> CSS makes the common things that nearly everyone wants to do unnecessarily hard.

I'd like a list of those, along with a solution for each item in that list.[1]

A CSS cheat-sheet, if you will.

[1] I remember it common things being unnecessarily arcane, but since flexbox and grid, I can't think of any problems I might have. Although, take my words with a barrel of salt, because I am in no way an experienced CSS user.