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

canvas {
    box-shadow: 1px 1px 10px rgba(0, 0, 0, 0.1),
    -2px 12px 10px rgba(0, 0, 0, 0.1);
    display: block;
    padding: 0;
    margin: auto;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}