Issue with custom header

I am having a problem with a custom header I set up as you can see in the URL I linked.
It seems like the CSS is being applied/merged with the page content instead of just the header?
I don't know why this is happening. I am duplicating the steps I made to make this similar header layout on another site: http://w9ppe.hosts.cx/ and there is no issues with that one.

Thank you for your help.