body {
    background-color: #f0f0f0;
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

canvas {
    display: block;
    margin: 0;
    padding: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    max-width: 60vw;
    max-height: 40vw;
}

@media (max-width: 768px) {
    canvas {
        width: 90vw;
        height: 90vw;
    }
}