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

body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.container {
    background-color: white;
    border-radius: 15px;
    padding: 20px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    text-align: center;
    max-width: 100%;
}

h1 {
    color: #333;
    margin-bottom: 20px;
    font-size: 2rem;
}

.game-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    background-color: #f9f9f9;
    padding: 15px;
    border-radius: 10px;
    border: 1px solid #ddd;
}

.timer, .mines-left {
    font-size: 1.2rem;
    font-weight: bold;
    color: #555;
    background-color: #000;
    color: #f00;
    padding: 8px 15px;
    border-radius: 5px;
    min-width: 100px;
}

.face-btn {
    font-size: 1.5rem;
    width: 50px;
    height: 50px;
    border: 2px solid #333;
    border-radius: 50%;
    cursor: pointer;
    background-color: #ddd;
    transition: transform 0.1s;
}

.face-btn:hover {
    background-color: #ccc;
}

.face-btn:active {
    transform: scale(0.95);
}

.difficulty {
    margin-bottom: 20px;
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
}

.difficulty-btn {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.3s;
}

.difficulty-btn:hover {
    background-color: #45a049;
}

.difficulty-btn.active {
    background-color: #2196F3;
    font-weight: bold;
}

.game-board {
    display: inline-grid;
    gap: 1px;
    background-color: #333;
    border: 3px solid #333;
    border-radius: 5px;
    margin-bottom: 20px;
    padding: 5px;
}

.cell {
    width: 30px;
    height: 30px;
    background-color: #ddd;
    border: 2px solid;
    border-color: #fff #888 #888 #fff;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    font-size: 1rem;
    transition: all 0.1s;
}

.cell:hover {
    background-color: #ccc;
}

.cell.revealed {
    background-color: #eee;
    border: 1px solid #999;
    cursor: default;
}

.cell.flagged {
    background-color: #ddd;
    font-size: 1.2rem;
}

.cell.mine {
    background-color: #f00;
}

.cell.exploded {
    background-color: #ff0;
}

/* 数字颜色 */
.cell.number-1 { color: #0000ff; }
.cell.number-2 { color: #008200; }
.cell.number-3 { color: #ff0000; }
.cell.number-4 { color: #000084; }
.cell.number-5 { color: #840000; }
.cell.number-6 { color: #008284; }
.cell.number-7 { color: #000000; }
.cell.number-8 { color: #848484; }

.instructions {
    background-color: #f9f9f9;
    padding: 15px;
    border-radius: 10px;
    border: 1px solid #ddd;
}

.instructions h3 {
    color: #333;
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.instructions p {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.4;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    .cell {
        width: 25px;
        height: 25px;
        font-size: 0.8rem;
    }
    
    .timer, .mines-left {
        font-size: 1rem;
        min-width: 80px;
        padding: 6px 12px;
    }
    
    .face-btn {
        font-size: 1.2rem;
        width: 40px;
        height: 40px;
    }
    
    .difficulty-btn {
        padding: 8px 12px;
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .cell {
        width: 20px;
        height: 20px;
        font-size: 0.7rem;
    }
    
    .difficulty {
        flex-direction: column;
        align-items: center;
    }
    
    .difficulty-btn {
        width: 100%;
        max-width: 200px;
    }
}