Good point on CSS springs. There's actually been spec discussion around spring() as a timing function but the fundamental problem is springs are durationless, they settle when physics says so, not when a timer expires, and that breaks how CSS animations work under the hood. On Android, yes, since Android 12 the overscroll glow became a stretch-and-bounce and Material You uses spring/fling physics system-wide, less opinionated than iOS but it's there. And fair enough on the AI callout, I did use AI to clean up the writing, the ideas and code are mine though. I'll keep it more raw next time.