body {
    margin: 0;
    padding: 0;
    background-color: #1a1a1a;
    overflow: hidden;
    color: white;
    font-family: 'Segoe UI', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

canvas {
    box-shadow: 0 0 20px rgba(0, 255, 255, 0.2);
    border: 2px solid #333;
    background-color: #0d0d0d;
    display: block; /* Ngăn chặn scrollbar ẩn */
}

#ui {
    position: absolute;
    top: 20px;
    left: 20px;
    pointer-events: none; /* Để chuột click xuyên qua UI vào game */
    z-index: 10;
}

.game-title {
    margin: 0;
    text-shadow: 0 0 10px cyan;
    font-size: 24px;
    letter-spacing: 2px;
}

#score {
    font-size: 20px;
    font-weight: bold;
    margin-top: 5px;
}

.instruction {
    font-size: 14px;
    color: #888;
    margin-top: 5px;
    line-height: 1.4;
}