body {
    margin: 0;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #333;
    position: relative;
}

canvas {
    background-color: #000;
    border: 2px solid #fff;
    display: block;
    width: 800px;
    height: 600px;
    cursor: pointer;
}