How to show posts with different .css in main page depending on category?

The idea is simple: I have different types of posts…

Article
Asides
Review
Videos
etc

…and I want them to look different from each other (depending on the category they are in) in both index and single pages.

Any ideas on how to achieve this?

[EDIT]

I almost forgot: I couldn’t find anything like this in the forums. If you do, please tell me what term did you search for, so I we can all learn 😉