* {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }

    body {
        font-family: 'Arial', 'Microsoft JhengHei', sans-serif;
        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        display: flex;
        justify-content: center;
        align-items: flex-start;
        height: 100vh;
        padding: 5px;
        margin: 0;
    }

    #game-container {
        background: white;
        border-radius: 15px;
        box-shadow: 0 10px 50px rgba(0,0,0,0.3);
        padding: 10px;
        max-width: 900px;
        width: 100%;
        overflow: hidden;
        max-height: 100vh;
        display: flex;
        flex-direction: column;
    }

    h1 {
        text-align: center;
        color: #333;
        margin: 5px 0;
        font-size: 1.3em;
    }

    #gameCanvas {
        display: block;
        margin: 0 auto;
        background: linear-gradient(to bottom, #87CEEB 0%, #E0F6FF 100%);
        border: 3px solid #333;
        border-radius: 10px;
        cursor: crosshair;
    }

    #controls {
        margin-top: 8px;
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        align-items: center;
        gap: 8px;
    }

    button {
        padding: 8px 16px;
        font-size: 14px;
        font-weight: bold;
        border: none;
        border-radius: 8px;
        cursor: pointer;
        transition: all 0.3s;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    }

    #startGame {
        background: #4CAF50;
        color: white;
    }

    #startGame:hover {
        background: #45a049;
        transform: translateY(-2px);
        box-shadow: 0 6px 8px rgba(0,0,0,0.2);
    }

    #resetGame {
        background: #f44336;
        color: white;
    }

    #resetGame:hover {
        background: #da190b;
        transform: translateY(-2px);
        box-shadow: 0 6px 8px rgba(0,0,0,0.2);
    }

    #score {
        font-size: 14px;
        font-weight: bold;
        color: #333;
        padding: 6px 12px;
        background: #FFD700;
        border-radius: 8px;
    }

    #difficulty {
        display: flex;
        align-items: center;
        gap: 10px;
    }

    #difficulty label {
        font-weight: bold;
        color: #333;
    }

    #difficultySelect {
        padding: 8px 16px;
        font-size: 16px;
        border: 2px solid #667eea;
        border-radius: 8px;
        cursor: pointer;
        background: white;
    }

    #instructions {
        margin-top: 8px;
        padding: 8px;
        background: #f0f0f0;
        border-radius: 8px;
        text-align: center;
        display: none;
    }

    #instructions p {
        margin: 5px 0;
        color: #555;
    }

    .game-info {
        display: flex;
        justify-content: space-around;
        margin-top: 8px;
        padding: 6px;
        background: #f9f9f9;
        border-radius: 8px;
    }

    .info-item {
        text-align: center;
    }

    .info-label {
        font-size: 12px;
        color: #666;
        margin-bottom: 5px;
    }

    .info-value {
        font-size: 16px;
        font-weight: bold;
        color: #333;
    }