Ah I came here to recommend Flexbox Froggy and Grid Garden! I didn't come across them until long after I needed them, which is really a tragedy, but I try to rectify it by linking them to everyone I come across who is learning css (which is a lot of people due to some Discords I'm in). They're adorable and wonderful, and if you don't use css frequently enough to keep the properties memorized, but do use it enough that it would be convenient to be slightly more familiar than needing to re-google constantly I recommend re-playing them once a year or so; they're honestly pretty fun just because they're so cute.