[lyptt]

I'd love to see something like constraint layouts in pure CSS. It's an incredibly powerful tool when building user interfaces.

I was really excited to see GSS (http://gss.github.io), however at the time it was far too slow to be usable in real projects.

[moritzwarhier]

That's the argument for container queries, in my view.

I imagine container queries will totally change the way I write CSS as soon they are broadly supported.

Of course this would not make for a truly constrained-based layout definition. But it would at least make working this way somewhat possible.

The example where flex-directon is switched using a container query is spot-on. That's exactly ly what I sometimes miss being able to do in HTML+CSS.

Apparently there is a JS polyfill (awesome given the problem) but I haven't tried it and I assume the performance implications are bad.