Well, there are half and full adders, maybe a flip-flop would be feasible?
If we can introduce delay in the circuit it would be trivial to build FFs from Boolean-complete gate sets, thus sequential elements with memory. But AFAIK CSS if() can't introduce delays.
Keyframe animation?
If we can introduce delay in the circuit it would be trivial to build FFs from Boolean-complete gate sets, thus sequential elements with memory. But AFAIK CSS if() can't introduce delays.
Keyframe animation?