body {
	background-color: black;
	margin: 0;
	position: absolute;
	top: 0; right: 0; left: 0; bottom: 0;
}

#center {
	display: flex;
	justify-content: center;
}

#grid {
	line-height: 0;
}

#grid .square {
	width: 20px;
	height: 20px;
	background-color: #363636;
	margin: 1px;
	display: inline-block;
}
#grid .square.red { background-color: #ff3131; }
#grid .square.blue { background-color: #3838ff; }