🔧 I Crashed a Mobile Browser With One CSS Property. Here's What I Learned About Rendering.

A few months ago, I was debugging a checkout flow on mobile. Everything looked fine on desktop — smooth step transitions, nice fade-ins, snappy UI. Then QA pinged me: "the payment page freezes on iPhone SE for ~2 seconds when opening."

I opened Web Inspector, navigated to the Layers panel, and my jaw dropped. What should have been 3–4 composite...