A browsers has some preset styles already. A reset will remove all/most of them. Be wary however as if you have been marking up without a reset other things can/will change.
Get a Reset -> drop the ‘float: left’ from ‘.mini li’, ‘.mini a’ and ‘ul li’. You little menu will look just right, but a lot of other things will appear incorrect (main menu and a lot of other positioning).
I believe there are still a few basics you need to cover with HTML / CSS. You may be using a few too many floats :)