Leverage Default CSS Classes
Don’t just rip out or change CSS classes without good reason for doing so. Think about it. While many front-end developers and web designers gasp at the sight of all the CSS classes that Drupal makes available, there really is a purpose to the madness. These classes (especially body classes) not only provide helpful information that guides you through figuring out what is generating the markup and what characteristics the contents of a given
<div> might have, but they are designed to give you the opportunity to do a large portion of your theme development within the CSS.
Keep in mind, especially when using contributed modules, that you will need to update and likely upgrade your site at some point in the future, and that you can’t control the changes that may be made to templates and often to the classes applied inside them. It’s also important to note that modules may rely on classes and certain CSS files, such as
system.base.css to be loaded in order to function properly. Of course, you can try to manage these things, but we can report from experience that this can easily turn into a frustrating waste of time. We’re not saying there’s not room for improvement or that you shouldn’t code your site the way you want to. We simply want to make you aware of some of the risks involved when stripping markup down to barebones.