I'm not a web developer, but I've built toy websites (without frameworks) and can do basic things in a few web frameworks. I remember when CSS was "invented". After a small amount of time, I could reasonably fit all of it in my head without needing to look anything up.

I looked at the CSS for the first codepen example, and it looks like gibberish to me.

Should we really have a mini animations programming language in the styling system? This seems like a bit much. More than a bit much.

Can't this be done with Javascript? I get that a lot of people have a knee-jerk negative reaction to using JS for everything, but it's a programming language... this is kinda its job.