html, body {
    margin: 0;
    padding: 0;
    border: 0 none;
    background-color: #2a2a2a;
}
#center_gamestar {
	position: absolute;
	width: 600px;
	height: 600px;
	left: 50%;
	top: 50%;
	margin-left: -300px;
	margin-top: -300px;
}