I am showing a modal popup using CSS3 transitions (largely borrowed from Effeckt.css). It works well in all modern browsers except Safari. In Safari, the movement is OK, but
I found this issue when trying to find a solution to a problem I was experiencing in Safari (Mac and iOS), where a y-rotated svg only displayed its right half for no apparent reason.
In my case, the svg was a child of a fixed-position div, and I found that both position: fixed and position: absolute on the parent caused half the svg to disappear.
Neither changing z indexes, perspective, nor translate-z seemed to solve the issue. But randomly, adding a new div around my svg and setting its background-color solved the problem. I hope this helps the next person :)