html,
body {
    margin: 0;
    padding: 0;
    overflow: hidden;
}

canvas {
    display: block;
    position: absolute;
    top: 50%;
    left: 50%;
    -moz-transform: translateX(-50%) translateY(-50%);
    -webkit-transform: translateX(-50%) translateY(-50%);
    transform: translateX(-50%) translateY(-50%);
}