body {
    margin: 0;
    padding: 0;
    height: 100vh;
}
audio {
    position: absolute;
    top: 40%;
    left: 50%;
    transform: translate(-50%, -50%);
}
#canvas {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: #000;
}