Observed in Firefox 34, on Mac:
When flipping to .face.front z-index=1 / .face.back z-index=0, all behaves as expected, backface remains invisible.
However, the next flip, to .face.front z-index=0 / .face.back z-index=1, backface becomes visible, resulting in an awkward transition, and in the case of no card face to be shown, instead of being invisible it shows the back of the rotated card.
Need to rethink z-indexing, which was implemented primarily to support IE8-10.
Observed in Firefox 34, on Mac: When flipping to .face.front z-index=1 / .face.back z-index=0, all behaves as expected, backface remains invisible. However, the next flip, to .face.front z-index=0 / .face.back z-index=1, backface becomes visible, resulting in an awkward transition, and in the case of no card face to be shown, instead of being invisible it shows the back of the rotated card.
Need to rethink z-indexing, which was implemented primarily to support IE8-10.