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

        body {
            font-family: 'Microsoft YaHei', 'SF Pro Display', -apple-system, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            color: #2c3e50;
            padding: 20px;
            overflow-x: hidden;
        }

        .game-container {
            max-width: 900px;
            margin: 0 auto;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(20px);
            border-radius: 24px;
            padding: 30px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
        }

        h1 {
            text-align: center;
            font-size: 2.8rem;
            color: #2c3e50;
            margin-bottom: 30px;
            font-weight: 700;
            text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
        }

        .game-stats {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
            gap: 15px;
            margin-bottom: 25px;
        }

        .stat-item {
            background: linear-gradient(135deg, #FF6B6B, #FF8E85);
            color: white;
            padding: 15px;
            border-radius: 16px;
            text-align: center;
            box-shadow: 0 8px 25px rgba(255, 107, 107, 0.3);
            transition: transform 0.3s ease;
        }

        .stat-item:hover {
            transform: translateY(-2px);
        }

        .stat-label {
            font-size: 0.85rem;
            font-weight: 600;
            opacity: 0.9;
            margin-bottom: 5px;
        }

        .stat-value {
            font-size: 1.4rem;
            font-weight: 700;
        }

        .difficulty-selector {
            margin-bottom: 25px;
            text-align: center;
            background: rgba(255, 255, 255, 0.8);
            padding: 20px;
            border-radius: 16px;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
        }

        .difficulty-selector h3 {
            color: #2c3e50;
            margin-bottom: 15px;
            font-size: 1.2rem;
        }

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

        .difficulty-btn {
            padding: 10px 20px;
            border: 2px solid #e2e8f0;
            border-radius: 25px;
            background: white;
            color: #2c3e50;
            cursor: pointer;
            transition: all 0.3s ease;
            font-weight: 600;
            font-size: 0.9rem;
        }

        .difficulty-btn:hover {
            background: #f8fafc;
            transform: translateY(-2px);
        }

        .difficulty-btn.active {
            background: linear-gradient(135deg, #FF6B6B, #FF8E85);
            color: white;
            border-color: #FF6B6B;
        }

        .game-controls {
            display: flex;
            gap: 15px;
            margin-bottom: 30px;
            justify-content: center;
            flex-wrap: wrap;
        }

        .btn {
            padding: 12px 24px;
            border: none;
            border-radius: 50px;
            background: linear-gradient(135deg, #667eea, #764ba2);
            color: white;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            font-size: 0.9rem;
            box-shadow: 0 6px 20px rgba(102, 126, 234, 0.3);
        }

        .btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
        }

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

        .btn.secondary {
            background: linear-gradient(135deg, #4ECDC4, #44A08D);
            box-shadow: 0 6px 20px rgba(78, 205, 196, 0.3);
        }

        .btn.secondary:hover {
            box-shadow: 0 8px 25px rgba(78, 205, 196, 0.4);
        }

        .btn.success {
            background: linear-gradient(135deg, #4CAF50, #45a049);
            box-shadow: 0 6px 20px rgba(76, 175, 80, 0.3);
        }

        .btn.success:hover {
            box-shadow: 0 8px 25px rgba(76, 175, 80, 0.4);
        }

        .game-board-container {
            display: flex;
            justify-content: center;
            margin-bottom: 30px;
        }

        .game-board {
            background: #34495e;
            padding: 15px;
            border-radius: 16px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
            display: grid;
            gap: 8px;
            max-width: 600px;
            width: 100%;
        }

        .tile {
            aspect-ratio: 1;
            background: linear-gradient(135deg, #ecf0f1, #bdc3c7);
            border-radius: 12px;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
            position: relative;
            overflow: hidden;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 2rem;
            font-weight: 700;
            color: #2c3e50;
        }

        .tile:hover {
            transform: scale(1.05);
            box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
        }

        .tile.selected {
            background: linear-gradient(135deg, #3498db, #2980b9);
            color: white;
            transform: scale(1.1);
            box-shadow: 0 8px 20px rgba(52, 152, 219, 0.4);
        }

        .tile.matched {
            background: linear-gradient(135deg, #27ae60, #2ecc71);
            color: white;
            animation: matchedPulse 0.6s ease;
        }

        .tile.wrong {
            background: linear-gradient(135deg, #e74c3c, #c0392b);
            color: white;
            animation: wrongShake 0.5s ease;
        }

        .tile.hint {
            animation: hintGlow 1s ease infinite;
        }

        @keyframes matchedPulse {
            0%, 100% { transform: scale(1); }
            50% { transform: scale(1.15); }
        }

        @keyframes wrongShake {
            0%, 100% { transform: translateX(0); }
            25% { transform: translateX(-5px); }
            75% { transform: translateX(5px); }
        }

        @keyframes hintGlow {
            0%, 100% { box-shadow: 0 0 0 rgba(255, 193, 7, 0.7); }
            50% { box-shadow: 0 0 20px rgba(255, 193, 7, 0.9); }
        }

        .progress-section {
            background: rgba(255, 255, 255, 0.8);
            padding: 20px;
            border-radius: 16px;
            margin-bottom: 20px;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
        }

        .progress-bar {
            width: 100%;
            height: 12px;
            background: #e2e8f0;
            border-radius: 6px;
            overflow: hidden;
            margin-bottom: 10px;
        }

        .progress-fill {
            height: 100%;
            background: linear-gradient(90deg, #FF6B6B, #4ECDC4);
            border-radius: 6px;
            transition: width 0.3s ease;
            width: 0%;
        }

        .progress-text {
            text-align: center;
            font-weight: 600;
            color: #2c3e50;
        }

        .game-complete-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.8);
            display: none;
            align-items: center;
            justify-content: center;
            z-index: 1000;
        }

        .complete-content {
            background: white;
            padding: 40px;
            border-radius: 20px;
            text-align: center;
            max-width: 400px;
            margin: 20px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
        }

        .complete-content h2 {
            color: #27ae60;
            margin-bottom: 20px;
            font-size: 2rem;
        }

        .complete-stats {
            margin-bottom: 25px;
        }

        .complete-stats p {
            margin-bottom: 10px;
            font-size: 1.1rem;
            color: #2c3e50;
        }

        .celebration {
            font-size: 3rem;
            margin-bottom: 20px;
            animation: bounce 2s infinite;
        }

        @keyframes bounce {
            0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
            40% { transform: translateY(-10px); }
            60% { transform: translateY(-5px); }
        }

        .instructions {
            background: rgba(255, 255, 255, 0.8);
            padding: 25px;
            border-radius: 16px;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
        }

        .instructions h3 {
            color: #2c3e50;
            margin-bottom: 20px;
            font-size: 1.3rem;
            text-align: center;
        }

        .instruction-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 15px;
        }

        .instruction-item {
            background: white;
            padding: 15px;
            border-radius: 12px;
            box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
            display: flex;
            align-items: center;
            gap: 15px;
        }

        .instruction-icon {
            width: 40px;
            height: 40px;
            background: linear-gradient(135deg, #FF6B6B, #FF8E85);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            flex-shrink: 0;
        }

        .instruction-text {
            flex: 1;
        }

        .instruction-text h4 {
            color: #2c3e50;
            margin-bottom: 5px;
            font-size: 1rem;
        }

        .instruction-text p {
            color: #7f8c8d;
            font-size: 0.85rem;
            line-height: 1.4;
        }

        @media (max-width: 768px) {
            .game-container {
                padding: 20px;
                margin: 10px;
            }

            h1 {
                font-size: 2.2rem;
            }

            .game-stats {
                grid-template-columns: repeat(2, 1fr);
                gap: 10px;
            }

            .difficulty-buttons, .game-controls {
                flex-direction: column;
                align-items: center;
            }

            .btn, .difficulty-btn {
                width: 100%;
                max-width: 200px;
            }

            .instruction-grid {
                grid-template-columns: 1fr;
            }

            .complete-content {
                padding: 30px 20px;
            }
        }

        @media (max-width: 480px) {
            .game-stats {
                grid-template-columns: 1fr;
            }

            .tile {
                font-size: 1.5rem;
            }
        }