The Web Styling Challenge: you and another person are going to make a web site. You are doing the HTML, while the other person does the CSS (you can discuss it and swap jobs if you want). You can talk as much as you want ahead of time, but the only record you can keep is a table that maps CSS selectors to a description of what you'll be using them for. You are then split up and do your individual tasks. When you're finished, you will be judged on how broken the results of combining your pages with the other person's stylesheets are. I think just imagining how this game would go makes it pretty clear that CSS is lousy at separating the concerns of style and layout.