Closes#23319. Both `.text-muted` and `.btn-outline-secondary` (and indeed all secondary items) make use of `$gray-600`. New value provides a contrast ratio of 4.69.
- Changes the wrapping label to a div so we can style the label instead of another element while also supporting form validation.
- Fixes form validation styles for custom file input (closes#24831).
- Updates docs with validation styles (also adding example feedback text while I was there) and new how it works section.
* Restyle code element, clean up variables
- Removes the padding and background-color
- Changes the color to a brand color ()
- Add new variables to kbd element styles to account for removing the code ones
- Remove overrides that were needed previously
* only break between words, and override it in the pre
* make file inputs 100% wide
* scope custom file changes in input group for sizing
* shorter button labels for responsive
* narrower cards
* button was too wide
* downsize
* fewer links in pagination
* redo cell text
* improve overflow docs
* match layout behaviors
* ditch the indicator as separate element for psuedo-elements on the label
* move disabled to attribute only on input
* redo default inline check to support new markup
* redo inline forms
* clean up vars
* update validation mixin to new structure
* update checks in docs
* linting for for/id attributes
* Add support for size attribute on custom selects
* Add large custom select, document it and the small variant
* fix custom select focus state
* fix custom file input focus styles
* remove empty line
* Update the form focus mixin to use a manual `$enable-shadows` check so we can always ensure a focus state for accessibility and consistency
* - Add new `$input-btn-focus-width` and `$input-btn-focus-color` variables.
- Replace separate `$btn-focus-box-shadow` and `$input-focus-box-shadow`
variables with unified `$input-btn-focus-box-shadow` to match our
combined variables approach elsewhere.
* Put new focus width var to use in buttons mixins
* use new button input-box shadow var
* Add a new mixin for quickly adding linear gradient to components when $enable-gradients is set to true
* use correct var
* fix focus shadows in button mixins
* Add opt-in gradients to alerts, buttons, carousel, custom radios and checkboxes, custom file input, and dropdown items
* Generate .bg-gradient- utilities
* add headings to colors page and document bg-gradient utils
* update the button color for active status, check with yiq as it's done for basic state and hover state
