development/examples/example3/build/assets/sass/_variables.scss

+/*===========================================================
+
+   Template Name: iDocs - One Page Documentation HTML Template
+   Author: Harnish Design
+   Template URL: http://demo.harnishdesign.net/html/idocs
+   Author URL: https://themeforest.net/user/harnishdesign
+   File Description : Main css file of the template
+	
+=================================================
+  Table of Contents
+=================================================
+
+	1. Basic
+	2. Helpers Classes
+	3. Layouts
+		3.1 Side Navigation
+		3.2 Docs Content
+		3.3 Section Divider
+	4. Header
+		4.1 Main Navigation
+	5 Elements
+		5.1 List Style
+		5.2 Changelog
+		5.3 Accordion & Toggle
+		5.4 Nav
+		5.5 Tabs
+		5.6 Popup Img
+		5.7 Featured Box
+	6 Footer
+		6.1 Social Icons
+		6.2 Back to Top
+	7 Extra
+
+=======================================================*/
+
+//-------------------- Base Colors --------------------//
+
+$primary-color: 			#0366d6;
+$primary-color-hover: 		darken($primary-color, 7%);
+$secondary-color: 			$secondary;
+
+$body-bg:					#dddddd;
+$text-color:				#4c4d4d;
+$title-color:     			#252b33;
\ No newline at end of file

development/examples/example3/build/assets/sass/bootstrap/_alert.scss

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

development/examples/example3/build/assets/sass/bootstrap/_badge.scss

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

development/examples/example3/build/assets/sass/bootstrap/_breadcrumb.scss

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

development/examples/example3/build/assets/sass/bootstrap/_button-group.scss

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

development/examples/example3/build/assets/sass/bootstrap/_buttons.scss

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

development/examples/example3/build/assets/sass/bootstrap/_card.scss

+//
+// Base styles
+//
+
+.card {
+  position: relative;
+  display: flex;
+  flex-direction: column;
+  min-width: 0; // See https://github.com/twbs/bootstrap/pull/22740#issuecomment-305868106
+  height: $card-height;
+  word-wrap: break-word;
+  background-color: $card-bg;
+  background-clip: border-box;
+  border: $card-border-width solid $card-border-color;
+  @include border-radius($card-border-radius);
+
+  > hr {
+    margin-right: 0;
+    margin-left: 0;
+  }
+
+  > .list-group {
+    border-top: inherit;
+    border-bottom: inherit;
+
+    &:first-child {
+      border-top-width: 0;
+      @include border-top-radius($card-inner-border-radius);
+    }
+
+    &:last-child  {
+      border-bottom-width: 0;
+      @include border-bottom-radius($card-inner-border-radius);
+    }
+  }
+
+  // Due to specificity of the above selector (`.card > .list-group`), we must
+  // use a child selector here to prevent double borders.
+  > .card-header + .list-group,
+  > .list-group + .card-footer {
+    border-top: 0;
+  }
+}
+
+.card-body {
+  // Enable `flex-grow: 1` for decks and groups so that card blocks take up
+  // as much space as possible, ensuring footers are aligned to the bottom.
+  flex: 1 1 auto;
+  // Workaround for the image size bug in IE
+  // See: https://github.com/twbs/bootstrap/pull/28855
+  min-height: 1px;
+  padding: $card-spacer-x;
+  color: $card-color;
+}
+
+.card-title {
+  margin-bottom: $card-spacer-y;
+}
+
+.card-subtitle {
+  margin-top: -$card-spacer-y / 2;
+  margin-bottom: 0;
+}
+
+.card-text:last-child {
+  margin-bottom: 0;
+}
+
+.card-link {
+  @include hover() {
+    text-decoration: none;
+  }
+
+  + .card-link {
+    margin-left: $card-spacer-x;
+  }
+}
+
+//
+// Optional textual caps
+//
+
+.card-header {
+  padding: $card-spacer-y $card-spacer-x;
+  margin-bottom: 0; // Removes the default margin-bottom of <hN>
+  color: $card-cap-color;
+  background-color: $card-cap-bg;
+  border-bottom: $card-border-width solid $card-border-color;
+
+  &:first-child {
+    @include border-radius($card-inner-border-radius $card-inner-border-radius 0 0);
+  }
+}
+
+.card-footer {
+  padding: $card-spacer-y $card-spacer-x;
+  color: $card-cap-color;
+  background-color: $card-cap-bg;
+  border-top: $card-border-width solid $card-border-color;
+
+  &:last-child {
+    @include border-radius(0 0 $card-inner-border-radius $card-inner-border-radius);
+  }
+}
+
+
+//
+// Header navs
+//
+
+.card-header-tabs {
+  margin-right: -$card-spacer-x / 2;
+  margin-bottom: -$card-spacer-y;
+  margin-left: -$card-spacer-x / 2;
+  border-bottom: 0;
+}
+
+.card-header-pills {
+  margin-right: -$card-spacer-x / 2;
+  margin-left: -$card-spacer-x / 2;
+}
+
+// Card image
+.card-img-overlay {
+  position: absolute;
+  top: 0;
+  right: 0;
+  bottom: 0;
+  left: 0;
+  padding: $card-img-overlay-padding;
+  @include border-radius($card-inner-border-radius);
+}
+
+.card-img,
+.card-img-top,
+.card-img-bottom {
+  flex-shrink: 0; // For IE: https://github.com/twbs/bootstrap/issues/29396
+  width: 100%; // Required because we use flexbox and this inherently applies align-self: stretch
+}
+
+.card-img,
+.card-img-top {
+  @include border-top-radius($card-inner-border-radius);
+}
+
+.card-img,
+.card-img-bottom {
+  @include border-bottom-radius($card-inner-border-radius);
+}
+
+
+// Card deck
+
+.card-deck {
+  .card {
+    margin-bottom: $card-deck-margin;
+  }
+
+  @include media-breakpoint-up(sm) {
+    display: flex;
+    flex-flow: row wrap;
+    margin-right: -$card-deck-margin;
+    margin-left: -$card-deck-margin;
+
+    .card {
+      // Flexbugs #4: https://github.com/philipwalton/flexbugs#flexbug-4
+      flex: 1 0 0%;
+      margin-right: $card-deck-margin;
+      margin-bottom: 0; // Override the default
+      margin-left: $card-deck-margin;
+    }
+  }
+}
+
+
+//
+// Card groups
+//
+
+.card-group {
+  // The child selector allows nested `.card` within `.card-group`
+  // to display properly.
+  > .card {
+    margin-bottom: $card-group-margin;
+  }
+
+  @include media-breakpoint-up(sm) {
+    display: flex;
+    flex-flow: row wrap;
+    // The child selector allows nested `.card` within `.card-group`
+    // to display properly.
+    > .card {
+      // Flexbugs #4: https://github.com/philipwalton/flexbugs#flexbug-4
+      flex: 1 0 0%;
+      margin-bottom: 0;
+
+      + .card {
+        margin-left: 0;
+        border-left: 0;
+      }
+
+      // Handle rounded corners
+      @if $enable-rounded {
+        &:not(:last-child) {
+          @include border-right-radius(0);
+
+          .card-img-top,
+          .card-header {
+            // stylelint-disable-next-line property-blacklist
+            border-top-right-radius: 0;
+          }
+          .card-img-bottom,
+          .card-footer {
+            // stylelint-disable-next-line property-blacklist
+            border-bottom-right-radius: 0;
+          }
+        }
+
+        &:not(:first-child) {
+          @include border-left-radius(0);
+
+          .card-img-top,
+          .card-header {
+            // stylelint-disable-next-line property-blacklist
+            border-top-left-radius: 0;
+          }
+          .card-img-bottom,
+          .card-footer {
+            // stylelint-disable-next-line property-blacklist
+            border-bottom-left-radius: 0;
+          }
+        }
+      }
+    }
+  }
+}
+
+
+//
+// Columns
+//
+
+.card-columns {
+  .card {
+    margin-bottom: $card-columns-margin;
+  }
+
+  @include media-breakpoint-up(sm) {
+    column-count: $card-columns-count;
+    column-gap: $card-columns-gap;
+    orphans: 1;
+    widows: 1;
+
+    .card {
+      display: inline-block; // Don't let them vertically span multiple columns
+      width: 100%; // Don't let their width change
+    }
+  }
+}
+
+
+//
+// Accordion
+//
+
+.accordion {
+  overflow-anchor: none;
+
+  > .card {
+    overflow: hidden;
+
+    &:not(:last-of-type) {
+      border-bottom: 0;
+      @include border-bottom-radius(0);
+    }
+
+    &:not(:first-of-type) {
+      @include border-top-radius(0);
+    }
+
+    > .card-header {
+      @include border-radius(0);
+      margin-bottom: -$card-border-width;
+    }
+  }
+}

development/examples/example3/build/assets/sass/bootstrap/_carousel.scss

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

development/examples/example3/build/assets/sass/bootstrap/_close.scss

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

development/examples/example3/build/assets/sass/bootstrap/_code.scss

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

development/examples/example3/build/assets/sass/bootstrap/_custom-forms.scss

+// Embedded icons from Open Iconic.
+// Released under MIT and copyright 2014 Waybury.
+// https://useiconic.com/open
+
+
+// Checkboxes and radios
+//
+// Base class takes care of all the key behavioral aspects.
+
+.custom-control {
+  position: relative;
+  z-index: 1;
+  display: block;
+  min-height: $font-size-base * $line-height-base;
+  padding-left: $custom-control-gutter + $custom-control-indicator-size;
+}
+
+.custom-control-inline {
+  display: inline-flex;
+  margin-right: $custom-control-spacer-x;
+}
+
+.custom-control-input {
+  position: absolute;
+  left: 0;
+  z-index: -1; // Put the input behind the label so it doesn't overlay text
+  width: $custom-control-indicator-size;
+  height: ($font-size-base * $line-height-base + $custom-control-indicator-size) / 2;
+  opacity: 0;
+
+  &:checked ~ .custom-control-label::before {
+    color: $custom-control-indicator-checked-color;
+    border-color: $custom-control-indicator-checked-border-color;
+    @include gradient-bg($custom-control-indicator-checked-bg);
+    @include box-shadow($custom-control-indicator-checked-box-shadow);
+  }
+
+  &:focus ~ .custom-control-label::before {
+    // the mixin is not used here to make sure there is feedback
+    @if $enable-shadows {
+      box-shadow: $input-box-shadow, $input-focus-box-shadow;
+    } @else {
+      box-shadow: $custom-control-indicator-focus-box-shadow;
+    }
+  }
+
+  &:focus:not(:checked) ~ .custom-control-label::before {
+    border-color: $custom-control-indicator-focus-border-color;
+  }
+
+  &:not(:disabled):active ~ .custom-control-label::before {
+    color: $custom-control-indicator-active-color;
+    background-color: $custom-control-indicator-active-bg;
+    border-color: $custom-control-indicator-active-border-color;
+    @include box-shadow($custom-control-indicator-active-box-shadow);
+  }
+
+  // Use [disabled] and :disabled to work around https://github.com/twbs/bootstrap/issues/28247
+  &[disabled],
+  &:disabled {
+    ~ .custom-control-label {
+      color: $custom-control-label-disabled-color;
+
+      &::before {
+        background-color: $custom-control-indicator-disabled-bg;
+      }
+    }
+  }
+}
+
+// Custom control indicators
+//
+// Build the custom controls out of pseudo-elements.
+
+.custom-control-label {
+  position: relative;
+  margin-bottom: 0;
+  color: $custom-control-label-color;
+  vertical-align: top;
+  cursor: $custom-control-cursor;
+
+  // Background-color and (when enabled) gradient
+  &::before {
+    position: absolute;
+    top: ($font-size-base * $line-height-base - $custom-control-indicator-size) / 2;
+    left: -($custom-control-gutter + $custom-control-indicator-size);
+    display: block;
+    width: $custom-control-indicator-size;
+    height: $custom-control-indicator-size;
+    pointer-events: none;
+    content: "";
+    background-color: $custom-control-indicator-bg;
+    border: $custom-control-indicator-border-color solid $custom-control-indicator-border-width;
+    @include box-shadow($custom-control-indicator-box-shadow);
+  }
+
+  // Foreground (icon)
+  &::after {
+    position: absolute;
+    top: ($font-size-base * $line-height-base - $custom-control-indicator-size) / 2;
+    left: -($custom-control-gutter + $custom-control-indicator-size);
+    display: block;
+    width: $custom-control-indicator-size;
+    height: $custom-control-indicator-size;
+    content: "";
+    background: no-repeat 50% / #{$custom-control-indicator-bg-size};
+  }
+}
+
+
+// Checkboxes
+//
+// Tweak just a few things for checkboxes.
+
+.custom-checkbox {
+  .custom-control-label::before {
+    @include border-radius($custom-checkbox-indicator-border-radius);
+  }
+
+  .custom-control-input:checked ~ .custom-control-label {
+    &::after {
+      background-image: escape-svg($custom-checkbox-indicator-icon-checked);
+    }
+  }
+
+  .custom-control-input:indeterminate ~ .custom-control-label {
+    &::before {
+      border-color: $custom-checkbox-indicator-indeterminate-border-color;
+      @include gradient-bg($custom-checkbox-indicator-indeterminate-bg);
+      @include box-shadow($custom-checkbox-indicator-indeterminate-box-shadow);
+    }
+    &::after {
+      background-image: escape-svg($custom-checkbox-indicator-icon-indeterminate);
+    }
+  }
+
+  .custom-control-input:disabled {
+    &:checked ~ .custom-control-label::before {
+      @include gradient-bg($custom-control-indicator-checked-disabled-bg);
+    }
+    &:indeterminate ~ .custom-control-label::before {
+      @include gradient-bg($custom-control-indicator-checked-disabled-bg);
+    }
+  }
+}
+
+// Radios
+//
+// Tweak just a few things for radios.
+
+.custom-radio {
+  .custom-control-label::before {
+    // stylelint-disable-next-line property-blacklist
+    border-radius: $custom-radio-indicator-border-radius;
+  }
+
+  .custom-control-input:checked ~ .custom-control-label {
+    &::after {
+      background-image: escape-svg($custom-radio-indicator-icon-checked);
+    }
+  }
+
+  .custom-control-input:disabled {
+    &:checked ~ .custom-control-label::before {
+      @include gradient-bg($custom-control-indicator-checked-disabled-bg);
+    }
+  }
+}
+
+
+// switches
+//
+// Tweak a few things for switches
+
+.custom-switch {
+  padding-left: $custom-switch-width + $custom-control-gutter;
+
+  .custom-control-label {
+    &::before {
+      left: -($custom-switch-width + $custom-control-gutter);
+      width: $custom-switch-width;
+      pointer-events: all;
+      // stylelint-disable-next-line property-blacklist
+      border-radius: $custom-switch-indicator-border-radius;
+    }
+
+    &::after {
+      top: add(($font-size-base * $line-height-base - $custom-control-indicator-size) / 2, $custom-control-indicator-border-width * 2);
+      left: add(-($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 - $custom-control-indicator-size);
+    }
+  }
+
+  .custom-control-input:disabled {
+    &:checked ~ .custom-control-label::before {
+      @include gradient-bg($custom-control-indicator-checked-disabled-bg);
+    }
+  }
+}
+
+
+// Select
+//
+// Replaces the browser default select with a custom one, mostly pulled from
+// https://primer.github.io/.
+//
+
+.custom-select {
+  display: inline-block;
+  width: 100%;
+  height: $custom-select-height;
+  padding: $custom-select-padding-y ($custom-select-padding-x + $custom-select-indicator-padding) $custom-select-padding-y $custom-select-padding-x;
+  font-family: $custom-select-font-family;
+  @include font-size($custom-select-font-size);
+  font-weight: $custom-select-font-weight;
+  line-height: $custom-select-line-height;
+  color: $custom-select-color;
+  vertical-align: middle;
+  background: $custom-select-bg $custom-select-background;
+  border: $custom-select-border-width solid $custom-select-border-color;
+  @include border-radius($custom-select-border-radius, 0);
+  @include box-shadow($custom-select-box-shadow);
+  appearance: none;
+
+  &:focus {
+    border-color: $custom-select-focus-border-color;
+    outline: 0;
+    @if $enable-shadows {
+      @include box-shadow($custom-select-box-shadow, $custom-select-focus-box-shadow);
+    } @else {
+      // Avoid using mixin so we can pass custom focus shadow properly
+      box-shadow: $custom-select-focus-box-shadow;
+    }
+
+    &::-ms-value {
+      // For visual consistency with other platforms/browsers,
+      // suppress the default white text on blue background highlight given to
+      // the selected option text when the (still closed) <select> receives focus
+      // in IE and (under certain conditions) Edge.
+      // See https://github.com/twbs/bootstrap/issues/19398.
+      color: $input-color;
+      background-color: $input-bg;
+    }
+  }
+
+  &[multiple],
+  &[size]:not([size="1"]) {
+    height: auto;
+    padding-right: $custom-select-padding-x;
+    background-image: none;
+  }
+
+  &:disabled {
+    color: $custom-select-disabled-color;
+    background-color: $custom-select-disabled-bg;
+  }
+
+  // Hides the default caret in IE11
+  &::-ms-expand {
+    display: none;
+  }
+
+  // Remove outline from select box in FF
+  &:-moz-focusring {
+    color: transparent;
+    text-shadow: 0 0 0 $custom-select-color;
+  }
+}
+
+.custom-select-sm {
+  height: $custom-select-height-sm;
+  padding-top: $custom-select-padding-y-sm;
+  padding-bottom: $custom-select-padding-y-sm;
+  padding-left: $custom-select-padding-x-sm;
+  @include font-size($custom-select-font-size-sm);
+}
+
+.custom-select-lg {
+  height: $custom-select-height-lg;
+  padding-top: $custom-select-padding-y-lg;
+  padding-bottom: $custom-select-padding-y-lg;
+  padding-left: $custom-select-padding-x-lg;
+  @include font-size($custom-select-font-size-lg);
+}
+
+
+// File
+//
+// Custom file input.
+
+.custom-file {
+  position: relative;
+  display: inline-block;
+  width: 100%;
+  height: $custom-file-height;
+  margin-bottom: 0;
+}
+
+.custom-file-input {
+  position: relative;
+  z-index: 2;
+  width: 100%;
+  height: $custom-file-height;
+  margin: 0;
+  opacity: 0;
+
+  &:focus ~ .custom-file-label {
+    border-color: $custom-file-focus-border-color;
+    box-shadow: $custom-file-focus-box-shadow;
+  }
+
+  // Use [disabled] and :disabled to work around https://github.com/twbs/bootstrap/issues/28247
+  &[disabled] ~ .custom-file-label,
+  &:disabled ~ .custom-file-label {
+    background-color: $custom-file-disabled-bg;
+  }
+
+  @each $lang, $value in $custom-file-text {
+    &:lang(#{$lang}) ~ .custom-file-label::after {
+      content: $value;
+    }
+  }
+
+  ~ .custom-file-label[data-browse]::after {
+    content: attr(data-browse);
+  }
+}
+
+.custom-file-label {
+  position: absolute;
+  top: 0;
+  right: 0;
+  left: 0;
+  z-index: 1;
+  height: $custom-file-height;
+  padding: $custom-file-padding-y $custom-file-padding-x;
+  font-family: $custom-file-font-family;
+  font-weight: $custom-file-font-weight;
+  line-height: $custom-file-line-height;
+  color: $custom-file-color;
+  background-color: $custom-file-bg;
+  border: $custom-file-border-width solid $custom-file-border-color;
+  @include border-radius($custom-file-border-radius);
+  @include box-shadow($custom-file-box-shadow);
+
+  &::after {
+    position: absolute;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    z-index: 3;
+    display: block;
+    height: $custom-file-height-inner;
+    padding: $custom-file-padding-y $custom-file-padding-x;
+    line-height: $custom-file-line-height;
+    color: $custom-file-button-color;
+    content: "Browse";
+    @include gradient-bg($custom-file-button-bg);
+    border-left: inherit;
+    @include border-radius(0 $custom-file-border-radius $custom-file-border-radius 0);
+  }
+}
+
+// Range
+//
+// Style range inputs the same across browsers. Vendor-specific rules for pseudo
+// elements cannot be mixed. As such, there are no shared styles for focus or
+// active states on prefixed selectors.
+
+.custom-range {
+  width: 100%;
+  height: add($custom-range-thumb-height, $custom-range-thumb-focus-box-shadow-width * 2);
+  padding: 0; // Need to reset padding
+  background-color: transparent;
+  appearance: none;
+
+  &:focus {
+    outline: none;
+
+    // Pseudo-elements must be split across multiple rulesets to have an effect.
+    // No box-shadow() mixin for focus accessibility.
+    &::-webkit-slider-thumb { box-shadow: $custom-range-thumb-focus-box-shadow; }
+    &::-moz-range-thumb     { box-shadow: $custom-range-thumb-focus-box-shadow; }
+    &::-ms-thumb            { box-shadow: $custom-range-thumb-focus-box-shadow; }
+  }
+
+  &::-moz-focus-outer {
+    border: 0;
+  }
+
+  &::-webkit-slider-thumb {
+    width: $custom-range-thumb-width;
+    height: $custom-range-thumb-height;
+    margin-top: ($custom-range-track-height - $custom-range-thumb-height) / 2; // Webkit specific
+    @include gradient-bg($custom-range-thumb-bg);
+    border: $custom-range-thumb-border;
+    @include border-radius($custom-range-thumb-border-radius);
+    @include box-shadow($custom-range-thumb-box-shadow);
+    @include transition($custom-forms-transition);
+    appearance: none;
+
+    &:active {
+      @include gradient-bg($custom-range-thumb-active-bg);
+    }
+  }
+
+  &::-webkit-slider-runnable-track {
+    width: $custom-range-track-width;
+    height: $custom-range-track-height;
+    color: transparent; // Why?
+    cursor: $custom-range-track-cursor;
+    background-color: $custom-range-track-bg;
+    border-color: transparent;
+    @include border-radius($custom-range-track-border-radius);
+    @include box-shadow($custom-range-track-box-shadow);
+  }
+
+  &::-moz-range-thumb {
+    width: $custom-range-thumb-width;
+    height: $custom-range-thumb-height;
+    @include gradient-bg($custom-range-thumb-bg);
+    border: $custom-range-thumb-border;
+    @include border-radius($custom-range-thumb-border-radius);
+    @include box-shadow($custom-range-thumb-box-shadow);
+    @include transition($custom-forms-transition);
+    appearance: none;
+
+    &:active {
+      @include gradient-bg($custom-range-thumb-active-bg);
+    }
+  }
+
+  &::-moz-range-track {
+    width: $custom-range-track-width;
+    height: $custom-range-track-height;
+    color: transparent;
+    cursor: $custom-range-track-cursor;
+    background-color: $custom-range-track-bg;
+    border-color: transparent; // Firefox specific?
+    @include border-radius($custom-range-track-border-radius);
+    @include box-shadow($custom-range-track-box-shadow);
+  }
+
+  &::-ms-thumb {
+    width: $custom-range-thumb-width;
+    height: $custom-range-thumb-height;
+    margin-top: 0; // Edge specific
+    margin-right: $custom-range-thumb-focus-box-shadow-width; // Workaround that overflowed box-shadow is hidden.
+    margin-left: $custom-range-thumb-focus-box-shadow-width;  // Workaround that overflowed box-shadow is hidden.
+    @include gradient-bg($custom-range-thumb-bg);
+    border: $custom-range-thumb-border;
+    @include border-radius($custom-range-thumb-border-radius);
+    @include box-shadow($custom-range-thumb-box-shadow);
+    @include transition($custom-forms-transition);
+    appearance: none;
+
+    &:active {
+      @include gradient-bg($custom-range-thumb-active-bg);
+    }
+  }
+
+  &::-ms-track {
+    width: $custom-range-track-width;
+    height: $custom-range-track-height;
+    color: transparent;
+    cursor: $custom-range-track-cursor;
+    background-color: transparent;
+    border-color: transparent;
+    border-width: $custom-range-thumb-height / 2;
+    @include box-shadow($custom-range-track-box-shadow);
+  }
+
+  &::-ms-fill-lower {
+    background-color: $custom-range-track-bg;
+    @include border-radius($custom-range-track-border-radius);
+  }
+
+  &::-ms-fill-upper {
+    margin-right: 15px; // arbitrary?
+    background-color: $custom-range-track-bg;
+    @include border-radius($custom-range-track-border-radius);
+  }
+
+  &:disabled {
+    &::-webkit-slider-thumb {
+      background-color: $custom-range-thumb-disabled-bg;
+    }
+
+    &::-webkit-slider-runnable-track {
+      cursor: default;
+    }
+
+    &::-moz-range-thumb {
+      background-color: $custom-range-thumb-disabled-bg;
+    }
+
+    &::-moz-range-track {
+      cursor: default;
+    }
+
+    &::-ms-thumb {
+      background-color: $custom-range-thumb-disabled-bg;
+    }
+  }
+}
+
+.custom-control-label::before,
+.custom-file-label,
+.custom-select {
+  @include transition($custom-forms-transition);
+}

development/examples/example3/build/assets/sass/bootstrap/_dropdown.scss

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

development/examples/example3/build/assets/sass/bootstrap/_forms.scss

+// stylelint-disable selector-no-qualifying-type
+
+//
+// Textual form controls
+//
+
+.form-control {
+  display: block;
+  width: 100%;
+  height: $input-height;
+  padding: $input-padding-y $input-padding-x;
+  font-family: $input-font-family;
+  @include font-size($input-font-size);
+  font-weight: $input-font-weight;
+  line-height: $input-line-height;
+  color: $input-color;
+  background-color: $input-bg;
+  background-clip: padding-box;
+  border: $input-border-width solid $input-border-color;
+
+  // Note: This has no effect on <select>s in some browsers, due to the limited stylability of `<select>`s in CSS.
+  @include border-radius($input-border-radius, 0);
+
+  @include box-shadow($input-box-shadow);
+  @include transition($input-transition);
+
+  // Unstyle the caret on `<select>`s in IE10+.
+  &::-ms-expand {
+    background-color: transparent;
+    border: 0;
+  }
+
+  // Remove select outline from select box in FF
+  &:-moz-focusring {
+    color: transparent;
+    text-shadow: 0 0 0 $input-color;
+  }
+
+  // Customize the `:focus` state to imitate native WebKit styles.
+  @include form-control-focus($ignore-warning: true);
+
+  // Placeholder
+  &::placeholder {
+    color: $input-placeholder-color;
+    // Override Firefox's unusual default opacity; see https://github.com/twbs/bootstrap/pull/11526.
+    opacity: 1;
+  }
+
+  // Disabled and read-only inputs
+  //
+  // HTML5 says that controls under a fieldset > legend:first-child won't be
+  // disabled if the fieldset is disabled. Due to implementation difficulty, we
+  // don't honor that edge case; we style them as disabled anyway.
+  &:disabled,
+  &[readonly] {
+    background-color: $input-disabled-bg;
+    // iOS fix for unreadable disabled content; see https://github.com/twbs/bootstrap/issues/11655.
+    opacity: 1;
+  }
+}
+
+input[type="date"],
+input[type="time"],
+input[type="datetime-local"],
+input[type="month"] {
+  &.form-control {
+    appearance: none; // Fix appearance for date inputs in Safari
+  }
+}
+
+select.form-control {
+  &:focus::-ms-value {
+    // Suppress the nested default white text on blue background highlight given to
+    // the selected option text when the (still closed) <select> receives focus
+    // in IE and (under certain conditions) Edge, as it looks bad and cannot be made to
+    // match the appearance of the native widget.
+    // See https://github.com/twbs/bootstrap/issues/19398.
+    color: $input-color;
+    background-color: $input-bg;
+  }
+}
+
+// Make file inputs better match text inputs by forcing them to new lines.
+.form-control-file,
+.form-control-range {
+  display: block;
+  width: 100%;
+}
+
+
+//
+// Labels
+//
+
+// For use with horizontal and inline forms, when you need the label (or legend)
+// text to align with the form controls.
+.col-form-label {
+  padding-top: add($input-padding-y, $input-border-width);
+  padding-bottom: add($input-padding-y, $input-border-width);
+  margin-bottom: 0; // Override the `<label>/<legend>` default
+  @include font-size(inherit); // Override the `<legend>` default
+  line-height: $input-line-height;
+}
+
+.col-form-label-lg {
+  padding-top: add($input-padding-y-lg, $input-border-width);
+  padding-bottom: add($input-padding-y-lg, $input-border-width);
+  @include font-size($input-font-size-lg);
+  line-height: $input-line-height-lg;
+}
+
+.col-form-label-sm {
+  padding-top: add($input-padding-y-sm, $input-border-width);
+  padding-bottom: add($input-padding-y-sm, $input-border-width);
+  @include font-size($input-font-size-sm);
+  line-height: $input-line-height-sm;
+}
+
+
+// Readonly controls as plain text
+//
+// Apply class to a readonly input to make it appear like regular plain
+// text (without any border, background color, focus indicator)
+
+.form-control-plaintext {
+  display: block;
+  width: 100%;
+  padding: $input-padding-y 0;
+  margin-bottom: 0; // match inputs if this class comes on inputs with default margins
+  @include font-size($input-font-size);
+  line-height: $input-line-height;
+  color: $input-plaintext-color;
+  background-color: transparent;
+  border: solid transparent;
+  border-width: $input-border-width 0;
+
+  &.form-control-sm,
+  &.form-control-lg {
+    padding-right: 0;
+    padding-left: 0;
+  }
+}
+
+
+// Form control sizing
+//
+// Build on `.form-control` with modifier classes to decrease or increase the
+// height and font-size of form controls.
+//
+// Repeated in `_input_group.scss` to avoid Sass extend issues.
+
+.form-control-sm {
+  height: $input-height-sm;
+  padding: $input-padding-y-sm $input-padding-x-sm;
+  @include font-size($input-font-size-sm);
+  line-height: $input-line-height-sm;
+  @include border-radius($input-border-radius-sm);
+}
+
+.form-control-lg {
+  height: $input-height-lg;
+  padding: $input-padding-y-lg $input-padding-x-lg;
+  @include font-size($input-font-size-lg);
+  line-height: $input-line-height-lg;
+  @include border-radius($input-border-radius-lg);
+}
+
+// stylelint-disable-next-line no-duplicate-selectors
+select.form-control {
+  &[size],
+  &[multiple] {
+    height: auto;
+  }
+}
+
+textarea.form-control {
+  height: auto;
+}
+
+// Form groups
+//
+// Designed to help with the organization and spacing of vertical forms. For
+// horizontal forms, use the predefined grid classes.
+
+.form-group {
+  margin-bottom: $form-group-margin-bottom;
+}
+
+.form-text {
+  display: block;
+  margin-top: $form-text-margin-top;
+}
+
+
+// Form grid
+//
+// Special replacement for our grid system's `.row` for tighter form layouts.
+
+.form-row {
+  display: flex;
+  flex-wrap: wrap;
+  margin-right: -$form-grid-gutter-width / 2;
+  margin-left: -$form-grid-gutter-width / 2;
+
+  > .col,
+  > [class*="col-"] {
+    padding-right: $form-grid-gutter-width / 2;
+    padding-left: $form-grid-gutter-width / 2;
+  }
+}
+
+
+// Checkboxes and radios
+//
+// Indent the labels to position radios/checkboxes as hanging controls.
+
+.form-check {
+  position: relative;
+  display: block;
+  padding-left: $form-check-input-gutter;
+}
+
+.form-check-input {
+  position: absolute;
+  margin-top: $form-check-input-margin-y;
+  margin-left: -$form-check-input-gutter;
+
+  // Use [disabled] and :disabled for workaround https://github.com/twbs/bootstrap/issues/28247
+  &[disabled] ~ .form-check-label,
+  &:disabled ~ .form-check-label {
+    color: $text-muted;
+  }
+}
+
+.form-check-label {
+  margin-bottom: 0; // Override default `<label>` bottom margin
+}
+
+.form-check-inline {
+  display: inline-flex;
+  align-items: center;
+  padding-left: 0; // Override base .form-check
+  margin-right: $form-check-inline-margin-x;
+
+  // Undo .form-check-input defaults and add some `margin-right`.
+  .form-check-input {
+    position: static;
+    margin-top: 0;
+    margin-right: $form-check-inline-input-margin-x;
+    margin-left: 0;
+  }
+}
+
+
+// Form validation
+//
+// Provide feedback to users when form field values are valid or invalid. Works
+// primarily for client-side validation via scoped `:invalid` and `:valid`
+// pseudo-classes but also includes `.is-invalid` and `.is-valid` classes for
+// server side validation.
+
+@each $state, $data in $form-validation-states {
+  @include form-validation-state($state, map-get($data, color), map-get($data, icon));
+}
+
+// Inline forms
+//
+// Make forms appear inline(-block) by adding the `.form-inline` class. Inline
+// forms begin stacked on extra small (mobile) devices and then go inline when
+// viewports reach <768px.
+//
+// Requires wrapping inputs and labels with `.form-group` for proper display of
+// default HTML form controls and our custom form controls (e.g., input groups).
+
+.form-inline {
+  display: flex;
+  flex-flow: row wrap;
+  align-items: center; // Prevent shorter elements from growing to same height as others (e.g., small buttons growing to normal sized button height)
+
+  // Because we use flex, the initial sizing of checkboxes is collapsed and
+  // doesn't occupy the full-width (which is what we want for xs grid tier),
+  // so we force that here.
+  .form-check {
+    width: 100%;
+  }
+
+  // Kick in the inline
+  @include media-breakpoint-up(sm) {
+    label {
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      margin-bottom: 0;
+    }
+
+    // Inline-block all the things for "inline"
+    .form-group {
+      display: flex;
+      flex: 0 0 auto;
+      flex-flow: row wrap;
+      align-items: center;
+      margin-bottom: 0;
+    }
+
+    // Allow folks to *not* use `.form-group`
+    .form-control {
+      display: inline-block;
+      width: auto; // Prevent labels from stacking above inputs in `.form-group`
+      vertical-align: middle;
+    }
+
+    // Make static controls behave like regular ones
+    .form-control-plaintext {
+      display: inline-block;
+    }
+
+    .input-group,
+    .custom-select {
+      width: auto;
+    }
+
+    // Remove default margin on radios/checkboxes that were used for stacking, and
+    // then undo the floating of radios and checkboxes to match.
+    .form-check {
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      width: auto;
+      padding-left: 0;
+    }
+    .form-check-input {
+      position: relative;
+      flex-shrink: 0;
+      margin-top: 0;
+      margin-right: $form-check-input-margin-x;
+      margin-left: 0;
+    }
+
+    .custom-control {
+      align-items: center;
+      justify-content: center;
+    }
+    .custom-control-label {
+      margin-bottom: 0;
+    }
+  }
+}

development/examples/example3/build/assets/sass/bootstrap/_functions.scss

+// Bootstrap functions
+//
+// Utility mixins and functions for evaluating source code across our variables, maps, and mixins.
+
+// Ascending
+// Used to evaluate Sass maps like our grid breakpoints.
+@mixin _assert-ascending($map, $map-name) {
+  $prev-key: null;
+  $prev-num: null;
+  @each $key, $num in $map {
+    @if $prev-num == null or unit($num) == "%" or unit($prev-num) == "%" {
+      // Do nothing
+    } @else if not comparable($prev-num, $num) {
+      @warn "Potentially invalid value for #{$map-name}: This map must be in ascending order, but key '#{$key}' has value #{$num} whose unit makes it incomparable to #{$prev-num}, the value of the previous key '#{$prev-key}' !";
+    } @else if $prev-num >= $num {
+      @warn "Invalid value for #{$map-name}: This map must be in ascending order, but key '#{$key}' has value #{$num} which isn't greater than #{$prev-num}, the value of the previous key '#{$prev-key}' !";
+    }
+    $prev-key: $key;
+    $prev-num: $num;
+  }
+}
+
+// Starts at zero
+// Used to ensure the min-width of the lowest breakpoint starts at 0.
+@mixin _assert-starts-at-zero($map, $map-name: "$grid-breakpoints") {
+  @if length($map) > 0 {
+    $values: map-values($map);
+    $first-value: nth($values, 1);
+    @if $first-value != 0 {
+      @warn "First breakpoint in #{$map-name} must start at 0, but starts at #{$first-value}.";
+    }
+  }
+}
+
+// Replace `$search` with `$replace` in `$string`
+// Used on our SVG icon backgrounds for custom forms.
+//
+// @author Hugo Giraudel
+// @param {String} $string - Initial string
+// @param {String} $search - Substring to replace
+// @param {String} $replace ('') - New value
+// @return {String} - Updated string
+@function str-replace($string, $search, $replace: "") {
+  $index: str-index($string, $search);
+
+  @if $index {
+    @return str-slice($string, 1, $index - 1) + $replace + str-replace(str-slice($string, $index + str-length($search)), $search, $replace);
+  }
+
+  @return $string;
+}
+
+// See https://codepen.io/kevinweber/pen/dXWoRw
+@function escape-svg($string) {
+  @if str-index($string, "data:image/svg+xml") {
+    @each $char, $encoded in $escaped-characters {
+      // Do not escape the url brackets
+      @if str-index($string, "url(") == 1 {
+        $string: url("#{str-replace(str-slice($string, 6, -3), $char, $encoded)}");
+      } @else {
+        $string: str-replace($string, $char, $encoded);
+      }
+    }
+  }
+
+  @return $string;
+}
+
+// Color contrast
+@function color-yiq($color, $dark: $yiq-text-dark, $light: $yiq-text-light) {
+  $r: red($color);
+  $g: green($color);
+  $b: blue($color);
+
+  $yiq: (($r * 299) + ($g * 587) + ($b * 114)) / 1000;
+
+  @if ($yiq >= $yiq-contrasted-threshold) {
+    @return $dark;
+  } @else {
+    @return $light;
+  }
+}
+
+// Retrieve color Sass maps
+@function color($key: "blue") {
+  @return map-get($colors, $key);
+}
+
+@function theme-color($key: "primary") {
+  @return map-get($theme-colors, $key);
+}
+
+@function gray($key: "100") {
+  @return map-get($grays, $key);
+}
+
+// Request a theme color level
+@function theme-color-level($color-name: "primary", $level: 0) {
+  $color: theme-color($color-name);
+  $color-base: if($level > 0, $black, $white);
+  $level: abs($level);
+
+  @return mix($color-base, $color, $level * $theme-color-interval);
+}
+
+// Return valid calc
+@function add($value1, $value2, $return-calc: true) {
+  @if $value1 == null {
+    @return $value2;
+  }
+
+  @if $value2 == null {
+    @return $value1;
+  }
+
+  @if type-of($value1) == number and type-of($value2) == number and comparable($value1, $value2) {
+    @return $value1 + $value2;
+  }
+
+  @return if($return-calc == true, calc(#{$value1} + #{$value2}), $value1 + unquote(" + ") + $value2);
+}
+
+@function subtract($value1, $value2, $return-calc: true) {
+  @if $value1 == null and $value2 == null {
+    @return null;
+  }
+
+  @if $value1 == null {
+    @return -$value2;
+  }
+
+  @if $value2 == null {
+    @return $value1;
+  }
+
+  @if type-of($value1) == number and type-of($value2) == number and comparable($value1, $value2) {
+    @return $value1 - $value2;
+  }
+
+  @return if($return-calc == true, calc(#{$value1} - #{$value2}), $value1 + unquote(" - ") + $value2);
+}

development/examples/example3/build/assets/sass/bootstrap/_grid.scss

+// Container widths
+//
+// Set the container width, and override it for fixed navbars in media queries.
+
+@if $enable-grid-classes {
+  // Single container class with breakpoint max-widths
+  .container,
+  // 100% wide container at all breakpoints
+  .container-fluid {
+    @include make-container();
+  }
+
+  // Responsive containers that are 100% wide until a breakpoint
+  @each $breakpoint, $container-max-width in $container-max-widths {
+    .container-#{$breakpoint} {
+      @extend .container-fluid;
+    }
+
+    @include media-breakpoint-up($breakpoint, $grid-breakpoints) {
+      %responsive-container-#{$breakpoint} {
+        max-width: $container-max-width;
+      }
+
+      // Extend each breakpoint which is smaller or equal to the current breakpoint
+      $extend-breakpoint: true;
+
+      @each $name, $width in $grid-breakpoints {
+        @if ($extend-breakpoint) {
+          .container#{breakpoint-infix($name, $grid-breakpoints)} {
+            @extend %responsive-container-#{$breakpoint};
+          }
+
+          // Once the current breakpoint is reached, stop extending
+          @if ($breakpoint == $name) {
+            $extend-breakpoint: false;
+          }
+        }
+      }
+    }
+  }
+}
+
+
+// Row
+//
+// Rows contain your columns.
+
+@if $enable-grid-classes {
+  .row {
+    @include make-row();
+  }
+
+  // Remove the negative margin from default .row, then the horizontal padding
+  // from all immediate children columns (to prevent runaway style inheritance).
+  .no-gutters {
+    margin-right: 0;
+    margin-left: 0;
+
+    > .col,
+    > [class*="col-"] {
+      padding-right: 0;
+      padding-left: 0;
+    }
+  }
+}
+
+// Columns
+//
+// Common styles for small and large grid columns
+
+@if $enable-grid-classes {
+  @include make-grid-columns();
+}

development/examples/example3/build/assets/sass/bootstrap/_images.scss

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

development/examples/example3/build/assets/sass/bootstrap/_input-group.scss

+// stylelint-disable selector-no-qualifying-type
+
+//
+// Base styles
+//
+
+.input-group {
+  position: relative;
+  display: flex;
+  flex-wrap: wrap; // For form validation feedback
+  align-items: stretch;
+  width: 100%;
+
+  > .form-control,
+  > .form-control-plaintext,
+  > .custom-select,
+  > .custom-file {
+    position: relative; // For focus state's z-index
+    flex: 1 1 auto;
+    width: 1%;
+    min-width: 0; // https://stackoverflow.com/questions/36247140/why-dont-flex-items-shrink-past-content-size
+    margin-bottom: 0;
+
+    + .form-control,
+    + .custom-select,
+    + .custom-file {
+      margin-left: -$input-border-width;
+    }
+  }
+
+  // Bring the "active" form control to the top of surrounding elements
+  > .form-control:focus,
+  > .custom-select:focus,
+  > .custom-file .custom-file-input:focus ~ .custom-file-label {
+    z-index: 3;
+  }
+
+  // Bring the custom file input above the label
+  > .custom-file .custom-file-input:focus {
+    z-index: 4;
+  }
+
+  > .form-control,
+  > .custom-select {
+    &:not(:last-child) { @include border-right-radius(0); }
+    &:not(:first-child) { @include border-left-radius(0); }
+  }
+
+  // Custom file inputs have more complex markup, thus requiring different
+  // border-radius overrides.
+  > .custom-file {
+    display: flex;
+    align-items: center;
+
+    &:not(:last-child) .custom-file-label,
+    &:not(:last-child) .custom-file-label::after { @include border-right-radius(0); }
+    &:not(:first-child) .custom-file-label { @include border-left-radius(0); }
+  }
+}
+
+
+// Prepend and append
+//
+// While it requires one extra layer of HTML for each, dedicated prepend and
+// append elements allow us to 1) be less clever, 2) simplify our selectors, and
+// 3) support HTML5 form validation.
+
+.input-group-prepend,
+.input-group-append {
+  display: flex;
+
+  // Ensure buttons are always above inputs for more visually pleasing borders.
+  // This isn't needed for `.input-group-text` since it shares the same border-color
+  // as our inputs.
+  .btn {
+    position: relative;
+    z-index: 2;
+
+    &:focus {
+      z-index: 3;
+    }
+  }
+
+  .btn + .btn,
+  .btn + .input-group-text,
+  .input-group-text + .input-group-text,
+  .input-group-text + .btn {
+    margin-left: -$input-border-width;
+  }
+}
+
+.input-group-prepend { margin-right: -$input-border-width; }
+.input-group-append { margin-left: -$input-border-width; }
+
+
+// Textual addons
+//
+// Serves as a catch-all element for any text or radio/checkbox input you wish
+// to prepend or append to an input.
+
+.input-group-text {
+  display: flex;
+  align-items: center;
+  padding: $input-padding-y $input-padding-x;
+  margin-bottom: 0; // Allow use of <label> elements by overriding our default margin-bottom
+  @include font-size($input-font-size); // Match inputs
+  font-weight: $font-weight-normal;
+  line-height: $input-line-height;
+  color: $input-group-addon-color;
+  text-align: center;
+  white-space: nowrap;
+  background-color: $input-group-addon-bg;
+  border: $input-border-width solid $input-group-addon-border-color;
+  @include border-radius($input-border-radius);
+
+  // Nuke default margins from checkboxes and radios to vertically center within.
+  input[type="radio"],
+  input[type="checkbox"] {
+    margin-top: 0;
+  }
+}
+
+
+// Sizing
+//
+// Remix the default form control sizing classes into new ones for easier
+// manipulation.
+
+.input-group-lg > .form-control:not(textarea),
+.input-group-lg > .custom-select {
+  height: $input-height-lg;
+}
+
+.input-group-lg > .form-control,
+.input-group-lg > .custom-select,
+.input-group-lg > .input-group-prepend > .input-group-text,
+.input-group-lg > .input-group-append > .input-group-text,
+.input-group-lg > .input-group-prepend > .btn,
+.input-group-lg > .input-group-append > .btn {
+  padding: $input-padding-y-lg $input-padding-x-lg;
+  @include font-size($input-font-size-lg);
+  line-height: $input-line-height-lg;
+  @include border-radius($input-border-radius-lg);
+}
+
+.input-group-sm > .form-control:not(textarea),
+.input-group-sm > .custom-select {
+  height: $input-height-sm;
+}
+
+.input-group-sm > .form-control,
+.input-group-sm > .custom-select,
+.input-group-sm > .input-group-prepend > .input-group-text,
+.input-group-sm > .input-group-append > .input-group-text,
+.input-group-sm > .input-group-prepend > .btn,
+.input-group-sm > .input-group-append > .btn {
+  padding: $input-padding-y-sm $input-padding-x-sm;
+  @include font-size($input-font-size-sm);
+  line-height: $input-line-height-sm;
+  @include border-radius($input-border-radius-sm);
+}
+
+.input-group-lg > .custom-select,
+.input-group-sm > .custom-select {
+  padding-right: $custom-select-padding-x + $custom-select-indicator-padding;
+}
+
+
+// Prepend and append rounded corners
+//
+// These rulesets must come after the sizing ones to properly override sm and lg
+// border-radius values when extending. They're more specific than we'd like
+// with the `.input-group >` part, but without it, we cannot override the sizing.
+
+
+.input-group > .input-group-prepend > .btn,
+.input-group > .input-group-prepend > .input-group-text,
+.input-group > .input-group-append:not(:last-child) > .btn,
+.input-group > .input-group-append:not(:last-child) > .input-group-text,
+.input-group > .input-group-append:last-child > .btn:not(:last-child):not(.dropdown-toggle),
+.input-group > .input-group-append:last-child > .input-group-text:not(:last-child) {
+  @include border-right-radius(0);
+}
+
+.input-group > .input-group-append > .btn,
+.input-group > .input-group-append > .input-group-text,
+.input-group > .input-group-prepend:not(:first-child) > .btn,
+.input-group > .input-group-prepend:not(:first-child) > .input-group-text,
+.input-group > .input-group-prepend:first-child > .btn:not(:first-child),
+.input-group > .input-group-prepend:first-child > .input-group-text:not(:first-child) {
+  @include border-left-radius(0);
+}

development/examples/example3/build/assets/sass/bootstrap/_jumbotron.scss

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

development/examples/example3/build/assets/sass/bootstrap/_list-group.scss

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

development/examples/example3/build/assets/sass/bootstrap/_media.scss

+.media {
+  display: flex;
+  align-items: flex-start;
+}
+
+.media-body {
+  flex: 1;
+}