body {
    margin: 0;
    padding: 0;
    background-color: #2d2d2d;
    overflow: hidden;
    touch-action: none;
    font-family: Arial, sans-serif;
}

canvas {
    display: block;
    margin: 0 auto;
}

/* スタート画面用のオーバーレイ */
#start-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    cursor: pointer;
}

#start-text {
    color: white;
    font-size: 24px;
    text-align: center;
    border: 2px solid white;
    padding: 20px;
    border-radius: 10px;
    background-color: rgba(0, 0, 0, 0.5);
}