- vendor prefixes

Haven't needed [-moz- & -o- for a while for transforms](http://caniuse.com/#feat=transforms2d) for a while.  (I assume you don't worry about old browsers since you didn't polyfill others.
Fx 23 removed prefix for [requestAnimationFrame](http://caniuse.com/#search=requestAnimationFrame).  Might be worth leaving for webkit.