The logic is this: when you hover the block flips and shows the "reverse" side
In fact, the implementation of 3D flip card as Here
in chrome and Opera everything is fine, but in Firefox noticed a bug: when restoring a block is flipped using the transform rotate and transition, and shows the reverse side with the background image, but the image in the process of turning flickers, stops to flicker just turning.
if you set "front" of the block transform: rotateY(0deg) then the image does not flicker, and all the rules
What is the hack? And why is this behavior?
here is all the code in CodePen