I like the principle, but sorry to be neg, but the execution is awful.<p>Stacks don&#x27;t slide sideways.<p>They pop and push and operate. That&#x27;s what you should animate, the <i>actions</i>.<p>Having the operator in the top left is very odd.<p>What&#x27;s that number for? The speed of the animation. Why bother, it is meaningless.