html, body {
    margin: 0;
    padding: 0;
    overflow: hidden; /* prevents scrollbars */
    height: 100%;
    width: 100%;
}
canvas {
    display: block; /* removes inline gap */
    position: fixed; /* stay fixed on screen */
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}