {
   padding: $popover-header-padding-y $popover-header-padding-x;
   margin-bottom: 0; // Reset the default from Reboot
-  font-size: $font-size-base;
+  @include font-size($font-size-base);
   color: $popover-header-color;
   background-color: $popover-header-bg;
   border-bottom: $popover-border-width solid darken($popover-header-bg, 5%);

static/src/bootstrap/scss/_print.scss

@@ -51,7 +51,7 @@
     }
     pre,
     blockquote {
-      border: $border-width solid $gray-500;   // Bootstrap custom code; using `$border-width` instead of 1px
+      border: $border-width solid $gray-500; // Bootstrap custom code; using `$border-width` instead of 1px
       page-break-inside: avoid;
     }
 

static/src/bootstrap/scss/_progress.scss

@@ -1,13 +1,16 @@
-@keyframes progress-bar-stripes {
+// Disable animation if transitions are disabled
-  from { background-position: $progress-height 0; }
+@if $enable-transitions {
-  to { background-position: 0 0; }
+  @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
-  font-size: $progress-font-size;
+  @include font-size($progress-font-size);
   background-color: $progress-bg;
   @include border-radius($progress-border-radius);
   @include box-shadow($progress-box-shadow);
@@ -29,6 +32,12 @@
   background-size: $progress-height $progress-height;
 }
 
-.progress-bar-animated {
+@if $enable-transitions {
-  animation: progress-bar-stripes $progress-bar-animation-timing;
+  .progress-bar-animated {
+    animation: progress-bar-stripes $progress-bar-animation-timing;
+
+    @media (prefers-reduced-motion: reduce) {
+      animation: none;
+    }
+  }
 }

static/src/bootstrap/scss/_reboot.scss

@@ -14,9 +14,7 @@
 // 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. Setting @viewport causes scrollbars to overlap content in IE11 and Edge, so
+// 5. Change the default tap highlight to be completely transparent in iOS.
-//    we force a non-overlapping, non-auto-hiding scrollbar to counteract.
-// 6. Change the default tap highlight to be completely transparent in iOS.
 
 *,
 *::before,
@@ -28,36 +26,27 @@ html {
   font-family: sans-serif; // 2
   line-height: 1.15; // 3
   -webkit-text-size-adjust: 100%; // 4
-  -ms-text-size-adjust: 100%; // 4
+  -webkit-tap-highlight-color: rgba($black, 0); // 5
-  -ms-overflow-style: scrollbar; // 5
-  -webkit-tap-highlight-color: rgba($black, 0); // 6
 }
 
-// IE10+ doesn't honor `<meta name="viewport">` in some cases.
-@at-root {
-  @-ms-viewport {
-    width: device-width;
-  }
-}
-
-// stylelint-disable selector-list-comma-newline-after
 // 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;
 }
-// stylelint-enable selector-list-comma-newline-after
 
 // 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
+// 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;
-  font-size: $font-size-base;
+  @include font-size($font-size-base);
   font-weight: $font-weight-base;
   line-height: $line-height-base;
   color: $body-color;
@@ -95,12 +84,11 @@ hr {
 //
 // 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 selector-list-comma-newline-after
+// stylelint-disable-next-line selector-list-comma-newline-after
 h1, h2, h3, h4, h5, h6 {
   margin-top: 0;
   margin-bottom: $headings-margin-bottom;
 }
-// stylelint-enable selector-list-comma-newline-after
 
 // Reset margins on paragraphs
 //
@@ -113,17 +101,19 @@ p {
 
 // Abbreviations
 //
-// 1. Remove the bottom border in Firefox 39-.
+// 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. Duplicate behavior to the data-* attribute for our tooltip plugin
+// 4. Remove the bottom border in Firefox 39-.
+// 5. Prevent the text-decoration to be skipped.
 
 abbr[title],
-abbr[data-original-title] { // 4
+abbr[data-original-title] { // 1
   text-decoration: underline; // 2
   text-decoration: underline dotted; // 2
   cursor: help; // 3
-  border-bottom: 0; // 1
+  border-bottom: 0; // 4
+  text-decoration-skip-ink: none; // 5
 }
 
 address {
@@ -159,19 +149,13 @@ blockquote {
   margin: 0 0 1rem;
 }
 
-dfn {
-  font-style: italic; // Add the correct font style in Android 4.3-
-}
-
-// stylelint-disable font-weight-notation
 b,
 strong {
-  font-weight: bolder; // Add the correct font weight in Chrome, Edge, and Safari
+  font-weight: $font-weight-bolder; // Add the correct font weight in Chrome, Edge, and Safari
 }
-// stylelint-enable font-weight-notation
 
 small {
-  font-size: 80%; // Add the correct font size in all browsers
+  @include font-size(80%); // Add the correct font size in all browsers
 }
 
 //
@@ -182,7 +166,7 @@ small {
 sub,
 sup {
   position: relative;
-  font-size: 75%;
+  @include font-size(75%);
   line-height: 0;
   vertical-align: baseline;
 }
@@ -199,7 +183,6 @@ a {
   color: $link-color;
   text-decoration: $link-decoration;
   background-color: transparent; // Remove the gray background on active links in IE 10.
-  -webkit-text-decoration-skip: objects; // Remove gaps in links underline in iOS 8+ and Safari 8+.
 
   @include hover {
     color: $link-hover-color;
@@ -237,7 +220,7 @@ code,
 kbd,
 samp {
   font-family: $font-family-monospace;
-  font-size: 1em; // Correct the odd `em` font sizing in all browsers.
+  @include font-size(1em); // Correct the odd `em` font sizing in all browsers.
 }
 
 pre {
@@ -247,9 +230,6 @@ pre {
   margin-bottom: 1rem;
   // Don't allow content to break outside
   overflow: auto;
-  // We have @viewport set which causes scrollbars to overlap content in IE11 and Edge, so
-  // we force a non-overlapping, non-auto-hiding scrollbar to counteract.
-  -ms-overflow-style: scrollbar;
 }
 
 
@@ -272,8 +252,11 @@ img {
   border-style: none; // Remove the border on images inside links in IE 10-.
 }
 
-svg:not(:root) {
+svg {
-  overflow: hidden; // Hide the overflow in IE
+  // 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;
 }
 
 
@@ -314,6 +297,7 @@ label {
 //
 // Details at https://github.com/twbs/bootstrap/issues/24093
 button {
+  // stylelint-disable-next-line property-blacklist
   border-radius: 0;
 }
 
@@ -333,7 +317,7 @@ optgroup,
 textarea {
   margin: 0; // Remove the margin in Firefox and Safari
   font-family: inherit;
-  font-size: inherit;
+  @include font-size(inherit);
   line-height: inherit;
 }
 
@@ -347,16 +331,36 @@ 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,
-html [type="button"], // 1
+[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,
@@ -412,7 +416,7 @@ legend {
   max-width: 100%; // 1
   padding: 0;
   margin-bottom: .5rem;
-  font-size: 1.5rem;
+  @include font-size(1.5rem);
   line-height: inherit;
   color: inherit; // 2
   white-space: normal; // 1
@@ -438,10 +442,9 @@ progress {
 }
 
 //
-// Remove the inner padding and cancel buttons in Chrome and Safari on macOS.
+// Remove the inner padding in Chrome and Safari on macOS.
 //
 
-[type="search"]::-webkit-search-cancel-button,
 [type="search"]::-webkit-search-decoration {
   -webkit-appearance: none;
 }

static/src/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;
+}

static/src/bootstrap/scss/_tables.scss

@@ -4,8 +4,8 @@
 
 .table {
   width: 100%;
-  max-width: 100%;
   margin-bottom: $spacer;
+  color: $table-color;
   background-color: $table-bg; // Reset for nesting within parents with `background-color`.
 
   th,
@@ -23,10 +23,6 @@
   tbody + tbody {
     border-top: (2 * $table-border-width) solid $table-border-color;
   }
-
-  .table {
-    background-color: $body-bg;
-  }
 }
 
 
@@ -57,7 +53,7 @@
   thead {
     th,
     td {
-      border-bottom-width: (2 * $table-border-width);
+      border-bottom-width: 2 * $table-border-width;
     }
   }
 }
@@ -89,6 +85,7 @@
 .table-hover {
   tbody tr {
     @include hover {
+      color: $table-hover-color;
       background-color: $table-hover-bg;
     }
   }
@@ -101,7 +98,7 @@
 // inheritance to nested tables.
 
 @each $color, $value in $theme-colors {
-  @include table-row-variant($color, theme-color-level($color, -9));
+  @include table-row-variant($color, theme-color-level($color, $table-bg-level), theme-color-level($color, $table-border-level));
 }
 
 @include table-row-variant(active, $table-active-bg);
@@ -153,6 +150,7 @@
   &.table-hover {
     tbody tr {
       @include hover {
+        color: $table-dark-hover-color;
         background-color: $table-dark-hover-bg;
       }
     }
@@ -176,7 +174,6 @@
         width: 100%;
         overflow-x: auto;
         -webkit-overflow-scrolling: touch;
-        -ms-overflow-style: -ms-autohiding-scrollbar; // See https://github.com/twbs/bootstrap/pull/10057
 
         // Prevent double border on horizontal scroll due to use of `display: block;`
         > .table-bordered {

static/src/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
+}

static/src/bootstrap/scss/_tooltip.scss

@@ -7,7 +7,7 @@
   // 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();
-  font-size: $tooltip-font-size;
+  @include font-size($tooltip-font-size);
   // Allow breaking very long words so they don't overflow the tooltip's bounds
   word-wrap: break-word;
   opacity: 0;

static/src/bootstrap/scss/_transitions.scss

@@ -1,5 +1,3 @@
-// stylelint-disable selector-no-qualifying-type
-
 .fade {
   @include transition($transition-fade);
 

static/src/bootstrap/scss/_type.scss

@@ -13,36 +13,36 @@ h1, h2, h3, h4, h5, h6,
   color: $headings-color;
 }
 
-h1, .h1 { font-size: $h1-font-size; }
+h1, .h1 { @include font-size($h1-font-size); }
-h2, .h2 { font-size: $h2-font-size; }
+h2, .h2 { @include font-size($h2-font-size); }
-h3, .h3 { font-size: $h3-font-size; }
+h3, .h3 { @include font-size($h3-font-size); }
-h4, .h4 { font-size: $h4-font-size; }
+h4, .h4 { @include font-size($h4-font-size); }
-h5, .h5 { font-size: $h5-font-size; }
+h5, .h5 { @include font-size($h5-font-size); }
-h6, .h6 { font-size: $h6-font-size; }
+h6, .h6 { @include font-size($h6-font-size); }
 
 .lead {
-  font-size: $lead-font-size;
+  @include font-size($lead-font-size);
   font-weight: $lead-font-weight;
 }
 
 // Type display classes
 .display-1 {
-  font-size: $display1-size;
+  @include font-size($display1-size);
   font-weight: $display1-weight;
   line-height: $display-line-height;
 }
 .display-2 {
-  font-size: $display2-size;
+  @include font-size($display2-size);
   font-weight: $display2-weight;
   line-height: $display-line-height;
 }
 .display-3 {
-  font-size: $display3-size;
+  @include font-size($display3-size);
   font-weight: $display3-weight;
   line-height: $display-line-height;
 }
 .display-4 {
-  font-size: $display4-size;
+  @include font-size($display4-size);
   font-weight: $display4-weight;
   line-height: $display-line-height;
 }
@@ -66,7 +66,7 @@ hr {
 
 small,
 .small {
-  font-size: $small-font-size;
+  @include font-size($small-font-size);
   font-weight: $font-weight-normal;
 }
 
@@ -104,22 +104,22 @@ mark,
 
 // Builds on `abbr`
 .initialism {
-  font-size: 90%;
+  @include font-size(90%);
   text-transform: uppercase;
 }
 
 // Blockquotes
 .blockquote {
   margin-bottom: $spacer;
-  font-size: $blockquote-font-size;
+  @include font-size($blockquote-font-size);
 }
 
 .blockquote-footer {
   display: block;
-  font-size: 80%; // back to default font-size
+  @include font-size($blockquote-small-font-size);
   color: $blockquote-small-color;
 
   &::before {
-    content: "\2014 \00A0"; // em dash, nbsp
+    content: "\2014\00A0"; // em dash, nbsp
   }
 }

static/src/bootstrap/scss/_utilities.scss

@@ -6,10 +6,12 @@
 @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";

static/src/bootstrap/scss/_variables.scss

@@ -3,12 +3,8 @@
 // Variables should follow the `$component-state-property-size` formula for
 // consistent naming. Ex: $nav-link-disabled-color and $modal-content-box-shadow-xs.
 
-
-//
 // Color system
-//
 
-// stylelint-disable
 $white:    #fff !default;
 $gray-100: #f8f9fa !default;
 $gray-200: #e9ecef !default;
@@ -22,17 +18,21 @@ $gray-900: #212529 !default;
 $black:    #000 !default;
 
 $grays: () !default;
-$grays: map-merge((
+// stylelint-disable-next-line scss/dollar-variable-default
-  "100": $gray-100,
+$grays: map-merge(
-  "200": $gray-200,
+  (
-  "300": $gray-300,
+    "100": $gray-100,
-  "400": $gray-400,
+    "200": $gray-200,
-  "500": $gray-500,
+    "300": $gray-300,
-  "600": $gray-600,
+    "400": $gray-400,
-  "700": $gray-700,
+    "500": $gray-500,
-  "800": $gray-800,
+    "600": $gray-600,
-  "900": $gray-900
+    "700": $gray-700,
-), $grays);
+    "800": $gray-800,
+    "900": $gray-900
+  ),
+  $grays
+);
 
 $blue:    #007bff !default;
 $indigo:  #6610f2 !default;
@@ -46,21 +46,25 @@ $teal:    #20c997 !default;
 $cyan:    #17a2b8 !default;
 
 $colors: () !default;
-$colors: map-merge((
+// stylelint-disable-next-line scss/dollar-variable-default
-  "blue":       $blue,
+$colors: map-merge(
-  "indigo":     $indigo,
+  (
-  "purple":     $purple,
+    "blue":       $blue,
-  "pink":       $pink,
+    "indigo":     $indigo,
-  "red":        $red,
+    "purple":     $purple,
-  "orange":     $orange,
+    "pink":       $pink,
-  "yellow":     $yellow,
+    "red":        $red,
-  "green":      $green,
+    "orange":     $orange,
-  "teal":       $teal,
+    "yellow":     $yellow,
-  "cyan":       $cyan,
+    "green":      $green,
-  "white":      $white,
+    "teal":       $teal,
-  "gray":       $gray-600,
+    "cyan":       $cyan,
-  "gray-dark":  $gray-800
+    "white":      $white,
-), $colors);
+    "gray":       $gray-600,
+    "gray-dark":  $gray-800
+  ),
+  $colors
+);
 
 $primary:       $blue !default;
 $secondary:     $gray-600 !default;
@@ -72,17 +76,20 @@ $light:         $gray-100 !default;
 $dark:          $gray-800 !default;
 
 $theme-colors: () !default;
-$theme-colors: map-merge((
+// stylelint-disable-next-line scss/dollar-variable-default
-  "primary":    $primary,
+$theme-colors: map-merge(
-  "secondary":  $secondary,
+  (
-  "success":    $success,
+    "primary":    $primary,
-  "info":       $info,
+    "secondary":  $secondary,
-  "warning":    $warning,
+    "success":    $success,
-  "danger":     $danger,
+    "info":       $info,
-  "light":      $light,
+    "warning":    $warning,
-  "dark":       $dark
+    "danger":     $danger,
-), $theme-colors);
+    "light":      $light,
-// stylelint-enable
+    "dark":       $dark
+  ),
+  $theme-colors
+);
 
 // Set a specific jump point for requesting color jumps
 $theme-color-interval:      8% !default;
@@ -94,18 +101,24 @@ $yiq-contrasted-threshold:  150 !default;
 $yiq-text-dark:             $gray-900 !default;
 $yiq-text-light:            $white !default;
 
+
 // Options
 //
 // Quickly modify global styling by enabling or disabling optional features.
 
-$enable-caret:              true !default;
+$enable-caret:                                true !default;
-$enable-rounded:            true !default;
+$enable-rounded:                              true !default;
-$enable-shadows:            false !default;
+$enable-shadows:                              false !default;
-$enable-gradients:          false !default;
+$enable-gradients:                            false !default;
-$enable-transitions:        true !default;
+$enable-transitions:                          true !default;
-$enable-hover-media-query:  false !default; // Deprecated, no longer affects any compiled CSS
+$enable-prefers-reduced-motion-media-query:   true !default;
-$enable-grid-classes:       true !default;
+$enable-hover-media-query:                    false !default; // Deprecated, no longer affects any compiled CSS
-$enable-print-styles:       true !default;
+$enable-grid-classes:                         true !default;
+$enable-pointer-cursor-for-buttons:           true !default;
+$enable-print-styles:                         true !default;
+$enable-responsive-font-sizes:                false !default;
+$enable-validation-icons:                     true !default;
+$enable-deprecation-messages:                 true !default;
 
 
 // Spacing
@@ -114,28 +127,35 @@ $enable-print-styles:       true !default;
 // variables. Mostly focused on spacing.
 // You can add more entries to the $spacers map, should you need more variation.
 
-// stylelint-disable
 $spacer: 1rem !default;
 $spacers: () !default;
-$spacers: map-merge((
+// stylelint-disable-next-line scss/dollar-variable-default
-  0: 0,
+$spacers: map-merge(
-  1: ($spacer * .25),
+  (
-  2: ($spacer * .5),
+    0: 0,
-  3: $spacer,
+    1: ($spacer * .25),
-  4: ($spacer * 1.5),
+    2: ($spacer * .5),
-  5: ($spacer * 3)
+    3: $spacer,
-), $spacers);
+    4: ($spacer * 1.5),
+    5: ($spacer * 3)
+  ),
+  $spacers
+);
 
 // This variable affects the `.h-*` and `.w-*` classes.
 $sizes: () !default;
-$sizes: map-merge((
+// stylelint-disable-next-line scss/dollar-variable-default
-  25: 25%,
+$sizes: map-merge(
-  50: 50%,
+  (
-  75: 75%,
+    25: 25%,
-  100: 100%,
+    50: 50%,
-  auto: auto
+    75: 75%,
-), $sizes);
+    100: 100%,
-// stylelint-enable
+    auto: auto
+  ),
+  $sizes
+);
+
 
 // Body
 //
@@ -144,14 +164,17 @@ $sizes: map-merge((
 $body-bg:                   $white !default;
 $body-color:                $gray-900 !default;
 
+
 // Links
 //
 // Style anchor elements.
 
-$link-color:                theme-color("primary") !default;
+$link-color:                              theme-color("primary") !default;
-$link-decoration:           none !default;
+$link-decoration:                         none !default;
-$link-hover-color:          darken($link-color, 15%) !default;
+$link-hover-color:                        darken($link-color, 15%) !default;
-$link-hover-decoration:     underline !default;
+$link-hover-decoration:                   underline !default;
+// Darken percentage for links with `.text-*` class (e.g. `.text-success`)
+$emphasized-link-hover-darken-percentage: 15% !default;
 
 // Paragraphs
 //
@@ -174,7 +197,7 @@ $grid-breakpoints: (
 ) !default;
 
 @include _assert-ascending($grid-breakpoints, "$grid-breakpoints");
-@include _assert-starts-at-zero($grid-breakpoints);
+@include _assert-starts-at-zero($grid-breakpoints, "$grid-breakpoints");
 
 
 // Grid containers
@@ -198,6 +221,7 @@ $container-max-widths: (
 $grid-columns:                12 !default;
 $grid-gutter-width:           30px !default;
 
+
 // Components
 //
 // Define common padding and border radius sizes and more.
@@ -212,6 +236,8 @@ $border-radius:               .25rem !default;
 $border-radius-lg:            .3rem !default;
 $border-radius-sm:            .2rem !default;
 
+$rounded-pill:                50rem !default;
+
 $box-shadow-sm:               0 .125rem .25rem rgba($black, .075) !default;
 $box-shadow:                  0 .5rem 1rem rgba($black, .15) !default;
 $box-shadow-lg:               0 1rem 3rem rgba($black, .175) !default;
@@ -220,29 +246,44 @@ $component-active-color:      $white !default;
 $component-active-bg:         theme-color("primary") !default;
 
 $caret-width:                 .3em !default;
+$caret-vertical-align:        $caret-width * .85 !default;
+$caret-spacing:               $caret-width * .85 !default;
 
 $transition-base:             all .2s ease-in-out !default;
 $transition-fade:             opacity .15s linear !default;
 $transition-collapse:         height .35s ease !default;
 
+$embed-responsive-aspect-ratios: () !default;
+// stylelint-disable-next-line scss/dollar-variable-default
+$embed-responsive-aspect-ratios: join(
+  (
+    (21 9),
+    (16 9),
+    (4 3),
+    (1 1),
+  ),
+  $embed-responsive-aspect-ratios
+);
 
-// Fonts
+// Typography
 //
 // Font, line-height, and color for body text, headings, and more.
 
 // stylelint-disable value-keyword-case
-$font-family-sans-serif:      -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol" !default;
+$font-family-sans-serif:      -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji" !default;
 $font-family-monospace:       SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace !default;
 $font-family-base:            $font-family-sans-serif !default;
 // stylelint-enable value-keyword-case
 
 $font-size-base:              1rem !default; // Assumes the browser default, typically `16px`
-$font-size-lg:                ($font-size-base * 1.25) !default;
+$font-size-lg:                $font-size-base * 1.25 !default;
-$font-size-sm:                ($font-size-base * .875) !default;
+$font-size-sm:                $font-size-base * .875 !default;
 
+$font-weight-lighter:         lighter !default;
 $font-weight-light:           300 !default;
 $font-weight-normal:          400 !default;
 $font-weight-bold:            700 !default;
+$font-weight-bolder:          bolder !default;
 
 $font-weight-base:            $font-weight-normal !default;
 $line-height-base:            1.5 !default;
@@ -254,11 +295,11 @@ $h4-font-size:                $font-size-base * 1.5 !default;
 $h5-font-size:                $font-size-base * 1.25 !default;
 $h6-font-size:                $font-size-base !default;
 
-$headings-margin-bottom:      ($spacer / 2) !default;
+$headings-margin-bottom:      $spacer / 2 !default;
-$headings-font-family:        inherit !default;
+$headings-font-family:        null !default;
 $headings-font-weight:        500 !default;
 $headings-line-height:        1.2 !default;
-$headings-color:              inherit !default;
+$headings-color:              null !default;
 
 $display1-size:               6rem !default;
 $display2-size:               5.5rem !default;
@@ -271,7 +312,7 @@ $display3-weight:             300 !default;
 $display4-weight:             300 !default;
 $display-line-height:         $headings-line-height !default;
 
-$lead-font-size:              ($font-size-base * 1.25) !default;
+$lead-font-size:              $font-size-base * 1.25 !default;
 $lead-font-weight:            300 !default;
 
 $small-font-size:             80% !default;
@@ -279,7 +320,8 @@ $small-font-size:             80% !default;
 $text-muted:                  $gray-600 !default;
 
 $blockquote-small-color:      $gray-600 !default;
-$blockquote-font-size:        ($font-size-base * 1.25) !default;
+$blockquote-small-font-size:  $small-font-size !default;
+$blockquote-font-size:        $font-size-base * 1.25 !default;
 
 $hr-border-color:             rgba($black, .1) !default;
 $hr-border-width:             $border-width !default;
@@ -305,33 +347,43 @@ $hr-margin-y:                 $spacer !default;
 $table-cell-padding:          .75rem !default;
 $table-cell-padding-sm:       .3rem !default;
 
-$table-bg:                    transparent !default;
+$table-color:                 $body-color !default;
+$table-bg:                    null !default;
 $table-accent-bg:             rgba($black, .05) !default;
+$table-hover-color:           $table-color !default;
 $table-hover-bg:              rgba($black, .075) !default;
 $table-active-bg:             $table-hover-bg !default;
 
 $table-border-width:          $border-width !default;
-$table-border-color:          $gray-300 !default;
+$table-border-color:          $border-color !default;
 
 $table-head-bg:               $gray-200 !default;
 $table-head-color:            $gray-700 !default;
 
-$table-dark-bg:               $gray-900 !default;
+$table-dark-color:            $white !default;
+$table-dark-bg:               $gray-800 !default;
 $table-dark-accent-bg:        rgba($white, .05) !default;
+$table-dark-hover-color:      $table-dark-color !default;
 $table-dark-hover-bg:         rgba($white, .075) !default;
-$table-dark-border-color:     lighten($gray-900, 7.5%) !default;
+$table-dark-border-color:     lighten($table-dark-bg, 7.5%) !default;
-$table-dark-color:            $body-bg !default;
+$table-dark-color:            $white !default;
 
 $table-striped-order:         odd !default;
 
 $table-caption-color:         $text-muted !default;
 
+$table-bg-level:              -9 !default;
+$table-border-level:          -6 !default;
+
+
 // Buttons + Forms
 //
 // Shared variables that are reassigned to `$input-` and `$btn-` specific variables.
 
 $input-btn-padding-y:         .375rem !default;
 $input-btn-padding-x:         .75rem !default;
+$input-btn-font-family:       null !default;
+$input-btn-font-size:         $font-size-base !default;
 $input-btn-line-height:       $line-height-base !default;
 
 $input-btn-focus-width:       .2rem !default;
@@ -340,10 +392,12 @@ $input-btn-focus-box-shadow:  0 0 0 $input-btn-focus-width $input-btn-focus-colo
 
 $input-btn-padding-y-sm:      .25rem !default;
 $input-btn-padding-x-sm:      .5rem !default;
+$input-btn-font-size-sm:      $font-size-sm !default;
 $input-btn-line-height-sm:    $line-height-sm !default;
 
 $input-btn-padding-y-lg:      .5rem !default;
 $input-btn-padding-x-lg:      1rem !default;
+$input-btn-font-size-lg:      $font-size-lg !default;
 $input-btn-line-height-lg:    $line-height-lg !default;
 
 $input-btn-border-width:      $border-width !default;
@@ -355,14 +409,18 @@ $input-btn-border-width:      $border-width !default;
 
 $btn-padding-y:               $input-btn-padding-y !default;
 $btn-padding-x:               $input-btn-padding-x !default;
+$btn-font-family:             $input-btn-font-family !default;
+$btn-font-size:               $input-btn-font-size !default;
 $btn-line-height:             $input-btn-line-height !default;
 
 $btn-padding-y-sm:            $input-btn-padding-y-sm !default;
 $btn-padding-x-sm:            $input-btn-padding-x-sm !default;
+$btn-font-size-sm:            $input-btn-font-size-sm !default;
 $btn-line-height-sm:          $input-btn-line-height-sm !default;
 
 $btn-padding-y-lg:            $input-btn-padding-y-lg !default;
 $btn-padding-x-lg:            $input-btn-padding-x-lg !default;
+$btn-font-size-lg:            $input-btn-font-size-lg !default;
 $btn-line-height-lg:          $input-btn-line-height-lg !default;
 
 $btn-border-width:            $input-btn-border-width !default;
@@ -392,14 +450,19 @@ $label-margin-bottom:                   .5rem !default;
 
 $input-padding-y:                       $input-btn-padding-y !default;
 $input-padding-x:                       $input-btn-padding-x !default;
+$input-font-family:                     $input-btn-font-family !default;
+$input-font-size:                       $input-btn-font-size !default;
+$input-font-weight:                     $font-weight-base !default;
 $input-line-height:                     $input-btn-line-height !default;
 
 $input-padding-y-sm:                    $input-btn-padding-y-sm !default;
 $input-padding-x-sm:                    $input-btn-padding-x-sm !default;
+$input-font-size-sm:                    $input-btn-font-size-sm !default;
 $input-line-height-sm:                  $input-btn-line-height-sm !default;
 
 $input-padding-y-lg:                    $input-btn-padding-y-lg !default;
 $input-padding-x-lg:                    $input-btn-padding-x-lg !default;
+$input-font-size-lg:                    $input-btn-font-size-lg !default;
 $input-line-height-lg:                  $input-btn-line-height-lg !default;
 
 $input-bg:                              $white !default;
@@ -425,14 +488,13 @@ $input-plaintext-color:                 $body-color !default;
 
 $input-height-border:                   $input-border-width * 2 !default;
 
-$input-height-inner:                    ($font-size-base * $input-btn-line-height) + ($input-btn-padding-y * 2) !default;
+$input-height-inner:                    calc(#{$input-line-height * 1em} + #{$input-padding-y * 2}) !default;
-$input-height:                          calc(#{$input-height-inner} + #{$input-height-border}) !default;
+$input-height-inner-half:               calc(#{$input-line-height * .5em} + #{$input-padding-y}) !default;
+$input-height-inner-quarter:            calc(#{$input-line-height * .25em} + #{$input-padding-y / 2}) !default;
 
-$input-height-inner-sm:                 ($font-size-sm * $input-btn-line-height-sm) + ($input-btn-padding-y-sm * 2) !default;
+$input-height:                          calc(#{$input-line-height * 1em} + #{$input-padding-y * 2} + #{$input-height-border}) !default;
-$input-height-sm:                       calc(#{$input-height-inner-sm} + #{$input-height-border}) !default;
+$input-height-sm:                       calc(#{$input-line-height-sm * 1em} + #{$input-btn-padding-y-sm * 2} + #{$input-height-border}) !default;
-
+$input-height-lg:                       calc(#{$input-line-height-lg * 1em} + #{$input-btn-padding-y-lg * 2} + #{$input-height-border}) !default;
-$input-height-inner-lg:                 ($font-size-lg * $input-btn-line-height-lg) + ($input-btn-padding-y-lg * 2) !default;
-$input-height-lg:                       calc(#{$input-height-inner-lg} + #{$input-height-border}) !default;
 
 $input-transition:                      border-color .15s ease-in-out, box-shadow .15s ease-in-out !default;
 
@@ -445,68 +507,97 @@ $form-check-input-margin-x:             .25rem !default;
 $form-check-inline-margin-x:            .75rem !default;
 $form-check-inline-input-margin-x:      .3125rem !default;
 
+$form-grid-gutter-width:                10px !default;
 $form-group-margin-bottom:              1rem !default;
 
 $input-group-addon-color:               $input-color !default;
 $input-group-addon-bg:                  $gray-200 !default;
 $input-group-addon-border-color:        $input-border-color !default;
 
-$custom-control-gutter:                 1.5rem !default;
+$custom-forms-transition:               background-color .15s ease-in-out, border-color .15s ease-in-out, box-shadow .15s ease-in-out !default;
+
+$custom-control-gutter:                 .5rem !default;
 $custom-control-spacer-x:               1rem !default;
 
 $custom-control-indicator-size:         1rem !default;
-$custom-control-indicator-bg:           $gray-300 !default;
+$custom-control-indicator-bg:           $input-bg !default;
-$custom-control-indicator-bg-size:      50% 50% !default;
-$custom-control-indicator-box-shadow:   inset 0 .25rem .25rem rgba($black, .1) !default;
 
-$custom-control-indicator-disabled-bg:          $gray-200 !default;
+$custom-control-indicator-bg-size:      50% 50% !default;
+$custom-control-indicator-box-shadow:   $input-box-shadow !default;
+$custom-control-indicator-border-color: $gray-500 !default;
+$custom-control-indicator-border-width: $input-border-width !default;
+
+$custom-control-indicator-disabled-bg:          $input-disabled-bg !default;
 $custom-control-label-disabled-color:           $gray-600 !default;
 
 $custom-control-indicator-checked-color:        $component-active-color !default;
 $custom-control-indicator-checked-bg:           $component-active-bg !default;
 $custom-control-indicator-checked-disabled-bg:  rgba(theme-color("primary"), .5) !default;
 $custom-control-indicator-checked-box-shadow:   none !default;
+$custom-control-indicator-checked-border-color: $custom-control-indicator-checked-bg !default;
 
-$custom-control-indicator-focus-box-shadow:     0 0 0 1px $body-bg, $input-btn-focus-box-shadow !default;
+$custom-control-indicator-focus-box-shadow:     $input-focus-box-shadow !default;
+$custom-control-indicator-focus-border-color:   $input-focus-border-color !default;
 
 $custom-control-indicator-active-color:         $component-active-color !default;
 $custom-control-indicator-active-bg:            lighten($component-active-bg, 35%) !default;
 $custom-control-indicator-active-box-shadow:    none !default;
+$custom-control-indicator-active-border-color:  $custom-control-indicator-active-bg !default;
 
 $custom-checkbox-indicator-border-radius:       $border-radius !default;
-$custom-checkbox-indicator-icon-checked:        str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3E%3Cpath fill='#{$custom-control-indicator-checked-color}' d='M6.564.75l-3.59 3.612-1.538-1.55L0 4.26 2.974 7.25 8 2.193z'/%3E%3C/svg%3E"), "#", "%23") !default;
+$custom-checkbox-indicator-icon-checked:        str-replace(url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='#{$custom-control-indicator-checked-color}' d='M6.564.75l-3.59 3.612-1.538-1.55L0 4.26 2.974 7.25 8 2.193z'/%3e%3c/svg%3e"), "#", "%23") !default;
 
-$custom-checkbox-indicator-indeterminate-bg:          $component-active-bg !default;
+$custom-checkbox-indicator-indeterminate-bg:           $component-active-bg !default;
-$custom-checkbox-indicator-indeterminate-color:       $custom-control-indicator-checked-color !default;
+$custom-checkbox-indicator-indeterminate-color:        $custom-control-indicator-checked-color !default;
-$custom-checkbox-indicator-icon-indeterminate:        str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 4 4'%3E%3Cpath stroke='#{$custom-checkbox-indicator-indeterminate-color}' d='M0 2h4'/%3E%3C/svg%3E"), "#", "%23") !default;
+$custom-checkbox-indicator-icon-indeterminate:         str-replace(url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 4 4'%3e%3cpath stroke='#{$custom-checkbox-indicator-indeterminate-color}' d='M0 2h4'/%3e%3c/svg%3e"), "#", "%23") !default;
-$custom-checkbox-indicator-indeterminate-box-shadow:  none !default;
+$custom-checkbox-indicator-indeterminate-box-shadow:   none !default;
+$custom-checkbox-indicator-indeterminate-border-color: $custom-checkbox-indicator-indeterminate-bg !default;
 
 $custom-radio-indicator-border-radius:          50% !default;
-$custom-radio-indicator-icon-checked:           str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3E%3Ccircle r='3' fill='#{$custom-control-indicator-checked-color}'/%3E%3C/svg%3E"), "#", "%23") !default;
+$custom-radio-indicator-icon-checked:           str-replace(url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'%3e%3ccircle r='3' fill='#{$custom-control-indicator-checked-color}'/%3e%3c/svg%3e"), "#", "%23") !default;
 
-$custom-select-padding-y:           .375rem !default;
+$custom-switch-width:                           $custom-control-indicator-size * 1.75 !default;
-$custom-select-padding-x:           .75rem !default;
+$custom-switch-indicator-border-radius:         $custom-control-indicator-size / 2 !default;
+$custom-switch-indicator-size:                  calc(#{$custom-control-indicator-size} - #{$custom-control-indicator-border-width * 4}) !default;
+
+$custom-select-padding-y:           $input-padding-y !default;
+$custom-select-padding-x:           $input-padding-x !default;
+$custom-select-font-family:         $input-font-family !default;
+$custom-select-font-size:           $input-font-size !default;
 $custom-select-height:              $input-height !default;
 $custom-select-indicator-padding:   1rem !default; // Extra padding to account for the presence of the background-image based indicator
-$custom-select-line-height:         $input-btn-line-height !default;
+$custom-select-font-weight:         $input-font-weight !default;
+$custom-select-line-height:         $input-line-height !default;
 $custom-select-color:               $input-color !default;
 $custom-select-disabled-color:      $gray-600 !default;
 $custom-select-bg:                  $input-bg !default;
 $custom-select-disabled-bg:         $gray-200 !default;
 $custom-select-bg-size:             8px 10px !default; // In pixels because image dimensions
 $custom-select-indicator-color:     $gray-800 !default;
-$custom-select-indicator:           str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 4 5'%3E%3Cpath fill='#{$custom-select-indicator-color}' d='M2 0L0 2h4zm0 5L0 3h4z'/%3E%3C/svg%3E"), "#", "%23") !default;
+$custom-select-indicator:           str-replace(url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 4 5'%3e%3cpath fill='#{$custom-select-indicator-color}' d='M2 0L0 2h4zm0 5L0 3h4z'/%3e%3c/svg%3e"), "#", "%23") !default;
-$custom-select-border-width:        $input-btn-border-width !default;
+$custom-select-background:          $custom-select-indicator no-repeat right $custom-select-padding-x center / $custom-select-bg-size !default; // Used so we can have multiple background elements (e.g., arrow and feedback icon)
+
+$custom-select-feedback-icon-padding-right: calc((1em + #{2 * $custom-select-padding-y}) * 3 / 4 + #{$custom-select-padding-x + $custom-select-indicator-padding}) !default;
+$custom-select-feedback-icon-position:      center right ($custom-select-padding-x + $custom-select-indicator-padding) !default;
+$custom-select-feedback-icon-size:          $input-height-inner-half $input-height-inner-half !default;
+
+$custom-select-border-width:        $input-border-width !default;
 $custom-select-border-color:        $input-border-color !default;
 $custom-select-border-radius:       $border-radius !default;
+$custom-select-box-shadow:          inset 0 1px 2px rgba($black, .075) !default;
 
 $custom-select-focus-border-color:  $input-focus-border-color !default;
-$custom-select-focus-box-shadow:    inset 0 1px 2px rgba($black, .075), 0 0 5px rgba($custom-select-focus-border-color, .5) !default;
+$custom-select-focus-width:         $input-focus-width !default;
+$custom-select-focus-box-shadow:    0 0 0 $custom-select-focus-width $input-btn-focus-color !default;
 
-$custom-select-font-size-sm:        75% !default;
+$custom-select-padding-y-sm:        $input-padding-y-sm !default;
+$custom-select-padding-x-sm:        $input-padding-x-sm !default;
+$custom-select-font-size-sm:        $input-font-size-sm !default;
 $custom-select-height-sm:           $input-height-sm !default;
 
-$custom-select-font-size-lg:        125% !default;
+$custom-select-padding-y-lg:        $input-padding-y-lg !default;
+$custom-select-padding-x-lg:        $input-padding-x-lg !default;
+$custom-select-font-size-lg:        $input-font-size-lg !default;
 $custom-select-height-lg:           $input-height-lg !default;
 
 $custom-range-track-width:          100% !default;
@@ -516,26 +607,31 @@ $custom-range-track-bg:             $gray-300 !default;
 $custom-range-track-border-radius:  1rem !default;
 $custom-range-track-box-shadow:     inset 0 .25rem .25rem rgba($black, .1) !default;
 
-$custom-range-thumb-width:            1rem !default;
+$custom-range-thumb-width:                   1rem !default;
-$custom-range-thumb-height:           $custom-range-thumb-width !default;
+$custom-range-thumb-height:                  $custom-range-thumb-width !default;
-$custom-range-thumb-bg:               $component-active-bg !default;
+$custom-range-thumb-bg:                      $component-active-bg !default;
-$custom-range-thumb-border:           0 !default;
+$custom-range-thumb-border:                  0 !default;
-$custom-range-thumb-border-radius:    1rem !default;
+$custom-range-thumb-border-radius:           1rem !default;
-$custom-range-thumb-box-shadow:       0 .1rem .25rem rgba($black, .1) !default;
+$custom-range-thumb-box-shadow:              0 .1rem .25rem rgba($black, .1) !default;
-$custom-range-thumb-focus-box-shadow: 0 0 0 1px $body-bg, $input-btn-focus-box-shadow !default;
+$custom-range-thumb-focus-box-shadow:        0 0 0 1px $body-bg, $input-focus-box-shadow !default;
-$custom-range-thumb-active-bg:        lighten($component-active-bg, 35%) !default;
+$custom-range-thumb-focus-box-shadow-width:  $input-focus-width !default; // For focus box shadow issue in IE/Edge
+$custom-range-thumb-active-bg:               lighten($component-active-bg, 35%) !default;
+$custom-range-thumb-disabled-bg:             $gray-500 !default;
 
 $custom-file-height:                $input-height !default;
 $custom-file-height-inner:          $input-height-inner !default;
 $custom-file-focus-border-color:    $input-focus-border-color !default;
-$custom-file-focus-box-shadow:      $input-btn-focus-box-shadow !default;
+$custom-file-focus-box-shadow:      $input-focus-box-shadow !default;
+$custom-file-disabled-bg:           $input-disabled-bg !default;
 
-$custom-file-padding-y:             $input-btn-padding-y !default;
+$custom-file-padding-y:             $input-padding-y !default;
-$custom-file-padding-x:             $input-btn-padding-x !default;
+$custom-file-padding-x:             $input-padding-x !default;
-$custom-file-line-height:           $input-btn-line-height !default;
+$custom-file-line-height:           $input-line-height !default;
+$custom-file-font-family:           $input-font-family !default;
+$custom-file-font-weight:           $input-font-weight !default;
 $custom-file-color:                 $input-color !default;
 $custom-file-bg:                    $input-bg !default;
-$custom-file-border-width:          $input-btn-border-width !default;
+$custom-file-border-width:          $input-border-width !default;
 $custom-file-border-color:          $input-border-color !default;
 $custom-file-border-radius:         $input-border-radius !default;
 $custom-file-box-shadow:            $input-box-shadow !default;
@@ -547,40 +643,32 @@ $custom-file-text: (
 
 
 // Form validation
+
 $form-feedback-margin-top:          $form-text-margin-top !default;
 $form-feedback-font-size:           $small-font-size !default;
 $form-feedback-valid-color:         theme-color("success") !default;
 $form-feedback-invalid-color:       theme-color("danger") !default;
 
+$form-feedback-icon-valid-color:    $form-feedback-valid-color !default;
+$form-feedback-icon-valid:          str-replace(url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='#{$form-feedback-icon-valid-color}' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/%3e%3c/svg%3e"), "#", "%23") !default;
+$form-feedback-icon-invalid-color:  $form-feedback-invalid-color !default;
+$form-feedback-icon-invalid:        str-replace(url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='#{$form-feedback-icon-invalid-color}' viewBox='-2 -2 7 7'%3e%3cpath stroke='#{$form-feedback-icon-invalid-color}' d='M0 0l3 3m0-3L0 3'/%3e%3ccircle r='.5'/%3e%3ccircle cx='3' r='.5'/%3e%3ccircle cy='3' r='.5'/%3e%3ccircle cx='3' cy='3' r='.5'/%3e%3c/svg%3E"), "#", "%23") !default;
 
-// Dropdowns
+$form-validation-states: () !default;
-//
+// stylelint-disable-next-line scss/dollar-variable-default
-// Dropdown menu container and contents.
+$form-validation-states: map-merge(
-
+  (
-$dropdown-min-width:                10rem !default;
+    "valid": (
-$dropdown-padding-y:                .5rem !default;
+      "color": $form-feedback-valid-color,
-$dropdown-spacer:                   .125rem !default;
+      "icon": $form-feedback-icon-valid
-$dropdown-bg:                       $white !default;
+    ),
-$dropdown-border-color:             rgba($black, .15) !default;
+    "invalid": (
-$dropdown-border-radius:            $border-radius !default;
+      "color": $form-feedback-invalid-color,
-$dropdown-border-width:             $border-width !default;
+      "icon": $form-feedback-icon-invalid
-$dropdown-divider-bg:               $gray-200 !default;
+    ),
-$dropdown-box-shadow:               0 .5rem 1rem rgba($black, .175) !default;
+  ),
-
+  $form-validation-states
-$dropdown-link-color:               $gray-900 !default;
+);
-$dropdown-link-hover-color:         darken($gray-900, 5%) !default;
-$dropdown-link-hover-bg:            $gray-100 !default;
-
-$dropdown-link-active-color:        $component-active-color !default;
-$dropdown-link-active-bg:           $component-active-bg !default;
-
-$dropdown-link-disabled-color:      $gray-600 !default;
-
-$dropdown-item-padding-y:           .25rem !default;
-$dropdown-item-padding-x:           1.5rem !default;
-
-$dropdown-header-color:             $gray-600 !default;
-
 
 // Z-index master list
 //
@@ -595,6 +683,7 @@ $zindex-modal:                      1050 !default;
 $zindex-popover:                    1060 !default;
 $zindex-tooltip:                    1070 !default;
 
+
 // Navs
 
 $nav-link-padding-y:                .5rem !default;
@@ -614,18 +703,19 @@ $nav-pills-link-active-color:       $component-active-color !default;
 $nav-pills-link-active-bg:          $component-active-bg !default;
 
 $nav-divider-color:                 $gray-200 !default;
-$nav-divider-margin-y:              ($spacer / 2) !default;
+$nav-divider-margin-y:              $spacer / 2 !default;
+
 
 // Navbar
 
-$navbar-padding-y:                  ($spacer / 2) !default;
+$navbar-padding-y:                  $spacer / 2 !default;
 $navbar-padding-x:                  $spacer !default;
 
 $navbar-nav-link-padding-x:         .5rem !default;
 
 $navbar-brand-font-size:            $font-size-lg !default;
 // Compute the navbar-brand padding-y so the navbar-brand will have the same height as navbar-text and nav-link
-$nav-link-height:                   ($font-size-base * $line-height-base + $nav-link-padding-y * 2) !default;
+$nav-link-height:                   $font-size-base * $line-height-base + $nav-link-padding-y * 2 !default;
 $navbar-brand-height:               $navbar-brand-font-size * $line-height-base !default;
 $navbar-brand-padding-y:            ($nav-link-height - $navbar-brand-height) / 2 !default;
 
@@ -638,16 +728,55 @@ $navbar-dark-color:                 rgba($white, .5) !default;
 $navbar-dark-hover-color:           rgba($white, .75) !default;
 $navbar-dark-active-color:          $white !default;
 $navbar-dark-disabled-color:        rgba($white, .25) !default;
-$navbar-dark-toggler-icon-bg:       str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg viewBox='0 0 30 30' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath stroke='#{$navbar-dark-color}' stroke-width='2' stroke-linecap='round' stroke-miterlimit='10' d='M4 7h22M4 15h22M4 23h22'/%3E%3C/svg%3E"), "#", "%23") !default;
+$navbar-dark-toggler-icon-bg:       str-replace(url("data:image/svg+xml,%3csvg viewBox='0 0 30 30' xmlns='http://www.w3.org/2000/svg'%3e%3cpath stroke='#{$navbar-dark-color}' stroke-width='2' stroke-linecap='round' stroke-miterlimit='10' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e"), "#", "%23") !default;
 $navbar-dark-toggler-border-color:  rgba($white, .1) !default;
 
 $navbar-light-color:                rgba($black, .5) !default;
 $navbar-light-hover-color:          rgba($black, .7) !default;
 $navbar-light-active-color:         rgba($black, .9) !default;
 $navbar-light-disabled-color:       rgba($black, .3) !default;
-$navbar-light-toggler-icon-bg:      str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg viewBox='0 0 30 30' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath stroke='#{$navbar-light-color}' stroke-width='2' stroke-linecap='round' stroke-miterlimit='10' d='M4 7h22M4 15h22M4 23h22'/%3E%3C/svg%3E"), "#", "%23") !default;
+$navbar-light-toggler-icon-bg:      str-replace(url("data:image/svg+xml,%3csvg viewBox='0 0 30 30' xmlns='http://www.w3.org/2000/svg'%3e%3cpath stroke='#{$navbar-light-color}' stroke-width='2' stroke-linecap='round' stroke-miterlimit='10' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e"), "#", "%23") !default;
 $navbar-light-toggler-border-color: rgba($black, .1) !default;
 
+$navbar-light-brand-color:                $navbar-light-active-color !default;
+$navbar-light-brand-hover-color:          $navbar-light-active-color !default;
+$navbar-dark-brand-color:                 $navbar-dark-active-color !default;
+$navbar-dark-brand-hover-color:           $navbar-dark-active-color !default;
+
+
+// Dropdowns
+//
+// Dropdown menu container and contents.
+
+$dropdown-min-width:                10rem !default;
+$dropdown-padding-y:                .5rem !default;
+$dropdown-spacer:                   .125rem !default;
+$dropdown-font-size:                $font-size-base !default;
+$dropdown-color:                    $body-color !default;
+$dropdown-bg:                       $white !default;
+$dropdown-border-color:             rgba($black, .15) !default;
+$dropdown-border-radius:            $border-radius !default;
+$dropdown-border-width:             $border-width !default;
+$dropdown-inner-border-radius:      calc(#{$dropdown-border-radius} - #{$dropdown-border-width}) !default;
+$dropdown-divider-bg:               $gray-200 !default;
+$dropdown-divider-margin-y:         $nav-divider-margin-y !default;
+$dropdown-box-shadow:               0 .5rem 1rem rgba($black, .175) !default;
+
+$dropdown-link-color:               $gray-900 !default;
+$dropdown-link-hover-color:         darken($gray-900, 5%) !default;
+$dropdown-link-hover-bg:            $gray-100 !default;
+
+$dropdown-link-active-color:        $component-active-color !default;
+$dropdown-link-active-bg:           $component-active-bg !default;
+
+$dropdown-link-disabled-color:      $gray-600 !default;
+
+$dropdown-item-padding-y:           .25rem !default;
+$dropdown-item-padding-x:           1.5rem !default;
+
+$dropdown-header-color:             $gray-600 !default;
+
+
 // Pagination
 
 $pagination-padding-y:              .5rem !default;
@@ -682,6 +811,7 @@ $pagination-disabled-border-color:  $gray-300 !default;
 // Jumbotron
 
 $jumbotron-padding:                 2rem !default;
+$jumbotron-color:                   null !default;
 $jumbotron-bg:                      $gray-200 !default;
 
 
@@ -694,11 +824,13 @@ $card-border-radius:                $border-radius !default;
 $card-border-color:                 rgba($black, .125) !default;
 $card-inner-border-radius:          calc(#{$card-border-radius} - #{$card-border-width}) !default;
 $card-cap-bg:                       rgba($black, .03) !default;
+$card-cap-color:                    null !default;
+$card-color:                        null !default;
 $card-bg:                           $white !default;
 
 $card-img-overlay-padding:          1.25rem !default;
 
-$card-group-margin:                 ($grid-gutter-width / 2) !default;
+$card-group-margin:                 $grid-gutter-width / 2 !default;
 $card-deck-margin:                  $card-group-margin !default;
 
 $card-columns-count:                3 !default;
@@ -722,6 +854,14 @@ $tooltip-arrow-width:               .8rem !default;
 $tooltip-arrow-height:              .4rem !default;
 $tooltip-arrow-color:               $tooltip-bg !default;
 
+// Form tooltips must come after regular tooltips
+$form-feedback-tooltip-padding-y:     $tooltip-padding-y !default;
+$form-feedback-tooltip-padding-x:     $tooltip-padding-x !default;
+$form-feedback-tooltip-font-size:     $tooltip-font-size !default;
+$form-feedback-tooltip-line-height:   $line-height-base !default;
+$form-feedback-tooltip-opacity:       $tooltip-opacity !default;
+$form-feedback-tooltip-border-radius: $tooltip-border-radius !default;
+
 
 // Popovers
 
@@ -749,6 +889,24 @@ $popover-arrow-color:               $popover-bg !default;
 $popover-arrow-outer-color:         fade-in($popover-border-color, .05) !default;
 
 
+// Toasts
+
+$toast-max-width:                   350px !default;
+$toast-padding-x:                   .75rem !default;
+$toast-padding-y:                   .25rem !default;
+$toast-font-size:                   .875rem !default;
+$toast-color:                       null !default;
+$toast-background-color:            rgba($white, .85) !default;
+$toast-border-width:                1px !default;
+$toast-border-color:                rgba(0, 0, 0, .1) !default;
+$toast-border-radius:               .25rem !default;
+$toast-box-shadow:                  0 .25rem .75rem rgba($black, .1) !default;
+
+$toast-header-color:                $gray-600 !default;
+$toast-header-background-color:     rgba($white, .85) !default;
+$toast-header-border-color:         rgba(0, 0, 0, .05) !default;
+
+
 // Badges
 
 $badge-font-size:                   75% !default;
@@ -757,6 +915,9 @@ $badge-padding-y:                   .25em !default;
 $badge-padding-x:                   .4em !default;
 $badge-border-radius:               $border-radius !default;
 
+$badge-transition:                  $btn-transition !default;
+$badge-focus-width:                 $input-btn-focus-width !default;
+
 $badge-pill-padding-x:              .6em !default;
 // Use a higher than normal value to ensure completely rounded edges when
 // customizing padding or font-size on labels.
@@ -773,6 +934,7 @@ $modal-dialog-margin-y-sm-up:       1.75rem !default;
 
 $modal-title-line-height:           $line-height-base !default;
 
+$modal-content-color:               null !default;
 $modal-content-bg:                  $white !default;
 $modal-content-border-color:        rgba($black, .2) !default;
 $modal-content-border-width:        $border-width !default;
@@ -782,16 +944,21 @@ $modal-content-box-shadow-sm-up:    0 .5rem 1rem rgba($black, .5) !default;
 
 $modal-backdrop-bg:                 $black !default;
 $modal-backdrop-opacity:            .5 !default;
-$modal-header-border-color:         $gray-200 !default;
+$modal-header-border-color:         $border-color !default;
 $modal-footer-border-color:         $modal-header-border-color !default;
 $modal-header-border-width:         $modal-content-border-width !default;
 $modal-footer-border-width:         $modal-header-border-width !default;
-$modal-header-padding:              1rem !default;
+$modal-header-padding-y:            1rem !default;
+$modal-header-padding-x:            1rem !default;
+$modal-header-padding:              $modal-header-padding-y $modal-header-padding-x !default; // Keep this for backwards compatibility
 
+$modal-xl:                          1140px !default;
 $modal-lg:                          800px !default;
 $modal-md:                          500px !default;
 $modal-sm:                          300px !default;
 
+$modal-fade-transform:              translate(0, -50px) !default;
+$modal-show-transform:              none !default;
 $modal-transition:                  transform .3s ease-out !default;
 
 
@@ -814,7 +981,7 @@ $alert-color-level:                 6 !default;
 // Progress bars
 
 $progress-height:                   1rem !default;
-$progress-font-size:                ($font-size-base * .75) !default;
+$progress-font-size:                $font-size-base * .75 !default;
 $progress-bg:                       $gray-200 !default;
 $progress-border-radius:            $border-radius !default;
 $progress-box-shadow:               inset 0 .1rem .1rem rgba($black, .1) !default;
@@ -823,8 +990,10 @@ $progress-bar-bg:                   theme-color("primary") !default;
 $progress-bar-animation-timing:     1s linear infinite !default;
 $progress-bar-transition:           width .6s ease !default;
 
+
 // List group
 
+$list-group-color:                  null !default;
 $list-group-bg:                     $white !default;
 $list-group-border-color:           rgba($black, .125) !default;
 $list-group-border-width:           $border-width !default;
@@ -882,24 +1051,40 @@ $breadcrumb-border-radius:          $border-radius !default;
 
 // Carousel
 
-$carousel-control-color:            $white !default;
+$carousel-control-color:             $white !default;
-$carousel-control-width:            15% !default;
+$carousel-control-width:             15% !default;
-$carousel-control-opacity:          .5 !default;
+$carousel-control-opacity:           .5 !default;
+$carousel-control-hover-opacity:     .9 !default;
+$carousel-control-transition:        opacity .15s ease !default;
 
-$carousel-indicator-width:          30px !default;
+$carousel-indicator-width:           30px !default;
-$carousel-indicator-height:         3px !default;
+$carousel-indicator-height:          3px !default;
-$carousel-indicator-spacer:         3px !default;
+$carousel-indicator-hit-area-height: 10px !default;
-$carousel-indicator-active-bg:      $white !default;
+$carousel-indicator-spacer:          3px !default;
+$carousel-indicator-active-bg:       $white !default;
+$carousel-indicator-transition:      opacity .6s ease !default;
 
-$carousel-caption-width:            70% !default;
+$carousel-caption-width:             70% !default;
-$carousel-caption-color:            $white !default;
+$carousel-caption-color:             $white !default;
 
-$carousel-control-icon-width:       20px !default;
+$carousel-control-icon-width:        20px !default;
 
-$carousel-control-prev-icon-bg:     str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='#{$carousel-control-color}' viewBox='0 0 8 8'%3E%3Cpath d='M5.25 0l-4 4 4 4 1.5-1.5-2.5-2.5 2.5-2.5-1.5-1.5z'/%3E%3C/svg%3E"), "#", "%23") !default;
+$carousel-control-prev-icon-bg:      str-replace(url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='#{$carousel-control-color}' viewBox='0 0 8 8'%3e%3cpath d='M5.25 0l-4 4 4 4 1.5-1.5-2.5-2.5 2.5-2.5-1.5-1.5z'/%3e%3c/svg%3e"), "#", "%23") !default;
-$carousel-control-next-icon-bg:     str-replace(url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='#{$carousel-control-color}' viewBox='0 0 8 8'%3E%3Cpath d='M2.75 0l-1.5 1.5 2.5 2.5-2.5 2.5 1.5 1.5 4-4-4-4z'/%3E%3C/svg%3E"), "#", "%23") !default;
+$carousel-control-next-icon-bg:      str-replace(url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='#{$carousel-control-color}' viewBox='0 0 8 8'%3e%3cpath d='M2.75 0l-1.5 1.5 2.5 2.5-2.5 2.5 1.5 1.5 4-4-4-4z'/%3e%3c/svg%3e"), "#", "%23") !default;
 
-$carousel-transition:               transform .6s ease !default; // Define transform transition first if using multiple transitions (e.g., `transform 2s ease, opacity .5s ease-out`)
+$carousel-transition-duration:       .6s !default;
+$carousel-transition:                transform $carousel-transition-duration ease-in-out !default; // Define transform transition first if using multiple transitions (e.g., `transform 2s ease, opacity .5s ease-out`)
+
+
+// Spinners
+
+$spinner-width:         2rem !default;
+$spinner-height:        $spinner-width !default;
+$spinner-border-width:  .25em !default;
+
+$spinner-width-sm:        1rem !default;
+$spinner-height-sm:       $spinner-width-sm !default;
+$spinner-border-width-sm: .2em !default;
 
 
 // Close
@@ -909,6 +1094,7 @@ $close-font-weight:                 $font-weight-bold !default;
 $close-color:                       $black !default;
 $close-text-shadow:                 0 1px 0 $white !default;
 
+
 // Code
 
 $code-font-size:                    87.5% !default;
@@ -924,6 +1110,14 @@ $pre-color:                         $gray-900 !default;
 $pre-scrollable-max-height:         340px !default;
 
 
+// Utilities
+
+$displays: none, inline, inline-block, block, table, table-row, table-cell, flex, inline-flex !default;
+$overflows: auto, hidden !default;
+$positions: static, relative, absolute, fixed, sticky !default;
+
+
 // Printing
+
 $print-page-size:                   a3 !default;
 $print-body-min-width:              map-get($grid-breakpoints, "lg") !default;

static/src/bootstrap/scss/bootstrap-grid.scss

@@ -1,14 +1,10 @@
 /*!
- * Bootstrap Grid v4.1.1 (https://getbootstrap.com/)
+ * Bootstrap Grid v4.3.1 (https://getbootstrap.com/)
- * Copyright 2011-2018 The Bootstrap Authors
+ * Copyright 2011-2019 The Bootstrap Authors
- * Copyright 2011-2018 Twitter, Inc.
+ * Copyright 2011-2019 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 
-@at-root {
-  @-ms-viewport { width: device-width; } // stylelint-disable-line at-rule-no-vendor-prefix
-}
-
 html {
   box-sizing: border-box;
   -ms-overflow-style: scrollbar;
@@ -30,3 +26,4 @@ html {
 @import "grid";
 @import "utilities/display";
 @import "utilities/flex";
+@import "utilities/spacing";

static/src/bootstrap/scss/bootstrap-reboot.scss

@@ -1,7 +1,7 @@
 /*!
- * Bootstrap Reboot v4.1.1 (https://getbootstrap.com/)
+ * Bootstrap Reboot v4.3.1 (https://getbootstrap.com/)
- * Copyright 2011-2018 The Bootstrap Authors
+ * Copyright 2011-2019 The Bootstrap Authors
- * Copyright 2011-2018 Twitter, Inc.
+ * 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)
  */

static/src/bootstrap/scss/bootstrap.scss

@@ -1,7 +1,7 @@
 /*!
- * Bootstrap v4.1.1 (https://getbootstrap.com/)
+ * Bootstrap v4.3.1 (https://getbootstrap.com/)
- * Copyright 2011-2018 The Bootstrap Authors
+ * Copyright 2011-2019 The Bootstrap Authors
- * Copyright 2011-2018 Twitter, Inc.
+ * Copyright 2011-2019 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 
@@ -34,9 +34,11 @@
 @import "media";
 @import "list-group";
 @import "close";
+@import "toasts";
 @import "modal";
 @import "tooltip";
 @import "popover";
 @import "carousel";
+@import "spinners";
 @import "utilities";
 @import "print";

static/src/bootstrap/scss/mixins/_badge.scss

@@ -2,11 +2,16 @@
   color: color-yiq($bg);
   background-color: $bg;
 
-  &[href] {
+  @at-root a#{&} {
     @include hover-focus {
       color: color-yiq($bg);
-      text-decoration: none;
       background-color: darken($bg, 10%);
     }
+
+    &:focus,
+    &.focus {
+      outline: 0;
+      box-shadow: 0 0 0 $badge-focus-width rgba($bg, .5);
+    }
   }
 }

static/src/bootstrap/scss/mixins/_border-radius.scss

@@ -1,9 +1,13 @@
+// stylelint-disable property-blacklist
 // Single side border-radius
 
-@mixin border-radius($radius: $border-radius) {
+@mixin border-radius($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) {
@@ -33,3 +37,27 @@
     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;
+  }
+}

static/src/bootstrap/scss/mixins/_box-shadow.scss

@@ -1,5 +1,20 @@
 @mixin box-shadow($shadow...) {
   @if $enable-shadows {
-    box-shadow: $shadow;
+    $result: ();
+
+    @if (length($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;
+    }
   }
 }

static/src/bootstrap/scss/mixins/_breakpoints.scss

@@ -16,7 +16,7 @@
 //    md
 @function breakpoint-next($name, $breakpoints: $grid-breakpoints, $breakpoint-names: map-keys($breakpoints)) {
   $n: index($breakpoint-names, $name);
-  @return if($n < length($breakpoint-names), nth($breakpoint-names, $n + 1), null);
+  @return if($n != null and $n < length($breakpoint-names), nth($breakpoint-names, $n + 1), null);
 }
 
 // Minimum breakpoint width. Null for the smallest (first) breakpoint.
@@ -39,10 +39,10 @@
 //    767.98px
 @function breakpoint-max($name, $breakpoints: $grid-breakpoints) {
   $next: breakpoint-next($name, $breakpoints);
-  @return if($next, breakpoint-min($next, $breakpoints) - .02px, null);
+  @return if($next, breakpoint-min($next, $breakpoints) - .02, null);
 }
 
-// Returns a blank string if smallest breakpoint, otherwise returns the name with a dash infront.
+// 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))

static/src/bootstrap/scss/mixins/_buttons.scss

@@ -19,9 +19,9 @@
   &.focus {
     // Avoid using mixin so we can pass custom focus shadow properly
     @if $enable-shadows {
-      box-shadow: $btn-box-shadow, 0 0 0 $btn-focus-width rgba($border, .5);
+      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 $btn-focus-width rgba($border, .5);
+      box-shadow: 0 0 0 $btn-focus-width rgba(mix(color-yiq($background), $border, 15%), .5);
     }
   }
 
@@ -31,6 +31,10 @@
     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,
@@ -45,10 +49,10 @@
 
     &:focus {
       // Avoid using mixin so we can pass custom focus shadow properly
-      @if $enable-shadows {
+      @if $enable-shadows and $btn-active-box-shadow != none {
-        box-shadow: $btn-active-box-shadow, 0 0 0 $btn-focus-width rgba($border, .5);
+        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 $btn-focus-width rgba($border, .5);
+        box-shadow: 0 0 0 $btn-focus-width rgba(mix(color-yiq($background), $border, 15%), .5);
       }
     }
   }
@@ -56,11 +60,9 @@
 
 @mixin button-outline-variant($color, $color-hover: color-yiq($color), $active-background: $color, $active-border: $color) {
   color: $color;
-  background-color: transparent;
-  background-image: none;
   border-color: $color;
 
-  &:hover {
+  @include hover {
     color: $color-hover;
     background-color: $active-background;
     border-color: $active-border;
@@ -98,12 +100,8 @@
 // Button sizes
 @mixin button-size($padding-y, $padding-x, $font-size, $line-height, $border-radius) {
   padding: $padding-y $padding-x;
-  font-size: $font-size;
+  @include font-size($font-size);
   line-height: $line-height;
   // Manually declare to provide an override to the browser default
-  @if $enable-rounded {
+  @include border-radius($border-radius, 0);
-    border-radius: $border-radius;
-  } @else {
-    border-radius: 0;
-  }
 }

static/src/bootstrap/scss/mixins/_caret.scss

@@ -29,10 +29,8 @@
   @if $enable-caret {
     &::after {
       display: inline-block;
-      width: 0;
+      margin-left: $caret-spacing;
-      height: 0;
+      vertical-align: $caret-vertical-align;
-      margin-left: $caret-width * .85;
-      vertical-align: $caret-width * .85;
       content: "";
       @if $direction == down {
         @include caret-down;
@@ -50,10 +48,8 @@
 
       &::before {
         display: inline-block;
-        width: 0;
+        margin-right: $caret-spacing;
-        height: 0;
+        vertical-align: $caret-vertical-align;
-        margin-right: $caret-width * .85;
-        vertical-align: $caret-width * .85;
         content: "";
         @include caret-left;
       }

static/src/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}.";
+  }
+}

static/src/bootstrap/scss/mixins/_float.scss

@@ -2,10 +2,13 @@
 
 @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");
 }

static/src/bootstrap/scss/mixins/_forms.scss

@@ -26,12 +26,12 @@
 }
 
 
-@mixin form-validation-state($state, $color) {
+@mixin form-validation-state($state, $color, $icon) {
   .#{$state}-feedback {
     display: none;
     width: 100%;
     margin-top: $form-feedback-margin-top;
-    font-size: $form-feedback-font-size;
+    @include font-size($form-feedback-font-size);
     color: $color;
   }
 
@@ -41,21 +41,28 @@
     z-index: 5;
     display: none;
     max-width: 100%; // Contain to parent when possible
-    padding: .5rem;
+    padding: $form-feedback-tooltip-padding-y $form-feedback-tooltip-padding-x;
     margin-top: .1rem;
-    font-size: .875rem;
+    @include font-size($form-feedback-tooltip-font-size);
-    line-height: 1;
+    line-height: $form-feedback-tooltip-line-height;
-    color: $white;
+    color: color-yiq($color);
-    background-color: rgba($color, .8);
+    background-color: rgba($color, $form-feedback-tooltip-opacity);
-    border-radius: .2rem;
+    @include border-radius($form-feedback-tooltip-border-radius);
   }
 
-  .form-control,
+  .form-control {
-  .custom-select {
     .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);
@@ -68,6 +75,40 @@
     }
   }
 
+  // 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} {
@@ -99,7 +140,7 @@
         color: $color;
 
         &::before {
-          background-color: lighten($color, 25%);
+          border-color: $color;
         }
       }
 
@@ -110,13 +151,18 @@
 
       &: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 1px $body-bg, 0 0 0 $input-focus-width rgba($color, .25);
+          box-shadow: 0 0 0 $input-focus-width rgba($color, .25);
+        }
+
+        &:not(:checked) ~ .custom-control-label::before {
+          border-color: $color;
         }
       }
     }
@@ -128,8 +174,6 @@
     &.is-#{$state} {
       ~ .custom-file-label {
         border-color: $color;
-
-        &::before { border-color: inherit; }
       }
 
       ~ .#{$state}-feedback,
@@ -139,6 +183,7 @@
 
       &:focus {
         ~ .custom-file-label {
+          border-color: $color;
           box-shadow: 0 0 0 $input-focus-width rgba($color, .25);
         }
       }

static/src/bootstrap/scss/mixins/_grid-framework.scss

@@ -8,9 +8,8 @@
   %grid-column {
     position: relative;
     width: 100%;
-    min-height: 1px; // Prevent columns from collapsing when empty
+    padding-right: $gutter / 2;
-    padding-right: ($gutter / 2);
+    padding-left: $gutter / 2;
-    padding-left: ($gutter / 2);
   }
 
   @each $breakpoint in map-keys($breakpoints) {
@@ -37,7 +36,7 @@
       .col#{$infix}-auto {
         flex: 0 0 auto;
         width: auto;
-        max-width: none; // Reset earlier grid tiers
+        max-width: 100%; // Reset earlier grid tiers
       }
 
       @for $i from 1 through $columns {

static/src/bootstrap/scss/mixins/_grid.scss

@@ -2,10 +2,10 @@
 //
 // Generate semantic grid columns with these mixins.
 
-@mixin make-container() {
+@mixin make-container($gutter: $grid-gutter-width) {
   width: 100%;
-  padding-right: ($grid-gutter-width / 2);
+  padding-right: $gutter / 2;
-  padding-left: ($grid-gutter-width / 2);
+  padding-left: $gutter / 2;
   margin-right: auto;
   margin-left: auto;
 }
@@ -20,22 +20,21 @@
   }
 }
 
-@mixin make-row() {
+@mixin make-row($gutter: $grid-gutter-width) {
   display: flex;
   flex-wrap: wrap;
-  margin-right: ($grid-gutter-width / -2);
+  margin-right: -$gutter / 2;
-  margin-left: ($grid-gutter-width / -2);
+  margin-left: -$gutter / 2;
 }
 
-@mixin make-col-ready() {
+@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%;
-  min-height: 1px; // Prevent collapsing
+  padding-right: $gutter / 2;
-  padding-right: ($grid-gutter-width / 2);
+  padding-left: $gutter / 2;
-  padding-left: ($grid-gutter-width / 2);
 }
 
 @mixin make-col($size, $columns: $grid-columns) {

static/src/bootstrap/scss/mixins/_hover.scss

@@ -1,6 +1,6 @@
 // Hover mixin and `$enable-hover-media-query` are deprecated.
 //
-// Origally added during our alphas and maintained during betas, this mixin was
+// 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.
 //

static/src/bootstrap/scss/mixins/_image.scss

@@ -20,7 +20,6 @@
 //
 // Short retina mixin for setting background-image and -size.
 
-// stylelint-disable indentation, media-query-list-comma-newline-after
 @mixin img-retina($file-1x, $file-2x, $width-1x, $height-1x) {
   background-image: url($file-1x);
 
@@ -29,8 +28,9 @@
   // 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
+    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");
 }

static/src/bootstrap/scss/mixins/_pagination.scss

@@ -3,7 +3,7 @@
 @mixin pagination-size($padding-y, $padding-x, $font-size, $line-height, $border-radius) {
   .page-link {
     padding: $padding-y $padding-x;
-    font-size: $font-size;
+    @include font-size($font-size);
     line-height: $line-height;
   }
 

static/src/bootstrap/scss/mixins/_reset-text.scss

@@ -5,7 +5,7 @@
   font-weight: $font-weight-normal;
   line-height: $line-height-base;
   text-align: left; // Fallback for where `start` is not supported
-  text-align: start; // stylelint-disable-line declaration-block-no-duplicate-properties
+  text-align: start;
   text-decoration: none;
   text-shadow: none;
   text-transform: none;

static/src/bootstrap/scss/mixins/_size.scss

@@ -3,4 +3,5 @@
 @mixin size($width, $height: $width) {
   width: $width;
   height: $height;
+  @include deprecate("`size()`", "v4.3.0", "v5");
 }

static/src/bootstrap/scss/mixins/_table-row.scss

@@ -1,6 +1,6 @@
 // Tables
 
-@mixin table-row-variant($state, $background) {
+@mixin table-row-variant($state, $background, $border: null) {
   // Exact selectors below required to override `.table-striped` and prevent
   // inheritance to nested tables.
   .table-#{$state} {
@@ -9,6 +9,15 @@
     > td {
       background-color: $background;
     }
+
+    @if $border != null {
+      th,
+      td,
+      thead th,
+      tbody + tbody {
+        border-color: $border;
+      }
+    }
   }
 
   // Hover states for `.table-hover`

static/src/bootstrap/scss/mixins/_text-emphasis.scss

@@ -6,9 +6,11 @@
   #{$parent} {
     color: $color !important;
   }
-  a#{$parent} {
+  @if $emphasized-link-hover-darken-percentage != 0 {
-    @include hover-focus {
+    a#{$parent} {
-      color: darken($color, 10%) !important;
+      @include hover-focus {
+        color: darken($color, $emphasized-link-hover-darken-percentage) !important;
+      }
     }
   }
 }

static/src/bootstrap/scss/mixins/_text-hide.scss

@@ -7,7 +7,5 @@
   background-color: transparent;
   border: 0;
 
-  @if ($ignore-warning != true) {
+  @include deprecate("`text-hide()`", "v4.1.0", "v5", $ignore-warning);
-    @warn "The `text-hide()` mixin has been deprecated as of v4.1.0. It will be removed entirely in v5.";
-  }
 }

static/src/bootstrap/scss/mixins/_transition.scss

@@ -1,3 +1,4 @@
+// stylelint-disable property-blacklist
 @mixin transition($transition...) {
   @if $enable-transitions {
     @if length($transition) == 0 {
@@ -7,7 +8,9 @@
     }
   }
 
-  @media screen and (prefers-reduced-motion: reduce) {
+  @if $enable-prefers-reduced-motion-media-query {
-    transition: none;
+    @media (prefers-reduced-motion: reduce) {
+      transition: none;
+    }
   }
 }

static/src/bootstrap/scss/mixins/_visibility.scss

@@ -4,4 +4,5 @@
 
 @mixin invisible($visibility) {
   visibility: $visibility !important;
+  @include deprecate("`invisible()`", "v4.3.0", "v5");
 }

static/src/bootstrap/scss/utilities/_borders.scss

@@ -1,4 +1,4 @@
-// stylelint-disable declaration-no-important
+// stylelint-disable property-blacklist, declaration-no-important
 
 //
 // Border
@@ -30,30 +30,46 @@
 // Border-radius
 //
 
+.rounded-sm {
+  border-radius: $border-radius-sm !important;
+}
+
 .rounded {
   border-radius: $border-radius !important;
 }
+
 .rounded-top {
   border-top-left-radius: $border-radius !important;
   border-top-right-radius: $border-radius !important;
 }
+
 .rounded-right {
   border-top-right-radius: $border-radius !important;
   border-bottom-right-radius: $border-radius !important;
 }
+
 .rounded-bottom {
   border-bottom-right-radius: $border-radius !important;
   border-bottom-left-radius: $border-radius !important;
 }
+
 .rounded-left {
   border-top-left-radius: $border-radius !important;
   border-bottom-left-radius: $border-radius !important;
 }
 
+.rounded-lg {
+  border-radius: $border-radius-lg !important;
+}
+
 .rounded-circle {
   border-radius: 50% !important;
 }
 
+.rounded-pill {
+  border-radius: $rounded-pill !important;
+}
+
 .rounded-0 {
   border-radius: 0 !important;
 }

static/src/bootstrap/scss/utilities/_display.scss

@@ -8,15 +8,9 @@
   @include media-breakpoint-up($breakpoint) {
     $infix: breakpoint-infix($breakpoint, $grid-breakpoints);
 
-    .d#{$infix}-none         { display: none !important; }
+    @each $value in $displays {
-    .d#{$infix}-inline       { display: inline !important; }
+      .d#{$infix}-#{$value} { display: $value !important; }
-    .d#{$infix}-inline-block { display: inline-block !important; }
+    }
-    .d#{$infix}-block        { display: block !important; }
-    .d#{$infix}-table        { display: table !important; }
-    .d#{$infix}-table-row    { display: table-row !important; }
-    .d#{$infix}-table-cell   { display: table-cell !important; }
-    .d#{$infix}-flex         { display: flex !important; }
-    .d#{$infix}-inline-flex  { display: inline-flex !important; }
   }
 }
 
@@ -26,13 +20,7 @@
 //
 
 @media print {
-  .d-print-none         { display: none !important; }
+  @each $value in $displays {
-  .d-print-inline       { display: inline !important; }
+    .d-print-#{$value} { display: $value !important; }
-  .d-print-inline-block { display: inline-block !important; }
+  }
-  .d-print-block        { display: block !important; }
-  .d-print-table        { display: table !important; }
-  .d-print-table-row    { display: table-row !important; }
-  .d-print-table-cell   { display: table-cell !important; }
-  .d-print-flex         { display: flex !important; }
-  .d-print-inline-flex  { display: inline-flex !important; }
 }

static/src/bootstrap/scss/utilities/_embed.scss

@@ -27,26 +27,13 @@
   }
 }
 
-.embed-responsive-21by9 {
+@each $embed-responsive-aspect-ratio in $embed-responsive-aspect-ratios {
-  &::before {
+  $embed-responsive-aspect-ratio-x: nth($embed-responsive-aspect-ratio, 1);
-    padding-top: percentage(9 / 21);
+  $embed-responsive-aspect-ratio-y: nth($embed-responsive-aspect-ratio, 2);
-  }
-}
 
-.embed-responsive-16by9 {
+  .embed-responsive-#{$embed-responsive-aspect-ratio-x}by#{$embed-responsive-aspect-ratio-y} {
-  &::before {
+    &::before {
-    padding-top: percentage(9 / 16);
+      padding-top: percentage($embed-responsive-aspect-ratio-y / $embed-responsive-aspect-ratio-x);
-  }
+    }
-}
-
-.embed-responsive-4by3 {
-  &::before {
-    padding-top: percentage(3 / 4);
-  }
-}
-
-.embed-responsive-1by1 {
-  &::before {
-    padding-top: percentage(1 / 1);
   }
 }

static/src/bootstrap/scss/utilities/_float.scss

@@ -1,9 +1,11 @@
+// stylelint-disable declaration-no-important
+
 @each $breakpoint in map-keys($grid-breakpoints) {
   @include media-breakpoint-up($breakpoint) {
     $infix: breakpoint-infix($breakpoint, $grid-breakpoints);
 
-    .float#{$infix}-left  { @include float-left; }
+    .float#{$infix}-left  { float: left !important; }
-    .float#{$infix}-right { @include float-right; }
+    .float#{$infix}-right { float: right !important; }
-    .float#{$infix}-none  { @include float-none; }
+    .float#{$infix}-none  { float: none !important; }
   }
 }

static/src/bootstrap/scss/utilities/_overflow.scss

@@ -0,0 +1,5 @@
+// stylelint-disable declaration-no-important
+
+@each $value in $overflows {
+  .overflow-#{$value} { overflow: $value !important; }
+}

static/src/bootstrap/scss/utilities/_position.scss

@@ -1,11 +1,6 @@
 // stylelint-disable declaration-no-important
 
 // Common values
-
-// Sass list not in variables since it's not intended for customization.
-// stylelint-disable-next-line scss/dollar-variable-default
-$positions: static, relative, absolute, fixed, sticky;
-
 @each $position in $positions {
   .position-#{$position} { position: $position !important; }
 }

static/src/bootstrap/scss/utilities/_sizing.scss

@@ -10,3 +10,11 @@
 
 .mw-100 { max-width: 100% !important; }
 .mh-100 { max-height: 100% !important; }
+
+// Viewport additional helpers
+
+.min-vw-100 { min-width: 100vw !important; }
+.min-vh-100 { min-height: 100vh !important; }
+
+.vw-100 { width: 100vw !important; }
+.vh-100 { height: 100vh !important; }

static/src/bootstrap/scss/utilities/_spacing.scss

@@ -8,7 +8,6 @@
 
     @each $prop, $abbrev in (margin: m, padding: p) {
       @each $size, $length in $spacers {
-
         .#{$abbrev}#{$infix}-#{$size} { #{$prop}: $length !important; }
         .#{$abbrev}t#{$infix}-#{$size},
         .#{$abbrev}y#{$infix}-#{$size} {
@@ -29,6 +28,29 @@
       }
     }
 
+    // Negative margins (e.g., where `.mb-n1` is negative version of `.mb-1`)
+    @each $size, $length in $spacers {
+      @if $size != 0 {
+        .m#{$infix}-n#{$size} { margin: -$length !important; }
+        .mt#{$infix}-n#{$size},
+        .my#{$infix}-n#{$size} {
+          margin-top: -$length !important;
+        }
+        .mr#{$infix}-n#{$size},
+        .mx#{$infix}-n#{$size} {
+          margin-right: -$length !important;
+        }
+        .mb#{$infix}-n#{$size},
+        .my#{$infix}-n#{$size} {
+          margin-bottom: -$length !important;
+        }
+        .ml#{$infix}-n#{$size},
+        .mx#{$infix}-n#{$size} {
+          margin-left: -$length !important;
+        }
+      }
+    }
+
     // Some special margin utils
     .m#{$infix}-auto { margin: auto !important; }
     .mt#{$infix}-auto,

static/src/bootstrap/scss/utilities/_stretched-link.scss

@@ -0,0 +1,19 @@
+//
+// Stretched link
+//
+
+.stretched-link {
+  &::after {
+    position: absolute;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    z-index: 1;
+    // Just in case `pointer-events: none` is set on a parent
+    pointer-events: auto;
+    content: "";
+    // IE10 bugfix, see https://stackoverflow.com/questions/16947967/ie10-hover-pseudo-class-doesnt-work-without-background-color
+    background-color: rgba(0, 0, 0, 0);
+  }
+}

static/src/bootstrap/scss/utilities/_text.scss

@@ -4,11 +4,12 @@
 // Text
 //
 
-.text-monospace { font-family: $font-family-monospace; }
+.text-monospace { font-family: $font-family-monospace !important; }
 
 // Alignment
 
 .text-justify  { text-align: justify !important; }
+.text-wrap     { white-space: normal !important; }
 .text-nowrap   { white-space: nowrap !important; }
 .text-truncate { @include text-truncate; }
 
@@ -32,10 +33,12 @@
 
 // Weight and italics
 
-.font-weight-light  { font-weight: $font-weight-light !important; }
+.font-weight-light   { font-weight: $font-weight-light !important; }
-.font-weight-normal { font-weight: $font-weight-normal !important; }
+.font-weight-lighter { font-weight: $font-weight-lighter !important; }
-.font-weight-bold   { font-weight: $font-weight-bold !important; }
+.font-weight-normal  { font-weight: $font-weight-normal !important; }
-.font-italic        { font-style: italic !important; }
+.font-weight-bold    { font-weight: $font-weight-bold !important; }
+.font-weight-bolder  { font-weight: $font-weight-bolder !important; }
+.font-italic         { font-style: italic !important; }
 
 // Contextual colors
 
@@ -56,3 +59,14 @@
 .text-hide {
   @include text-hide($ignore-warning: true);
 }
+
+.text-decoration-none { text-decoration: none !important; }
+
+.text-break {
+  word-break: break-word !important; // IE & < Edge 18
+  overflow-wrap: break-word !important;
+}
+
+// Reset
+
+.text-reset { color: inherit !important; }

static/src/bootstrap/scss/utilities/_visibility.scss

@@ -1,11 +1,13 @@
+// stylelint-disable declaration-no-important
+
 //
 // Visibility utilities
 //
 
 .visible {
-  @include invisible(visible);
+  visibility: visible !important;
 }
 
 .invisible {
-  @include invisible(hidden);
+  visibility: hidden !important;
 }

static/src/bootstrap/scss/vendor/_rfs.scss

@@ -0,0 +1,204 @@
+// stylelint-disable property-blacklist, scss/dollar-variable-default
+
+// SCSS RFS mixin
+//
+// Automated font-resizing
+//
+// See https://github.com/twbs/rfs
+
+// Configuration
+
+// Base font size
+$rfs-base-font-size: 1.25rem !default;
+$rfs-font-size-unit: rem !default;
+
+// Breakpoint at where font-size starts decreasing if screen width is smaller
+$rfs-breakpoint: 1200px !default;
+$rfs-breakpoint-unit: px !default;
+
+// Resize font-size based on screen height and width
+$rfs-two-dimensional: false !default;
+
+// Factor of decrease
+$rfs-factor: 10 !default;
+
+@if type-of($rfs-factor) != "number" or $rfs-factor <= 1 {
+  @error "`#{$rfs-factor}` is not a valid  $rfs-factor, it must be greater than 1.";
+}
+
+// Generate enable or disable classes. Possibilities: false, "enable" or "disable"
+$rfs-class: false !default;
+
+// 1 rem = $rfs-rem-value px
+$rfs-rem-value: 16 !default;
+
+// Safari iframe resize bug: https://github.com/twbs/rfs/issues/14
+$rfs-safari-iframe-resize-bug-fix: false !default;
+
+// Disable RFS by setting $enable-responsive-font-sizes to false
+$enable-responsive-font-sizes: true !default;
+
+// Cache $rfs-base-font-size unit
+$rfs-base-font-size-unit: unit($rfs-base-font-size);
+
+// Remove px-unit from $rfs-base-font-size for calculations
+@if $rfs-base-font-size-unit == "px" {
+  $rfs-base-font-size: $rfs-base-font-size / ($rfs-base-font-size * 0 + 1);
+}
+@else if $rfs-base-font-size-unit == "rem" {
+  $rfs-base-font-size: $rfs-base-font-size / ($rfs-base-font-size * 0 + 1 / $rfs-rem-value);
+}
+
+// Cache $rfs-breakpoint unit to prevent multiple calls
+$rfs-breakpoint-unit-cache: unit($rfs-breakpoint);
+
+// Remove unit from $rfs-breakpoint for calculations
+@if $rfs-breakpoint-unit-cache == "px" {
+  $rfs-breakpoint: $rfs-breakpoint / ($rfs-breakpoint * 0 + 1);
+}
+@else if $rfs-breakpoint-unit-cache == "rem" or $rfs-breakpoint-unit-cache == "em" {
+  $rfs-breakpoint: $rfs-breakpoint / ($rfs-breakpoint * 0 + 1 / $rfs-rem-value);
+}
+
+// Responsive font-size mixin
+@mixin rfs($fs, $important: false) {
+  // Cache $fs unit
+  $fs-unit: if(type-of($fs) == "number", unit($fs), false);
+
+  // Add !important suffix if needed
+  $rfs-suffix: if($important, " !important", "");
+
+  // If $fs isn't a number (like inherit) or $fs has a unit (not px or rem, like 1.5em) or $ is 0, just print the value
+  @if not $fs-unit or $fs-unit != "" and $fs-unit != "px" and $fs-unit != "rem" or $fs == 0 {
+    font-size: #{$fs}#{$rfs-suffix};
+  }
+  @else {
+    // Variables for storing static and fluid rescaling
+    $rfs-static: null;
+    $rfs-fluid: null;
+
+    // Remove px-unit from $fs for calculations
+    @if $fs-unit == "px" {
+      $fs: $fs / ($fs * 0 + 1);
+    }
+    @else if $fs-unit == "rem" {
+      $fs: $fs / ($fs * 0 + 1 / $rfs-rem-value);
+    }
+
+    // Set default font-size
+    @if $rfs-font-size-unit == rem {
+      $rfs-static: #{$fs / $rfs-rem-value}rem#{$rfs-suffix};
+    }
+    @else if $rfs-font-size-unit == px {
+      $rfs-static: #{$fs}px#{$rfs-suffix};
+    }
+    @else {
+      @error "`#{$rfs-font-size-unit}` is not a valid unit for $rfs-font-size-unit. Use `px` or `rem`.";
+    }
+
+    // Only add media query if font-size is bigger as the minimum font-size
+    // If $rfs-factor == 1, no rescaling will take place
+    @if $fs > $rfs-base-font-size and $enable-responsive-font-sizes {
+      $min-width: null;
+      $variable-unit: null;
+
+      // Calculate minimum font-size for given font-size
+      $fs-min: $rfs-base-font-size + ($fs - $rfs-base-font-size) / $rfs-factor;
+
+      // Calculate difference between given font-size and minimum font-size for given font-size
+      $fs-diff: $fs - $fs-min;
+
+      // Base font-size formatting
+      // No need to check if the unit is valid, because we did that before
+      $min-width: if($rfs-font-size-unit == rem, #{$fs-min / $rfs-rem-value}rem, #{$fs-min}px);
+
+      // If two-dimensional, use smallest of screen width and height
+      $variable-unit: if($rfs-two-dimensional, vmin, vw);
+
+      // Calculate the variable width between 0 and $rfs-breakpoint
+      $variable-width: #{$fs-diff * 100 / $rfs-breakpoint}#{$variable-unit};
+
+      // Set the calculated font-size.
+      $rfs-fluid: calc(#{$min-width} + #{$variable-width}) #{$rfs-suffix};
+    }
+
+    // Rendering
+    @if $rfs-fluid == null {
+      // Only render static font-size if no fluid font-size is available
+      font-size: $rfs-static;
+    }
+    @else {
+      $mq-value: null;
+
+      // RFS breakpoint formatting
+      @if $rfs-breakpoint-unit == em or $rfs-breakpoint-unit == rem {
+        $mq-value: #{$rfs-breakpoint / $rfs-rem-value}#{$rfs-breakpoint-unit};
+      }
+      @else if $rfs-breakpoint-unit == px {
+        $mq-value: #{$rfs-breakpoint}px;
+      }
+      @else {
+        @error "`#{$rfs-breakpoint-unit}` is not a valid unit for $rfs-breakpoint-unit. Use `px`, `em` or `rem`.";
+      }
+
+      @if $rfs-class == "disable" {
+        // Adding an extra class increases specificity,
+        // which prevents the media query to override the font size
+        &,
+        .disable-responsive-font-size &,
+        &.disable-responsive-font-size {
+          font-size: $rfs-static;
+        }
+      }
+      @else {
+        font-size: $rfs-static;
+      }
+
+      @if $rfs-two-dimensional {
+        @media (max-width: #{$mq-value}), (max-height: #{$mq-value}) {
+          @if $rfs-class == "enable" {
+            .enable-responsive-font-size &,
+            &.enable-responsive-font-size {
+              font-size: $rfs-fluid;
+            }
+          }
+          @else {
+            font-size: $rfs-fluid;
+          }
+
+          @if $rfs-safari-iframe-resize-bug-fix {
+            // stylelint-disable-next-line length-zero-no-unit
+            min-width: 0vw;
+          }
+        }
+      }
+      @else {
+        @media (max-width: #{$mq-value}) {
+          @if $rfs-class == "enable" {
+            .enable-responsive-font-size &,
+            &.enable-responsive-font-size {
+              font-size: $rfs-fluid;
+            }
+          }
+          @else {
+            font-size: $rfs-fluid;
+          }
+
+          @if $rfs-safari-iframe-resize-bug-fix {
+            // stylelint-disable-next-line length-zero-no-unit
+            min-width: 0vw;
+          }
+        }
+      }
+    }
+  }
+}
+
+// The font-size & responsive-font-size mixin uses RFS to rescale font sizes
+@mixin font-size($fs, $important: false) {
+  @include rfs($fs, $important);
+}
+
+@mixin responsive-font-size($fs, $important: false) {
+  @include rfs($fs, $important);
+}