CSS class names should usually be “semantic” (describing the meaning of the styled areas, e.g. “article-title”, “author-info”, “errror-message”, not “structural” (e.g. “left-side-navbar”, “small-title”).

…and they definitely shouldn’t explicitly describe the styling. I’ve seen a class names like “bold-red-12pt”. If you’re going to do that, you might as well just use inline font tags.

This article explains it much better than I can…