Sandbox v1.6 & Header Top Margin.

I am trying to eliminate the white space gap at the very top of the screen between the browser toolbar and the header area. My header area has a black background so the white space and the black background with a gap there doesn’t look the way I need it to. I have tried this:

div#header,div#footer {
background-color: black;
color: green;
text-align:center;
margin: 0;
padding: 0;
}

[Please post code & CSS snippets between backticks or use the code button.]

My site can be located here http://www.sepsserver.com/sandbox/. How can this gap be eliminated?

Thank you,
Eric S.