Truly, Devious (Truly Devious, #1)
by Maureen Johnson
3.5⭐. Takes a bit to give in to the sort of ridiculous setting, but it does get going in the second half. The problem with the love interest is that he's not at all interesting. I believe Stevie is into him, but when they have their romcom low moment, I didn't care that he was mad at her and was annoyed that she moped about it.
Is Leo supposed to be gay? There's nail polish, and at one point he calls himself a friend of Dorothy (he's referring to Dorothy Parker, not Oz), which (probably) would've been anachronistic.