body {
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}

#canvas-holder {
    display: flex;
    align-items: center;
    justify-content: center;

    position:fixed;
    width:50%;
    height:100%;
    top:0;
    bottom:0;
    right:0;
    justify-content: center;

    z-index: -1;
}

canvas {
    cursor: all-scroll;
    border-radius: 100%;
}

@media (max-width: 720px) {
    #canvas-holder {
        display: flex;
        align-items: center;
        justify-content: center;

        position:fixed;
        width:100%;
        height:100%;
        top:0;
        bottom:0;
        right:0;
        left: 0;
        justify-content: center;

        z-index: -1;
    }
}