fix(Close): display issues of the close button in contextual light and dark modes

Author: mrholek

scss/_close.scss

@@ -2,6 +2,7 @@
 @use "mixins/border-radius" as *;
 @use "mixins/color-mode" as *;
 @use "variables" as *;
+@use "variables-dark" as *;
 
 // Transparent background and border properties included for button version.
 // iOS requires the button element instead of an anchor tag.
@@ -17,7 +18,6 @@
   --#{$prefix}btn-close-focus-shadow: #{$btn-close-focus-shadow};
   --#{$prefix}btn-close-focus-opacity: #{$btn-close-focus-opacity};
   --#{$prefix}btn-close-disabled-opacity: #{$btn-close-disabled-opacity};
-  --#{$prefix}btn-close-white-filter: #{$btn-close-white-filter};
   // scss-docs-end close-css-vars
 
   box-sizing: content-box;
@@ -26,6 +26,7 @@
   padding: $btn-close-padding-y $btn-close-padding-x;
   color: var(--#{$prefix}btn-close-color);
   background: transparent var(--#{$prefix}btn-close-bg) center / $btn-close-width auto no-repeat; // include transparent for button elements
+  filter: var(--#{$prefix}btn-close-filter);
   border: 0; // for button elements
   @include border-radius();
   opacity: var(--#{$prefix}btn-close-opacity);
@@ -52,18 +53,20 @@
 }
 
 @mixin btn-close-white() {
-  filter: var(--#{$prefix}btn-close-white-filter);
+  --#{$prefix}btn-close-filter: #{$btn-close-filter-dark};
 }
 
-.btn-close[data#{$data-infix}theme="dark"],
 .btn-close-white {
   @include btn-close-white();
 }
 
+:root,
+[data-coreui-theme="light"] {
+  --#{$prefix}btn-close-filter: #{$btn-close-filter};
+}
+
 @if $enable-dark-mode {
-  @include color-mode(dark) {
-    .btn-close {
-      @include btn-close-white();
-    }
+  @include color-mode(dark, true) {
+    @include btn-close-white();
   }
 }

scss/_variables-dark.scss

@@ -146,7 +146,6 @@ $accordion-icon-active-color-dark:  $primary-text-emphasis-dark !default;
 
 $accordion-button-icon-dark:         url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$accordion-icon-color-dark}'><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-.708'/></svg>") !default;
 $accordion-button-active-icon-dark:  url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$accordion-icon-active-color-dark}'><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-.708'/></svg>") !default;
-// scss-docs-end sass-dark-mode-vars
 
 
 //
@@ -155,4 +154,12 @@ $accordion-button-active-icon-dark:  url("data:image/svg+xml,<svg xmlns='http://
 
 $carousel-indicator-active-bg-dark:   $carousel-dark-indicator-active-bg !default;
 $carousel-caption-color-dark:         $carousel-dark-caption-color !default;
-$carousel-control-icon-filter-dark:   $carousel-dark-control-icon-filter !default;
+$carousel-control-icon-filter-dark:   $carousel-dark-control-icon-filter !default;
+
+
+//
+// Close button
+//
+
+$btn-close-filter-dark:             $btn-close-white-filter !default;
+// scss-docs-end sass-dark-mode-vars

scss/_variables.scss

@@ -2032,7 +2032,8 @@ $btn-close-opacity:          .5 !default;
 $btn-close-hover-opacity:    .75 !default;
 $btn-close-focus-opacity:    1 !default;
 $btn-close-disabled-opacity: .25 !default;
-$btn-close-white-filter:     invert(1) grayscale(100%) brightness(200%) !default;
+$btn-close-filter:           null !default;
+$btn-close-white-filter:     invert(1) grayscale(100%) brightness(200%) !default; // Deprecated in v5.3.2
 // scss-docs-end close-variables