The dark red is the background color of the div tag. The background of the page is white. If there is no white showing and the scroll bars are inactive, then it works! The body needs to be given a height of 100%, and div needs to be given absolute positioning along with 100% for width and height.

The code:

body {
	background-color: #fff;
	margin: 0;
	padding: 0;
	height: 100%;
}
#content {
	background-color: #300;
	color: #fff;
	height: 100%;
	position: absolute;
	width: 100%;
}