:root {
    --primary: #4a6fa5;
    --secondary: #166088;
    --accent: #4fc3f7;
    --light: #ffffff;
    --dark: #2c3e50;
    --success: #4CAF50;
    --warning: #FFC107;
    --error: #F44336;
    --cell-bg: #c0c0c0;
    --cell-border: #808080;
    --cell-shadow: inset -2px -2px 2px rgba(0, 0, 0, 0.2), inset 2px 2px 2px rgba(255, 255, 255, 0.8);
    --cell-active: inset -1px -1px 1px rgba(0, 0, 0, 0.2), inset 1px 1px 1px rgba(255, 255, 255, 0.8);
    --transition: all 0.2s ease;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Arial', sans-serif;
}

body {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--light);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
    overflow-x: hidden;
}

.game-container {
    max-width: 95vw;
    width: 100%;
    margin: 0 auto;
    text-align: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 15px;
    padding: 20px;
    backdrop-filter: blur(5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    display: flex;
    flex-direction: column;
    align-items: center;
}

h1 {
    margin: 10px 0 20px;
    font-size: 2.5rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    color: var(--light);
}

.game-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 20px;
    background: rgba(0, 0, 0, 0.2);
    padding: 15px;
    border-radius: 10px;
    width: 100%;
    max-width: 600px;
}

.info-item {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--light);
}

.controls {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 20px;
    flex-wrap: wrap;
    width: 100%;
    max-width: 600px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
    background: var(--accent);
    color: var(--dark);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.3);
}

.btn:active {
    transform: translateY(0);
}

.difficulty-select {
    padding: 8px 15px;
    border-radius: 5px;
    border: none;
    background: var(--light);
    font-size: 1rem;
}

.game-board-container {
    width: 100%;
    overflow: auto;
    padding: 10px;
    max-width: 95vw;
    display: flex;
    justify-content: center;
}

.game-board {
    display: grid;
    border: 2px solid var(--cell-border);
    background: var(--cell-bg);
    box-shadow: var(--cell-shadow);
    margin: 0 auto;
}

.cell {
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    cursor: pointer;
    user-select: none;
    box-shadow: var(--cell-shadow);
    transition: var(--transition);
    position: relative;
    min-width: 25px;
    min-height: 25px;
}

.cell:hover {
    background: rgba(255, 255, 255, 0.3);
}

.cell.revealed {
    background: var(--light);
    box-shadow: var(--cell-active);
}

.cell.flagged::after {
    content: '🚩';
    position: absolute;
    font-size: 0.9rem;
}

.cell.mine::after {
    content: '💣';
    position: absolute;
    font-size: 0.9rem;
}

.cell.mine.revealed {
    background: var(--error);
}

.cell.number-1 { color: #0000FF; }
.cell.number-2 { color: #008000; }
.cell.number-3 { color: #FF0000; }
.cell.number-4 { color: #000080; }
.cell.number-5 { color: #800000; }
.cell.number-6 { color: #008080; }
.cell.number-7 { color: #000000; }
.cell.number-8 { color: #808080; }

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
}

.modal.show {
    opacity: 1;
    pointer-events: all;
}

.modal-content {
    background: white;
    color: var(--dark);
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    max-width: 400px;
    width: 90%;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    transform: translateY(-50px);
    transition: var(--transition);
}

.modal.show .modal-content {
    transform: translateY(0);
}

.modal h2 {
    margin-bottom: 15px;
    color: var(--primary);
}

.modal p {
    margin-bottom: 20px;
    font-size: 1.1rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

    .game-info {
        flex-direction: column;
        gap: 10px;
    }

    .info-item {
        font-size: 1rem;
    }

    .controls {
        flex-direction: column;
        align-items: center;
    }

    .cell {
        min-width: 20px;
        min-height: 20px;
        font-size: 0.8rem;
    }

    .cell.flagged::after, .cell.mine::after {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.8rem;
    }

    .game-container {
        padding: 15px;
    }

    .cell {
        min-width: 18px;
        min-height: 18px;
        font-size: 0.7rem;
    }

    .cell.flagged::after, .cell.mine::after {
        font-size: 0.7rem;
    }

    .game-board-container {
        padding: 5px;
    }
}

/* 针对困难模式的特殊处理 */
.difficulty-hard .cell {
    min-width: 18px;
    min-height: 18px;
    font-size: 0.7rem;
}

.difficulty-hard .cell.flagged::after,
.difficulty-hard .cell.mine::after {
    font-size: 0.7rem;
}