CSS namespaces

While testing how hard it will be to bring my site into pier I discovered some css class clashes. For people it is quite normal to assign classes like header, footer and the like. In my opinion a cms like pier should try to step out of the way of any usage conflict. Therefor I would propose to namespace the css classes. A pr_header, pr_footer will do I think. Or do I missunderstand something completely? For me it was not possible to reconstruct our layout without haveing to remove all librares for the application. But then it is tedious to work with pier as the edit boxes and stuff are too small. What is the best approach to bring in the own developed design and having pier still functioning? thanks, Norbert