But it jumps around and flickers pretty bad. Chrome’s own demos in the docs don’t work at all.

https://developer.chrome.com/docs/css-ui/scroll-driven-anima...

Edit: Their reference works and has some really nice demos. Must be an iframe problem. https://scroll-driven-animations.style/#demos

Only on iOS 26.

I don’t think it did for me. Are you on iOS 26?