The animation-timeline CSS property specifies the timeline that is used to control the progress of a CSS animation.| MDN Web Docs
The @layer CSS at-rule is used to declare a cascade layer and can also be used to define the order of precedence in case of multiple cascade layers.| MDN Web Docs
The :where() CSS pseudo-class function takes a selector list as its argument, and selects any element that can be selected by one of the selectors in that list.| MDN Web Docs
The :is() CSS pseudo-class function takes a selector list as its argument, and selects any element that can be selected by one of the selectors in that list. This is useful for writing large selectors in a more compact form.| MDN Web Docs
CSS developers got the ultimate dream: container queries. But now that they are here, are we actually reaching for them as much as we thought we would?| frontendmasters.com
A proposal to define masonry and grid in different specifications.| Chrome for Developers
Learn how to use CSS container queries today.| ishadeed.com
The functional :has() CSS pseudo-class represents an element if any of the relative selectors that are passed as an argument match at least one element when anchored against this element. This pseudo-class presents a way of selecting a parent element or a previous sibling element with respect to a reference element by taking a relative selector list as an argument.| MDN Web Docs