CSS/Headers Problem

Hi there,

I’m new to wordpress & have finally (almost) customized my wp to my website layout after many frustrating hours. But I can’t figure out why the Headers aren’t staying consistent on the comments page, archive, individual post view, etc. I know it’s something to do with my CSS but I need some help figuring this out! Hopefully a wonderful, brilliant person will be able to help me out! 🙂

http://www.canadianvagabond.com/

Thanks in advance!!!