The kind of thing I want, is actually on the grav website already (sort of, it’s a pretty boring / bad version, but it’s functionally the same thing) - Themes | Grav CMS (getgrav.org)
Except… it doesn’t work? When you choose ‘blog’ or ‘portfolio’ it doesn’t actually update the filter?
I found another grav site (a photography portfolio, but I can’t remember the link for it) which had the same problem (filters didn’t actually work) but I thought it was just an old site that hadn’t been updated/fixed in a while.
But does this system just… not work in grav? Especially as grav’s own site has the bug, which isn’t great for the website for a website-builder lol.