I didn't dig into whether this was using CSS or Javascript, but the animations and transistions used on this page were subtle and beautiful. The TOC on the left

I didn't dig into whether this was using CSS or Javascript, but the animations and transistions used on this page were subtle and beautiful. The TOC on the left being both interactive and dynamic made it a pleasure to scroll (without scroll hijacking). I'm digging the new era of presentation now that we've got the excessive transitions out of our system. It's subtle but still has some character. Well done to the team that put this together.