.noselect{-webkit-touch-callout:none;-webkit-user-select:none;-khtml-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none}.preserve-3d{transform-style:preserve-3d}.perspective{perspective:1000px}.rotate-flip{transform:rotateY(180deg)}.hidden-back{-webkit-backface-visibility:hidden;backface-visibility:hidden}