Fix display issues of close button in contextual light and dark modes

scss/_close.scss

@@ -12,7 +12,6 @@
   --#{$prefix}btn-close-focus-shadow: #{$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;
@@ -21,6 +20,7 @@
   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);
@@ -47,17 +47,20 @@
 }
 
 @mixin btn-close-white() {
-  filter: var(--#{$prefix}btn-close-white-filter);
+  --#{$prefix}btn-close-filter: #{$btn-close-filter-dark};
 }
 
 .btn-close-white {
   @include btn-close-white();
 }
 
+:root,
+[data-bs-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

@@ -94,3 +94,9 @@ $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:   $carousel-dark-control-icon-filter !default;
+
+//
+// Close button
+//
+
+$btn-close-filter-dark:             $btn-close-white-filter !default;

scss/_variables.scss

@@ -1713,7 +1713,8 @@ $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 v5.3.4
 // scss-docs-end close-variables
 
 

site/content/docs/5.3/components/close-button.md

@@ -6,49 +6,70 @@ group: components
 toc: true
 ---
 
-## Example
-
-Provide an option to dismiss or close a component with `.btn-close`. Default styling is limited, but highly customizable. Modify the Sass variables to replace the default `background-image`. **Be sure to include text for screen readers**, as we've done with `aria-label`.
+## Basic Close Button
 
 {{< example >}}
 <button type="button" class="btn-close" aria-label="Close"></button>
 {{< /example >}}
 
-## Disabled state
-
-Disabled close buttons change their `opacity`. We've also applied `pointer-events: none` and `user-select: none` to preventing hover and active states from triggering.
+## Dark Variant
 
 {{< example >}}
-<button type="button" class="btn-close" disabled aria-label="Close"></button>
+<div class="bg-dark p-2">
+  <button type="button" class="btn-close btn-close-white" aria-label="Close"></button>
+</div>
 {{< /example >}}
 
-## Dark variant
+## Dark
 
-{{< deprecated-in "5.3.0" >}}
-
-{{< callout warning >}}
-**Heads up!** As of v5.3.0, the `.btn-close-white` class is deprecated. Instead, use `data-bs-theme="dark"` to change the color mode of the close button.
-{{< /callout >}}
+{{< example >}}
+<div data-bs-theme="dark" class="bg-body p-2">
+  <button type="button" class="btn-close" aria-label="Close"></button>
+</div>
+{{< /example >}}
 
-Add `data-bs-theme="dark"` to the `.btn-close`, or to its parent element, to invert the close button. This uses the `filter` property to invert the `background-image` without overriding its value.
+## Light
 
-{{< example class="bg-dark" >}}
-<div data-bs-theme="dark">
+{{< example >}}
+<div data-bs-theme="light" class="bg-body p-2">
   <button type="button" class="btn-close" aria-label="Close"></button>
-  <button type="button" class="btn-close" disabled aria-label="Close"></button>
 </div>
 {{< /example >}}
 
-## CSS
+## Light in dark
 
-### Variables
+{{< example >}}
+<div data-bs-theme="dark" class="bg-body p-2">
+  <div data-bs-theme="light" class="bg-body p-2">
+    <button type="button" class="btn-close" aria-label="Close"></button>
+  </div>
+</div>
+{{< /example >}}
 
-{{< added-in "5.3.0" >}}
+## Dark in light
 
-As part of Bootstrap's evolving CSS variables approach, close button now uses local CSS variables on `.btn-close` for enhanced real-time customization. Values for the CSS variables are set via Sass, so Sass customization is still supported, too.
+{{< example >}}
+<div data-bs-theme="light" class="bg-body p-2">
+  <div data-bs-theme="dark" class="bg-body p-2">
+    <button type="button" class="btn-close" aria-label="Close"></button>
+  </div>
+</div>
+{{< /example >}}
 
-{{< scss-docs name="close-css-vars" file="scss/_close.scss" >}}
+## Toast and Close Button issue
 
-### Sass variables
+Forcing `data-bs-theme="light"` didn't work in dark mode. Now, the cross button is always dark.
 
-{{< scss-docs name="close-variables" file="scss/_variables.scss" >}}
+{{< example >}}
+<div class="toast" role="alert" aria-live="assertive" aria-atomic="true">
+  <div class="toast-header bg-warning" data-bs-theme="light">
+    <img src="..." class="rounded me-2" alt="...">
+    <strong class="me-auto">Warning!</strong>
+    <small>11 mins ago</small>
+    <button type="button" class="btn-close" data-bs-dismiss="toast" aria-label="Close"></button>
+  </div>
+  <div class="toast-body">
+    This is a warning message.
+  </div>
+</div>
+{{< /example >}}