- Use a semitransparent gradient from light to dark which works on any background-color
- Store the gradient as a custom property (--bs-gradient)
- Remove `.bg-gradient-*` variants in favour of `.bg-gradient` which works even when `$enable-gradients` are enabled
- Add gradients to navbar, active page links and badges when gradients are enabled
- Drop hover and focus states
- Drop .badge-* variants and associated mixin for .bg-* utilities
- Drop .badge-pill for .rounded-pill utliity and adjust horizontal padding to find middle ground of .badge and old .badge-pill
- Remove unused variables
- Add default color value to .badge base class
- Update docs to reflect changes
I suggest removing `color: #FFF` from the `badge` class, because it is
provided by the `badge-<modifier>` classes along with a
background-color, whereas there is no corresponding background-color
provided on the `badge` class itself.
Background
----------
According to the documentation:
> [badge] Requires one of the contextual, color modifier classes for `color` and
> `background-color`.
That is, color and background color should be provided by a modifier
class, rather than the badge class itself.
e.g. `<span class='badge badge-primary'>4</span>`
In general, providing a `color` property without also providing a
`background-color` should be avoided. [W3 QA tips]
In this context, this is a problem only if someone creates a `badge`
without providing a modifier. Such an omition may be difficult to trouble-shoot,
because this will most likely yield white text on a white background.
[W3 QA tips](https://www.w3.org/QA/Tips/color)
