I met an engineer last week who, like me, is among the CSS-geeky. Upon discovering this shared ground, he asked if I knew the answer to an age-old puzzler: how to, using just HTML and CSS, put a fixed-width column on one side of a page and have a fluid column fill the rest of the width. (In other words, a navigation or sidebar column that’s ___px wide, and a main-content column that is as wide as the rest of the space.)
This comes up often because, as much as we all may sincerely speak of separating presentation and content, CSS still has profound limits in what it enables. Putting fixed and fluid side by side is a big one.