Lacking CSS tags

[Iceball457]

It would be awesome to have additional CSS styling tags! I'm trying to figure out how to access all the elements from CSS using GTK_DEBUG=interactive, but from what I can see a lot of elements simply don't have what I'm looking for...

Of course, it might just be a lack of documentation, but it would be nice to have .active on the currently selected category button!

It might be possible to select, for example, the whole bar that contains the categories with window.background box.vertical box.horizontal[2/6], but I couldn't get it working.

[teleportingtortoise]

Categories use :focused when selected, but there isn't a style for it by default and "All" doesn't start with the :focused state

I've added a PR that implements a lot of names and classes for CSS styling that will probably need some review first, but in the mean time you can style the category wrapper via window box.horizontal:nth-child(2) or window box.horizontal:nth-child(3) if you have the close button enabled. There's also a box inside that that fits to the button content.