Building Performant Expand & Collapse Animations

It’s starting to be pretty common knowledge that there are only 2 things you can animate cheaply in CSS: opacity and transforms. Anything else, you run a high risk of that animation/transition being choppy. Fortunately, there is a ton of animation possibility with those properties, especially since transform can move and resize elements any-which-way.
You can even get tricky and fake the animating of other properties with transforms. In this tutorial on the Google Chrome Developers Blog, Paul Lewis and …

Building Performant Expand & Collapse Animations is a post from CSS-Tricks

Link: https://developers.google.com/web/updates/2017/03/performant-expand-and-collapse