body,
html {
    position: absolute;
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
}
canvas {
    width: 100vw;
    height: 100vw;
    max-height: 100vh;
    max-width: 100vh;
    margin: auto;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}