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

    main {
    	height: 100%;
    	width: 100%;
    	background: #e2e2e2;
    	padding: 100px 0;
    }

    canvas {
    	display: block;
    	background: #000;
    	margin: 0 auto;
    }

    .button {
    	text-align: center;
    	padding: 20px;
    }