Finally spent time understanding what's going on in https://dev.to/janeori/expert-css-the-cpu-hack-4ddj (but only for the main technique, not the way it is used for the demos in the article, like in the Game of Life demo — https://codepen.io/propjockey/pen/NWEYdjY (Chrome only)) Basically, re-evaluation of state in pure CSS (turing complete, all of that) using the interactions between animations and custom properties (and, currently, Chrome-only details of their implementation)