*
{
	margin: 0;
	padding: 0;
	box-sizing: border-box;
}

html, body
{
	width: 100%;
	height: 100%;
}

#canvas
{
	width: 800px;
	height: 800px;

	margin-left:auto;
	margin-right:auto;
	margin-top:auto;
	margin-bottom:auto;
	position:absolute;
	left:0;
	right:0;
	top:0;
	bottom:0;

	border: 1px solid black;
}