I'm also excited to learn about calc(), but I've usually been able to use something like {position: relative; left: X%; margin-left: -Ypx;} to get stuff positio

I'm also excited to learn about calc(), but I've usually been able to use something like {position: relative; left: X%; margin-left: -Ypx;} to get stuff positioned with both percent and pixels. Though it's been tricky sometimes, there's always been some magical combination of width, left, margin, padding and maybe float to avoid resorting to JS for this so far; kinda curious when it would be necessary.