down to (someone or something)

In consideration of the most minute detail or inconsequential person. She's obsessing about every aspect of wedding planning, down to the shade of the ink on the invitations. Certainly, a change like this affects everyone, from CEOs down to homeless people, but few seem to care about the latter. I can't sleep unless I've balanced my checkbook down to the penny.

down to somebody/something

even including the last item of a whole list of people or things: Everybody was affected by the economic crisis, from the president down to the poorest citizen. ♢ She’s thought of everything down to the tiniest details!