All right, So I want to make my header go off page, there's a white space between the top and left of the page.
Not sure if this is relevant, but if you want the header to default to scrolling off the top out of view (on smaller screens) when the page is displayed, just link to an element below it. E.g.
<a href="mypage.html#rest">my page</a>
<link rel="stylesheet" type="text/css" href="theme.css" />
As I said, this may not be relevant, but it's a technique I use to make pages more suitable for small-screen mobiles as well as conventional PCs. The header is still there, but does not occupy valuable screen space (on smaller screens) unless you want it to. You can use media-specific code to actually suppress the header, if desired, but this is simpler.