CSS has a range of inbuilt functions. In this module you will find out about some of the key functions, and how to use them.| web.dev
An exploration of the newly supported at-rule for explicitly defining and animating custom properties in CSS.| ryanmulligan.dev
@bramus/style-observer is a MutationObserver for CSS. It allows you to attach JavaScript callbacks to changes in computed values of CSS properties| Bram.us