html,body {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

canvas {
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    max-width: 100%;
    max-height: 100%;
    margin: auto;
    overflow: auto;
    object-fit: contain;
    position: fixed;
}