html,
body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    margin: 0;
    padding: 0;
    background: #231F20;
    display: flex;
    justify-content: center;
    align-items: center;
}

body.mobile {
    text-align: left;
}

body.mobile #tuanjie-canvas {
    position: fixed;
}