As a general rule, anything that affects appearances in JSF is handled by CSS. JSF figured that there was already something that worked, so why re-invent it?
Of course, JSF View Definition Language is a higher-level VDL than raw HTML is, so there are often specialized sub-component CSS attributes such as the ones that Louis mentioned.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.
