You'll be surprised how often logic is needed. Can you automatically compute pixels or colors with CSS based on values of other elements in CSS? Or combined wi

You'll be surprised how often logic is needed. Can you automatically compute pixels or colors with CSS based on values of other elements in CSS? Or combined with values coming from a user's preferences? Seemingly trivial logic can reduce presentation complexity enormously. With a powerful programming language you have a better grip over the complexity than you do with CSS.