body {
  background-color: lightblue;
}

html, body {
  width:  100%;
  height: 100%;
  margin: 0;
}

#shaderCanvas {
	position:absolute;
	left:0;
	top:0;
	margin:0;
	padding:0;
	width:100%;
	height:100%;
	background-color:purple;
}