Header Question for WP Twenty Twelve Theme

In the CSS, or wherever it is, how do I remove the space between the header and the top of the page. In other words, I want no padding between the top of the header and top of the page.

Thanks guys, I've searched online but I cant afford to spend hours trying to figure it out.

THis is for Twenty Twelve Theme.

 

In the file style.css, find

body .site { 

Code (markup):

and delete the following:

margin-top: 48px;
margin-top: 3.428571429rem;

Code (markup):

That should do it.

 

Ah I must have missed it. It's was late at night when I was looking for it.

Thanks. Spasibo!
Mike.