body {
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #2c3e50;
    font-family: 'Arial', sans-serif;
}

.game-container {
    text-align: center;
    background-color: #34495e;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,0,0,0.3);
}

h1 {
    color: #ecf0f1;
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 2px;
}

#gameCanvas {
    background-color: #2c3e50;
    border: 4px solid #95a5a6;
    border-radius: 5px;
}

.game-stats {
    color: #ecf0f1;
    font-size: 1.2em;
    margin: 10px 0;
}

.game-controls {
    margin-top: 20px;
}

#startBtn {
    background-color: #27ae60;
    color: white;
    border: none;
    padding: 10px 20px;
    font-size: 1.1em;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#startBtn:hover {
    background-color: #219a52;
}

.instructions {
    color: #bdc3c7;
    font-size: 0.9em;
    margin-top: 10px;
}

.mobile-controls {
    display: none;
    flex-direction: column;
    align-items: center;
    margin: 20px 0;
    gap: 10px;
}

.horizontal-controls {
    display: flex;
    gap: 40px;
}

.mobile-controls button {
    width: 60px;
    height: 60px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

.mobile-controls button:active {
    background-color: #2980b9;
}

/* 在移动设备上显示控制按钮 */
@media (max-width: 768px) {
    .mobile-controls {
        display: flex;
    }
    
    .game-container {
        padding: 10px;
    }
    
    #gameCanvas {
        width: 300px;
        height: 300px;
    }
    
    .instructions {
        font-size: 0.8em;
    }
}