v5: Forms update (#28450)

* Initial spike of consolidated form checks

* Stub out forms rearrangement

- Prepping to drop non-custom file and range inputs
- Prepping to merge custom and native checks and radios (with switches)
- Prepping to merge custom select with form select
- Moving docs arround so forms has it's own area given volume of CSS

* Move input group Sass file to forms subdir

* Start to split and move the docs around

* Simpler imports

* Copyediting

* delete overview file

* Remove commented out code

* remove the custom-forms import

* rewrite flex-check as form-check, replace all custom properties

* Remove old forms doc

* stub out new subpage link section

* update migration guide

* Update nav, forms overview in page nav, and descriptions

* fix check bg position

* fix margin-top calculation

* rename .custom-select to .form-select

* Update validation styles for new checks

* add some vertical margin, fix inline checks

* fix docs examples

* better way to do this contents stuff, redo the toc while i'm at it

* page restyle for docs while here

* un-callout that, edit text

* redo padding on toc

* fix toc

* start to cleanup checks docs

* Rewrite Markdown tables into HTML

* Redesign tables, redo their docs

* Replace Open Iconic icons with custom Bootstrap icons

* Redesign the docs navbar, add a subheader, redo the sidebar

* Redesign docs homepage a bit

* Simplify table style overrides for docs tables

* Simplify docs typography for page titles and reading line length

* Stub out icons page

* Part of sidebar update, remove migration from nav.yml

* Move toc CSS to separate partial

* Change appearance of overview page

* fix sidebar arrow direction

* Add footer to docs layout

* Update descriptions

* Drop the .form-group class for margin utilities

* Remove lingering form-group-margin-bottom var

* improve footer spacing

* add headings to range page

* uncomment form range css

* Rename .custom-range to .form-range

* Drop unused docs var

* Uncomment the comment

* Remove unused variable

* Fix radio image sizing

* Reboot update: reset horizontal ul and ol padding

* de-dupe IDs

* tweak toc styles

* nvm, fix dropdown versions stuff

* remove sidebar nav toggle for now

* broken html

* fix more broken html, move css

* scss linting

* comment out broken helper docs

* scope styles

* scope styles

* Fixes #25540 and fixes #26407 for v5 only

* Update sidebar once more

* Match new sidenav order

* fix syntax error

* Rename custom-file to form-file, update paths, update migration docs for previous changes in #28696

* rename back

* fix size and alignment

* rename that back too

1 files changed, 142 insertions, 0 deletions

diff --git a/scss/forms/_form-range.scss b/scss/forms/_form-range.scss
new file mode 100644
index 000000000..b54d4d6aa
--- /dev/null
+++ b/scss/forms/_form-range.scss
@@ -0,0 +1,142 @@
+// Range
+//
+// Style range inputs the same across browsers. Vendor-specific rules for pseudo
+// elements cannot be mixed. As such, there are no shared styles for focus or
+// active states on prefixed selectors.
+
+.form-range {
+  width: 100%;
+  height: calc(#{$form-range-thumb-height} + #{$form-range-thumb-focus-box-shadow-width * 2});
+  padding: 0; // Need to reset padding
+  background-color: transparent;
+  appearance: none;
+
+  &:focus {
+    outline: none;
+
+    // Pseudo-elements must be split across multiple rulesets to have an effect.
+    // No box-shadow() mixin for focus accessibility.
+    &::-webkit-slider-thumb { box-shadow: $form-range-thumb-focus-box-shadow; }
+    &::-moz-range-thumb     { box-shadow: $form-range-thumb-focus-box-shadow; }
+    &::-ms-thumb            { box-shadow: $form-range-thumb-focus-box-shadow; }
+  }
+
+  &::-moz-focus-outer {
+    border: 0;
+  }
+
+  &::-webkit-slider-thumb {
+    width: $form-range-thumb-width;
+    height: $form-range-thumb-height;
+    margin-top: ($form-range-track-height - $form-range-thumb-height) / 2; // Webkit specific
+    @include gradient-bg($form-range-thumb-bg);
+    border: $form-range-thumb-border;
+    @include border-radius($form-range-thumb-border-radius);
+    @include box-shadow($form-range-thumb-box-shadow);
+    @include transition($custom-forms-transition);
+    appearance: none;
+
+    &:active {
+      @include gradient-bg($form-range-thumb-active-bg);
+    }
+  }
+
+  &::-webkit-slider-runnable-track {
+    width: $form-range-track-width;
+    height: $form-range-track-height;
+    color: transparent; // Why?
+    cursor: $form-range-track-cursor;
+    background-color: $form-range-track-bg;
+    border-color: transparent;
+    @include border-radius($form-range-track-border-radius);
+    @include box-shadow($form-range-track-box-shadow);
+  }
+
+  &::-moz-range-thumb {
+    width: $form-range-thumb-width;
+    height: $form-range-thumb-height;
+    @include gradient-bg($form-range-thumb-bg);
+    border: $form-range-thumb-border;
+    @include border-radius($form-range-thumb-border-radius);
+    @include box-shadow($form-range-thumb-box-shadow);
+    @include transition($custom-forms-transition);
+    appearance: none;
+
+    &:active {
+      @include gradient-bg($form-range-thumb-active-bg);
+    }
+  }
+
+  &::-moz-range-track {
+    width: $form-range-track-width;
+    height: $form-range-track-height;
+    color: transparent;
+    cursor: $form-range-track-cursor;
+    background-color: $form-range-track-bg;
+    border-color: transparent; // Firefox specific?
+    @include border-radius($form-range-track-border-radius);
+    @include box-shadow($form-range-track-box-shadow);
+  }
+
+  &::-ms-thumb {
+    width: $form-range-thumb-width;
+    height: $form-range-thumb-height;
+    margin-top: 0; // Edge specific
+    margin-right: $form-range-thumb-focus-box-shadow-width; // Workaround that overflowed box-shadow is hidden.
+    margin-left: $form-range-thumb-focus-box-shadow-width;  // Workaround that overflowed box-shadow is hidden.
+    @include gradient-bg($form-range-thumb-bg);
+    border: $form-range-thumb-border;
+    @include border-radius($form-range-thumb-border-radius);
+    @include box-shadow($form-range-thumb-box-shadow);
+    @include transition($custom-forms-transition);
+    appearance: none;
+
+    &:active {
+      @include gradient-bg($form-range-thumb-active-bg);
+    }
+  }
+
+  &::-ms-track {
+    width: $form-range-track-width;
+    height: $form-range-track-height;
+    color: transparent;
+    cursor: $form-range-track-cursor;
+    background-color: transparent;
+    border-color: transparent;
+    border-width: $form-range-thumb-height / 2;
+    @include box-shadow($form-range-track-box-shadow);
+  }
+
+  &::-ms-fill-lower {
+    background-color: $form-range-track-bg;
+    @include border-radius($form-range-track-border-radius);
+  }
+
+  &::-ms-fill-upper {
+    margin-right: 15px; // arbitrary?
+    background-color: $form-range-track-bg;
+    @include border-radius($form-range-track-border-radius);
+  }
+
+  &:disabled {
+    &::-webkit-slider-thumb {
+      background-color: $form-range-thumb-disabled-bg;
+    }
+
+    &::-webkit-slider-runnable-track {
+      cursor: default;
+    }
+
+    &::-moz-range-thumb {
+      background-color: $form-range-thumb-disabled-bg;
+    }
+
+    &::-moz-range-track {
+      cursor: default;
+    }
+
+    &::-ms-thumb {
+      background-color: $form-range-thumb-disabled-bg;
+    }
+  }
+}