Update to v5.0.0v5.0.0

1. Updater: Add `util/backdrop.js` to the list of inlined srcs.
2. `bundle exec rake 'update[v5.0.0]'
3. Update version numbers.
4. Bump minimum Popper version from 2.9.1 to 2.9.2

13 files changed, 61 insertions, 58 deletions

diff --git a/assets/stylesheets/bootstrap/_accordion.scss b/assets/stylesheets/bootstrap/_accordion.scss
index ae1ca0f..fc62ceb 100644
--- a/assets/stylesheets/bootstrap/_accordion.scss
+++ b/assets/stylesheets/bootstrap/_accordion.scss
@@ -58,7 +58,6 @@
 }
 
 .accordion-item {
-  margin-bottom: -$accordion-border-width;
   background-color: $accordion-bg;
   border: $accordion-border-width solid $accordion-border-color;
 
@@ -70,9 +69,12 @@
     }
   }
 
+  &:not(:first-of-type) {
+    border-top: 0;
+  }
+
   // Only set a border-radius on the last item if the accordion is collapsed
   &:last-of-type {
-    margin-bottom: 0;
     @include border-bottom-radius($accordion-border-radius);
 
     .accordion-button {
diff --git a/assets/stylesheets/bootstrap/_dropdown.scss b/assets/stylesheets/bootstrap/_dropdown.scss
index 209843f..06e70f7 100644
--- a/assets/stylesheets/bootstrap/_dropdown.scss
+++ b/assets/stylesheets/bootstrap/_dropdown.scss
@@ -16,7 +16,6 @@
 // The dropdown menu
 .dropdown-menu {
   position: absolute;
-  top: 100%;
   z-index: $zindex-dropdown;
   display: none; // none by default, but block on "open" of the menu
   min-width: $dropdown-min-width;
@@ -33,6 +32,7 @@
   @include box-shadow($dropdown-box-shadow);
 
   &[data-bs-popper] {
+    top: 100%;
     left: 0;
     margin-top: $dropdown-spacer;
   }
@@ -83,15 +83,12 @@
 }
 
 .dropend {
-  .dropdown-menu {
+  .dropdown-menu[data-bs-popper] {
     top: 0;
     right: auto;
     left: 100%;
-
-    &[data-bs-popper] {
-      margin-top: 0;
-      margin-left: $dropdown-spacer;
-    }
+    margin-top: 0;
+    margin-left: $dropdown-spacer;
   }
 
   .dropdown-toggle {
@@ -103,15 +100,12 @@
 }
 
 .dropstart {
-  .dropdown-menu {
+  .dropdown-menu[data-bs-popper] {
     top: 0;
     right: 100%;
     left: auto;
-
-    &[data-bs-popper] {
-      margin-top: 0;
-      margin-right: $dropdown-spacer;
-    }
+    margin-top: 0;
+    margin-right: $dropdown-spacer;
   }
 
   .dropdown-toggle {
diff --git a/assets/stylesheets/bootstrap/_list-group.scss b/assets/stylesheets/bootstrap/_list-group.scss
index 2193168..7daa9f1 100644
--- a/assets/stylesheets/bootstrap/_list-group.scss
+++ b/assets/stylesheets/bootstrap/_list-group.scss
@@ -166,7 +166,7 @@
   $list-group-background: shift-color($value, $list-group-item-bg-scale);
   $list-group-color: shift-color($value, $list-group-item-color-scale);
   @if (contrast-ratio($list-group-background, $list-group-color) < $min-contrast-ratio) {
-    $list-group-color: mix($value, color-contrast($list-group-background), abs($alert-color-scale));
+    $list-group-color: mix($value, color-contrast($list-group-background), abs($list-group-item-color-scale));
   }
 
   @include list-group-item-variant($state, $list-group-background, $list-group-color);
diff --git a/assets/stylesheets/bootstrap/_mixins.scss b/assets/stylesheets/bootstrap/_mixins.scss
index 7b06cd8..eec0857 100644
--- a/assets/stylesheets/bootstrap/_mixins.scss
+++ b/assets/stylesheets/bootstrap/_mixins.scss
@@ -10,6 +10,7 @@
 
 // Helpers
 @import "mixins/breakpoints";
+@import "mixins/color-scheme";
 @import "mixins/image";
 @import "mixins/resize";
 @import "mixins/visually-hidden";
diff --git a/assets/stylesheets/bootstrap/_modal.scss b/assets/stylesheets/bootstrap/_modal.scss
index 6dd4dd3..5138986 100644
--- a/assets/stylesheets/bootstrap/_modal.scss
+++ b/assets/stylesheets/bootstrap/_modal.scss
@@ -159,15 +159,6 @@
   }
 }
 
-// Measure scrollbar width for padding body during modal show/hide
-.modal-scrollbar-measure {
-  position: absolute;
-  top: -9999px;
-  width: 50px;
-  height: 50px;
-  overflow: scroll;
-}
-
 // Scale up the modal
 @include media-breakpoint-up(sm) {
   // Automatically set modal's width for larger viewports
diff --git a/assets/stylesheets/bootstrap/_offcanvas.scss b/assets/stylesheets/bootstrap/_offcanvas.scss
index 1eeb989..f1d9945 100644
--- a/assets/stylesheets/bootstrap/_offcanvas.scss
+++ b/assets/stylesheets/bootstrap/_offcanvas.scss
@@ -16,6 +16,7 @@
 
 .offcanvas-header {
   display: flex;
+  align-items: center;
   justify-content: space-between;
   padding: $offcanvas-padding-y $offcanvas-padding-x;
 
@@ -52,6 +53,16 @@
   transform: translateX(100%);
 }
 
+.offcanvas-top {
+  top: 0;
+  right: 0;
+  left: 0;
+  height: $offcanvas-vertical-height;
+  max-height: 100%;
+  border-bottom: $offcanvas-border-width solid $offcanvas-border-color;
+  transform: translateY(-100%);
+}
+
 .offcanvas-bottom {
   right: 0;
   left: 0;
@@ -64,14 +75,3 @@
 .offcanvas.show {
   transform: none;
 }
-
-.offcanvas-backdrop::before {
-  position: fixed;
-  top: 0;
-  left: 0;
-  z-index: $zindex-offcanvas - 1;
-  width: 100vw;
-  height: 100vh;
-  content: "";
-  background-color: $offcanvas-body-backdrop-color;
-}
diff --git a/assets/stylesheets/bootstrap/_spinners.scss b/assets/stylesheets/bootstrap/_spinners.scss
index 8e19bae..a4a2c77 100644
--- a/assets/stylesheets/bootstrap/_spinners.scss
+++ b/assets/stylesheets/bootstrap/_spinners.scss
@@ -12,7 +12,7 @@
   display: inline-block;
   width: $spinner-width;
   height: $spinner-height;
-  vertical-align: text-bottom;
+  vertical-align: $spinner-vertical-align;
   border: $spinner-border-width solid currentColor;
   border-right-color: transparent;
   // stylelint-disable-next-line property-disallowed-list
@@ -46,7 +46,7 @@
   display: inline-block;
   width: $spinner-width;
   height: $spinner-height;
-  vertical-align: text-bottom;
+  vertical-align: $spinner-vertical-align;
   background-color: currentColor;
   // stylelint-disable-next-line property-disallowed-list
   border-radius: 50%;
diff --git a/assets/stylesheets/bootstrap/_variables.scss b/assets/stylesheets/bootstrap/_variables.scss
index 7558224..1e17606 100644
--- a/assets/stylesheets/bootstrap/_variables.scss
+++ b/assets/stylesheets/bootstrap/_variables.scss
@@ -738,7 +738,7 @@ $form-check-transition:                   null !default;
 $form-check-input-active-filter:          brightness(90%) !default;
 
 $form-check-input-bg:                     $input-bg !default;
-$form-check-input-border:                 1px solid rgba(0, 0, 0, .25) !default;
+$form-check-input-border:                 1px solid rgba($black, .25) !default;
 $form-check-input-border-radius:          .25em !default;
 $form-check-radio-border-radius:          50% !default;
 $form-check-input-focus-border:           $input-focus-border-color !default;
@@ -902,8 +902,8 @@ $form-validation-states: (
 $zindex-dropdown:                   1000 !default;
 $zindex-sticky:                     1020 !default;
 $zindex-fixed:                      1030 !default;
-$zindex-offcanvas:                  1040 !default;
-$zindex-modal-backdrop:             1050 !default;
+$zindex-modal-backdrop:             1040 !default;
+$zindex-offcanvas:                  1050 !default;
 $zindex-modal:                      1060 !default;
 $zindex-popover:                    1070 !default;
 $zindex-tooltip:                    1080 !default;
@@ -917,8 +917,8 @@ $nav-link-padding-y:                .5rem !default;
 $nav-link-padding-x:                1rem !default;
 $nav-link-font-size:                null !default;
 $nav-link-font-weight:              null !default;
-$nav-link-color:                    null !default;
-$nav-link-hover-color:              null !default;
+$nav-link-color:                    $link-color !default;
+$nav-link-hover-color:              $link-hover-color !default;
 $nav-link-transition:               color .15s ease-in-out, background-color .15s ease-in-out, border-color .15s ease-in-out !default;
 $nav-link-disabled-color:           $gray-600 !default;
 
@@ -1125,7 +1125,7 @@ $accordion-icon-width:                    1.25rem !default;
 $accordion-icon-color:                    $accordion-color !default;
 $accordion-icon-active-color:             $accordion-button-active-color !default;
 $accordion-icon-transition:               transform .2s ease-in-out !default;
-$accordion-icon-transform:                rotate(180deg) !default;
+$accordion-icon-transform:                rotate(-180deg) !default;
 
 $accordion-button-icon:         url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$accordion-icon-color}'><path fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/></svg>") !default;
 $accordion-button-active-icon:  url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$accordion-icon-active-color}'><path fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/></svg>") !default;
@@ -1406,6 +1406,7 @@ $carousel-dark-control-icon-filter:  invert(1) grayscale(100) !default;
 // scss-docs-start spinner-variables
 $spinner-width:           2rem !default;
 $spinner-height:          $spinner-width !default;
+$spinner-vertical-align:  -.125em !default;
 $spinner-border-width:    .25em !default;
 $spinner-animation-speed: .75s !default;
 
@@ -1446,7 +1447,6 @@ $offcanvas-border-width:            $modal-content-border-width !default;
 $offcanvas-title-line-height:       $modal-title-line-height !default;
 $offcanvas-bg-color:                $modal-content-bg !default;
 $offcanvas-color:                   $modal-content-color !default;
-$offcanvas-body-backdrop-color:     rgba($modal-backdrop-bg, $modal-backdrop-opacity) !default;
 $offcanvas-box-shadow:              $modal-content-box-shadow-xs !default;
 // scss-docs-end offcanvas-variables
 
diff --git a/assets/stylesheets/bootstrap/bootstrap-utilities.scss b/assets/stylesheets/bootstrap/bootstrap-utilities.scss
index 9331d80..8ddb861 100644
--- a/assets/stylesheets/bootstrap/bootstrap-utilities.scss
+++ b/assets/stylesheets/bootstrap/bootstrap-utilities.scss
@@ -1,5 +1,5 @@
 /*!
- * Bootstrap Utilities v5.0.0-beta3 (https://getbootstrap.com/)
+ * Bootstrap Utilities v5.0.0 (https://getbootstrap.com/)
  * Copyright 2011-2021 The Bootstrap Authors
  * Copyright 2011-2021 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/main/LICENSE)
diff --git a/assets/stylesheets/bootstrap/forms/_form-control.scss b/assets/stylesheets/bootstrap/forms/_form-control.scss
index 9728b91..5e43aea 100644
--- a/assets/stylesheets/bootstrap/forms/_form-control.scss
+++ b/assets/stylesheets/bootstrap/forms/_form-control.scss
@@ -25,7 +25,7 @@
   &[type="file"] {
     overflow: hidden; // prevent pseudo element button overlap
 
-    &:not(:disabled):not([readonly]) {
+    &:not(:disabled):not(:read-only) {
       cursor: pointer;
     }
   }
@@ -65,7 +65,7 @@
   // 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] {
+  &:read-only {
     background-color: $input-disabled-bg;
     border-color: $input-disabled-border-color;
     // iOS fix for unreadable disabled content; see https://github.com/twbs/bootstrap/issues/11655.
@@ -88,7 +88,7 @@
     @include transition($btn-transition);
   }
 
-  &:hover:not(:disabled):not([readonly])::file-selector-button {
+  &:hover:not(:disabled):not(:read-only)::file-selector-button {
     background-color: $form-file-button-hover-bg;
   }
 
@@ -107,7 +107,7 @@
     @include transition($btn-transition);
   }
 
-  &:hover:not(:disabled):not([readonly])::-webkit-file-upload-button {
+  &:hover:not(:disabled):not(:read-only)::-webkit-file-upload-button {
     background-color: $form-file-button-hover-bg;
   }
 }
@@ -203,7 +203,7 @@ textarea {
   height: auto; // Override fixed browser height
   padding: $input-padding-y;
 
-  &:not(:disabled):not([readonly]) {
+  &:not(:disabled):not(:read-only) {
     cursor: pointer;
   }
 
diff --git a/assets/stylesheets/bootstrap/mixins/_color-scheme.scss b/assets/stylesheets/bootstrap/mixins/_color-scheme.scss
new file mode 100644
index 0000000..90497aa
--- /dev/null
+++ b/assets/stylesheets/bootstrap/mixins/_color-scheme.scss
@@ -0,0 +1,7 @@
+// scss-docs-start mixin-color-scheme
+@mixin color-scheme($name) {
+  @media (prefers-color-scheme: #{$name}) {
+    @content;
+  }
+}
+// scss-docs-end mixin-color-scheme
diff --git a/assets/stylesheets/bootstrap/mixins/_forms.scss b/assets/stylesheets/bootstrap/mixins/_forms.scss
index a1e0849..283462f 100644
--- a/assets/stylesheets/bootstrap/mixins/_forms.scss
+++ b/assets/stylesheets/bootstrap/mixins/_forms.scss
@@ -88,10 +88,13 @@
       border-color: $color;
 
       @if $enable-validation-icons {
-        padding-right: $form-select-feedback-icon-padding-end;
-        background-image: escape-svg($form-select-indicator), escape-svg($icon);
-        background-position: $form-select-bg-position, $form-select-feedback-icon-position;
-        background-size: $form-select-bg-size, $form-select-feedback-icon-size;
+        &:not([multiple]):not([size]),
+        &:not([multiple])[size="1"] {
+          padding-right: $form-select-feedback-icon-padding-end;
+          background-image: escape-svg($form-select-indicator), escape-svg($icon);
+          background-position: $form-select-bg-position, $form-select-feedback-icon-position;
+          background-size: $form-select-bg-size, $form-select-feedback-icon-size;
+        }
       }
 
       &:focus {
diff --git a/assets/stylesheets/bootstrap/mixins/_grid.scss b/assets/stylesheets/bootstrap/mixins/_grid.scss
index 92bb88a..d757eac 100644
--- a/assets/stylesheets/bootstrap/mixins/_grid.scss
+++ b/assets/stylesheets/bootstrap/mixins/_grid.scss
@@ -26,9 +26,14 @@
   margin-top: var(--#{$variable-prefix}gutter-y);
 }
 
-@mixin make-col($size, $columns: $grid-columns) {
-  flex: 0 0 auto;
-  width: percentage($size / $columns);
+@mixin make-col($size: false, $columns: $grid-columns) {
+  @if $size {
+    flex: 0 0 auto;
+    width: percentage($size / $columns);
+  } @else {
+    flex: 1 1 0;
+    max-width: 100%;
+  }
 }
 
 @mixin make-col-auto() {