Use the unset keyword in CSS.
Use Custom Properties Queries in CSS
Use light and dark color schemes in all browsers
PostCSS plugin to unwrap nested rules like how Sass does it
Detect/remove browser hacks from CSS files.
Gamut map css colors to fit display specific gamuts
Merge CSS rules with PostCSS.
Parse CSS and add vendor prefixes to CSS rules using values from the Can I Use website
Correctly declare progressive enhancements for CSS Custom Properties.
Minify at-rule params with PostCSS
PostCSS plugin to use CSS Modules everywhere
Style form elements when they are empty
Use the :any-link pseudo-class in CSS
Ensure CSS selectors are unique.
A minimal CSS module shim
Use cascade layers in CSS
Use the :focus-within pseudo-selector in CSS
The Reference Element Pseudo-class: :scope
PostCSS plugin to transform :not() W3C CSS level 4 pseudo class to :not() CSS level 3 selectors
Discard duplicate rules in your CSS files with PostCSS.
Parse CSS color values
Declare a list of custom properties in a single at-property rule
Display resolution-dependent images using the image-set() function in CSS
Use Custom Media Queries in CSS