Making CSS Turing complete, nice. Now we can run entire websites with functionality even if we turn JS off. Maybe we'll even see CSS only programming frameworks.
I wrote a game in CSS to demonstrate what you can do with it - https://codepen.io/onion2k/pen/qBbKYee (no mobile because I was too lazy to make it responsive). CSS is very powerful, but you need to do some weird stuff to get interactivity.