"@supports (-webkit-animation-name)" would actually test true in pretty much every modern browser. See https://compat.spec.whatwg.org/#css-simple-aliases https

"@supports (-webkit-animation-name)" would actually test true in pretty much every modern browser. See https://compat.spec.whatwg.org/#css-simple-aliases https://compat.spec.whatwg.org/#css-simple-aliases But yes, your larger point that @supports is easy to misuse when targeting old prefixed stuff is certainly true. > animation-play-state, which just landed in Chrome (and I dare say Firefox) animation-play-state has been supported unprefixed in Firefox since Firefox 16, 4 years or so ago.