The at-rule() function in @supports tests whether a browser supports a given at-rule, like at-rule(@scope), and works in the supports() function of @import. The overscroll-behavior properties gain a chain value: scrolling passes to another scrollable area without the default bounce. Animation.reverse() now plays an animation with playbackRate 0. Behind flags: ML-KEM in Web Crypto and notification navigate.
developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/157