I have large CSS rules which are mainly based on CSS3 transitions.
When I check the rendering time for a typical page with online tools like webpagetest.org or developer tools like firebug; the rendering time is extremely different in various browsers. For example, MSIE: 1.5s, Chrome:2.5, FireFox:47.0.
How can I debug which part of my CSS has caused unusual problem in FireFox?
Common tools like firebug only shows the total rendering time, and does not show which process (DOM and its CSS rule) is slow and blocking.
How to find the slow process in CSS rendering of FireFox?