Thanks for finding that out. We (Firefox) fixed a box shadow performance bug [1] in Firefox 47, which will be released on June 7th. It looks like this site is h

Thanks for finding that out. We (Firefox) fixed a box shadow performance bug [1] in Firefox 47, which will be released on June 7th. It looks like this site is hitting that perf bug. [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1250947 https://bugzilla.mozilla.org/show_bug.cgi?id=1250947