CSS review

so im trying my hand at CSS… normally i do everything in flash, but im liking what i see in the CSS world…
here’s what i have so far… http://designlev.com/1010/
I do have a bit of a problem… when you resize the browser things get a little distorted and i can’t figure out why. i attached the pic so you can see what i mean.
Any suggestions?

Also, i just wanted to see how the CSS looked… since im new at it, im not to hot at it and any feedback would be nice. the css file is http://designlev.com/1010/main.css