Waaay back there used to be a Firebug plugin that would monitor which CSS was ever used as you interacted with a page. Worked great for exactly these dynamic pa

Waaay back there used to be a Firebug plugin that would monitor which CSS was ever used as you interacted with a page. Worked great for exactly these dynamic pages - I was using it with React for a few years before Quantum killed the XUL addons. I'd forgotten about it and am now wondering if anyone made a replacement...