body {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    margin: 0;
    background-color: #222;
    font-family: sans-serif;
    overflow: hidden;
    user-select: none;
}

canvas {
    border: 5px solid #333;
    background-color: #fff;
    box-shadow: 0 0 20px rgba(0,0,0,0.4);
    max-width: 100%;
    height: auto;
    outline: none;
}