It's worth a note that these buttons are very laggy in MobileSafari, except for zoom-in and zoom-out, which use -webkit-transform and thus have hardware acceler

It's worth a note that these buttons are very laggy in MobileSafari, except for zoom-in and zoom-out, which use -webkit-transform and thus have hardware accelerated animation. While slide-* could be changed to use -webkit-transform, I'm somewhat surprised that the performance of the others is so bad, and I wonder if there's some not-completely-awful trick that would improve expand-*.