This PR adds support for utilities like:
- `text-shadow-lg/25`
It uses relative color syntax to replace the alpha value of the shadow
from your theme.
When combined with a colors:
- `text-shadow-lg/25 text-shadow-red-500`
- `text-shadow-lg/25 text-shadow-red-500/75`
The alpha values are **multiplied** resulting in a shadow with the color
specified in `--color-red-500` and alpha values of 25% and 18.75%
respectively.
1a68b99368