Bootstrap5 (#17)

* Bootstrap5 migration

dev/scss/bootstrap/_carousel.scss

@@ -3,12 +3,12 @@
 // 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
+// 2. The .carousel-item-start and .carousel-item-end 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
+// 4. .active.carousel-item-start and .active.carousel-item-end 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
+// 5. .carousel-item-next.carousel-item-start and .carousel-item-prev.carousel-item-end
 //    is the upcoming slide in transition.
 
 .carousel {
@@ -42,16 +42,19 @@
   display: block;
 }
 
-.carousel-item-next:not(.carousel-item-left),
-.active.carousel-item-right {
+/* rtl:begin:ignore */
+.carousel-item-next:not(.carousel-item-start),
+.active.carousel-item-end {
   transform: translateX(100%);
 }
 
-.carousel-item-prev:not(.carousel-item-right),
-.active.carousel-item-left {
+.carousel-item-prev:not(.carousel-item-end),
+.active.carousel-item-start {
   transform: translateX(-100%);
 }
 
+/* rtl:end:ignore */
+
 
 //
 // Alternate transitions
@@ -65,14 +68,14 @@
   }
 
   .carousel-item.active,
-  .carousel-item-next.carousel-item-left,
-  .carousel-item-prev.carousel-item-right {
+  .carousel-item-next.carousel-item-start,
+  .carousel-item-prev.carousel-item-end {
     z-index: 1;
     opacity: 1;
   }
 
-  .active.carousel-item-left,
-  .active.carousel-item-right {
+  .active.carousel-item-start,
+  .active.carousel-item-end {
     z-index: 0;
     opacity: 0;
     @include transition(opacity 0s $carousel-transition-duration);
@@ -95,13 +98,17 @@
   align-items: center; // 2. vertically center contents
   justify-content: center; // 3. horizontally center contents
   width: $carousel-control-width;
+  padding: 0;
   color: $carousel-control-color;
   text-align: center;
+  background: none;
+  border: 0;
   opacity: $carousel-control-opacity;
   @include transition($carousel-control-transition);
 
   // Hover/focus state
-  @include hover-focus() {
+  &:hover,
+  &:focus {
     color: $carousel-control-color;
     text-decoration: none;
     outline: 0;
@@ -110,15 +117,11 @@
 }
 .carousel-control-prev {
   left: 0;
-  @if $enable-gradients {
-    background-image: linear-gradient(90deg, rgba($black, .25), rgba($black, .001));
-  }
+  background-image: if($enable-gradients, linear-gradient(90deg, rgba($black, .25), rgba($black, .001)), null);
 }
 .carousel-control-next {
   right: 0;
-  @if $enable-gradients {
-    background-image: linear-gradient(270deg, rgba($black, .25), rgba($black, .001));
-  }
+  background-image: if($enable-gradients, linear-gradient(270deg, rgba($black, .25), rgba($black, .001)), null);
 }
 
 // Icons for within
@@ -127,8 +130,19 @@
   display: inline-block;
   width: $carousel-control-icon-width;
   height: $carousel-control-icon-width;
-  background: 50% / 100% 100% no-repeat;
+  background-repeat: no-repeat;
+  background-position: 50%;
+  background-size: 100% 100%;
 }
+
+/* rtl:options: {
+  "autoRename": true,
+  "stringMap":[ {
+    "name"    : "prev-next",
+    "search"  : "prev",
+    "replace" : "next"
+  } ]
+} */
 .carousel-control-prev-icon {
   background-image: escape-svg($carousel-control-prev-icon-bg);
 }
@@ -136,46 +150,48 @@
   background-image: escape-svg($carousel-control-next-icon-bg);
 }
 
-
-// Optional indicator pips
+// Optional indicator pips/controls
 //
-// Add an ordered list with the following class and add a list item for each
-// slide your carousel holds.
+// Add a container (such as a list) with the following class and add an item (ideally a focusable control,
+// like a button) with data-bs-target for each slide your carousel holds.
 
 .carousel-indicators {
   position: absolute;
   right: 0;
   bottom: 0;
   left: 0;
-  z-index: 15;
+  z-index: 2;
   display: flex;
   justify-content: center;
-  padding-left: 0; // override <ol> default
+  padding: 0;
   // Use the .carousel-control's width as margin so we don't overlay those
   margin-right: $carousel-control-width;
+  margin-bottom: 1rem;
   margin-left: $carousel-control-width;
   list-style: none;
 
-  li {
+  [data-bs-target] {
     box-sizing: content-box;
     flex: 0 1 auto;
     width: $carousel-indicator-width;
     height: $carousel-indicator-height;
+    padding: 0;
     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;
+    border: 0;
     // 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;
+    opacity: $carousel-indicator-opacity;
     @include transition($carousel-indicator-transition);
   }
 
   .active {
-    opacity: 1;
+    opacity: $carousel-indicator-active-opacity;
   }
 }
 
@@ -186,12 +202,28 @@
 
 .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;
+  right: (100% - $carousel-caption-width) * .5;
+  bottom: $carousel-caption-spacer;
+  left: (100% - $carousel-caption-width) * .5;
+  padding-top: $carousel-caption-padding-y;
+  padding-bottom: $carousel-caption-padding-y;
   color: $carousel-caption-color;
   text-align: center;
 }
+
+// Dark mode carousel
+
+.carousel-dark {
+  .carousel-control-prev-icon,
+  .carousel-control-next-icon {
+    filter: $carousel-dark-control-icon-filter;
+  }
+
+  .carousel-indicators [data-bs-target] {
+    background-color: $carousel-dark-indicator-active-bg;
+  }
+
+  .carousel-caption {
+    color: $carousel-dark-caption-color;
+  }
+}