Add dark mode support (#35857)

* Add dark mode to docs

* Minor fix: missing space indentation

* Minor fix: revert utilities/z-index added-in modification

* Remove prev: and next: from doc because extracted to another PR

* Use .bg-body-tertiary in all Utilities > Overflow examples

* fix example

* Fix up spacing examples

* Update box-shadow Sass variables and utilities to auto-adjust to color modes

* Remove unused docs class

* Refactor form styles to use CSS variable for background images on .form-check and .form-switch

* Fix docs selector

* Rename shortcut for clarity

* Heading consistency

* Reintroduce missing 4th grid item in Utilities > Spacing example

* Fix bundlewatch

* .bd-callout* rendering is OK so removing comments in the code

* Update scss/_utilities.scss

Co-authored-by: Julien Déramond <[email protected]>

* Fix gutters example styling

* Fix text colors on background utils docs

* redesign and fix up position marker example, which doesn't show nicely in darkmode but at least isn't broken

* fix some color utils examples

* Deprecate mixin notice

* Deprecate notice for list-group-item-variant() mixin

* Revamp new link CSS vars

* Use map-keys in some each Sass files

* Remove list-group-item-variant mixin ref in sass loop desc

* Display CSS vars scoped to our built-in dark mode

* Revert previous commit

* Fix list group variant link

* Fix typo

* Remove imports of alert/list-group mixins in scss/_mixins.scss

* Small formatting + comments removal in scss/_content.scss

* Fix alert links colors

* fix dropdown border-radius mixin

* fix link color and underline again, this time using CSS var override for color var and fallback value for the underline

* fix colors on docs navbar for dark mode

* remove two changes

* missing ref

* another link underline fix, just use sass vars for link decoration for now

* missing color bg docs, plus move dropdown override to scss

* more changes from review

* fix some examples, drop unused docs navbar styles, update docs navbar color mode to use mixin

* Few fixes around type

- Restored CSS variable for color on headings, this time with a fallback value
- In conjunction, restored and wrapped the default CSS var with a null value check
- Split headings and paragraphs docs in Reboot, elaborated on them

* Restyle custom details > summary element in docs

* Rewrite some migration docs

* fix form checks

* Fix up some navbar styling, tweak docs callout

* Fix select images, mostly for validation styling

* Clean up some migration notes, document some new form control CSS vars, mention new variables-dark in sass docs

* Update site/content/docs/5.2/components/scrollspy.md

Co-authored-by: Julien Déramond <[email protected]>

* Apply suggestions from code review

Co-authored-by: Julien Déramond <[email protected]>

* mention form control css vars in migration guide

* Tweak grid and flex docs background examples

* clarify some docs

* fix some more things

Co-authored-by: Julien Déramond <[email protected]>
Co-authored-by: Julien Déramond <[email protected]>

1 files changed, 70 insertions, 0 deletions

diff --git a/scss/_variables-dark.scss b/scss/_variables-dark.scss
new file mode 100644
index 000000000..9a3874fdc
--- /dev/null
+++ b/scss/_variables-dark.scss
@@ -0,0 +1,70 @@
+// Dark color mode variables
+//
+// Custom variables for the `[data-bs-theme="dark"]` theme. Use this as a starting point for your own custom color modes by creating a new theme-specific file like `_variables-dark.scss` and adding the variables you need.
+
+//
+// Global colors
+//
+
+// scss-docs-start sass-dark-mode-vars
+$primary-text-dark:                 $blue-300 !default;
+$secondary-text-dark:               $gray-300 !default;
+$success-text-dark:                 $green-300 !default;
+$info-text-dark:                    $cyan-300 !default;
+$warning-text-dark:                 $yellow-300 !default;
+$danger-text-dark:                  $red-300 !default;
+$light-text-dark:                   $gray-100 !default;
+$dark-text-dark:                    $gray-300 !default;
+
+$primary-bg-subtle-dark:            $blue-900 !default;
+$secondary-bg-subtle-dark:          $gray-900 !default;
+$success-bg-subtle-dark:            $green-900 !default;
+$info-bg-subtle-dark:               $cyan-900 !default;
+$warning-bg-subtle-dark:            $yellow-900 !default;
+$danger-bg-subtle-dark:             $red-900 !default;
+$light-bg-subtle-dark:              $gray-800 !default;
+$dark-bg-subtle-dark:               mix($gray-800, $black) !default;
+
+$primary-border-subtle-dark:        $blue-700 !default;
+$secondary-border-subtle-dark:      $gray-700 !default;
+$success-border-subtle-dark:        $green-700 !default;
+$info-border-subtle-dark:           $cyan-800 !default;
+$warning-border-subtle-dark:        $yellow-800 !default;
+$danger-border-subtle-dark:         $red-700 !default;
+$light-border-subtle-dark:          $gray-700 !default;
+$dark-border-subtle-dark:           $gray-800 !default;
+
+$body-color-dark:                   $gray-500 !default;
+$body-bg-dark:                      $gray-900 !default;
+$body-emphasis-color-dark:          $gray-100 !default;
+$body-secondary-color-dark:         rgba($body-color-dark, .75) !default;
+$body-secondary-bg-dark:            $gray-800 !default;
+$body-tertiary-color-dark:          rgba($body-color-dark, .5) !default;
+$body-tertiary-bg-dark:             mix($gray-800, $gray-900, 50%) !default;
+$emphasis-color-dark:               $white !default;
+$border-color-dark:                 $gray-700 !default;
+$border-color-translucent-dark:     rgba($white, .15) !default;
+$headings-color-dark:               #fff !default;
+$link-color-dark:                   $blue-300 !default;
+$link-hover-color-dark:             $blue-200 !default;
+$code-color-dark:                   $pink-300 !default;
+
+
+//
+// Forms
+//
+
+$form-select-indicator-color-dark:  $body-color-dark !default;
+$form-select-indicator-dark:        url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'><path fill='none' stroke='#{$form-select-indicator-color-dark}' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='m2 5 6 6 6-6'/></svg>") !default;
+
+$form-switch-color-dark:            rgba($white, .25) !default;
+$form-switch-bg-image-dark:         url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'><circle r='3' fill='#{$form-switch-color-dark}'/></svg>") !default;
+
+
+//
+// Accordion
+//
+
+$accordion-button-icon-dark:         url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$primary-text-dark}'><path fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/></svg>") !default;
+$accordion-button-active-icon-dark:  url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$primary-text-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-.708z'/></svg>") !default;
+// scss-docs-end sass-dark-mode-vars