[cubefox]

Not sure CSS is really moving that much. E.g. doing a CSS transition from/to height:auto is still not supported.

[benfrain]

You can achieve that with grid right now. Set a row to height zero, with a container inside with overflow: hidden, then toggle that row to height 1fr. Stick whatever transition you want on it — job done

[cubefox]

Thanks. A lot of things are possible with tricks that should have long been supported natively.