How I Fixed Transparent Video Alpha in Playwright...

How I Fixed Transparent Video Alpha in Playwright Using 1970s Film Math I've been building a content engine that renders HTML/CSS graphics to transparent video overlays — the kind you drop on a timeline in CapCut or Premiere with a drop shadow, gradient text, and a glow. Clean, professional, automated. It worked great in the browser. It worked fine as a WebM preview. And then the moment I imported it into any video editor, every single shadow and glow rendered as a solid colored blob. Days of de