@gaditb I voted the second option, but I would probably narrow it to "one stylesheet, probably written by hand (i.e. not Bootstrap or whatever, though a reset may be acceptable), with at most a trivial number of classes, probably no ID-specific rules".
@Lady @gaditb Sure, and of course in theory you can do arbitrary element names in lieu of IDs. I think it's neither necessary nor sufficient, but I would hazard a guess that I'd say most(?) websites that met that spec were at least brutalist-adjacent these days.