[mazugrin2]

I just found out today that Firefox does not yet support the css has() selector, while Chrome has supported it for over a year now. I get that there are a lot of reasons for this, but it surprised me, I guess.

I use Firefox because its fullscreen mode is far better than all the other browsers I've tried on Linux, but it does seem like it's clearly slower to perform and slower to be able to adopt new web 'quasi'-standards.

[kevincox]

:has() is Chromium-only right now. Firefox and Safari both have it in preview builds and it is scheduled to be released soon on both.

This is why having more browser diversity is important. We can't have people thinking that "the web" has a feature once Chrome releases it.