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

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            user-select: none;
        }

        .container {
            width: 100%;
            max-width: 400px;
            height: 90vh;
            max-height: 700px;
            background: white;
            border-radius: 20px;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
            overflow: hidden;
            position: relative;
        }

        /* 开始界面 */
        .start-screen {
            height: 100%;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            padding: 40px 30px;
            background: linear-gradient(135deg, #FFE5B4 0%, #FFA500 100%);
        }

        .title {
            font-size: 32px;
            font-weight: bold;
            color: #333;
            margin-bottom: 30px;
            text-align: center;
        }

        .mode-selection {
            text-align: center;
            margin-bottom: 40px;
        }

        .mode-title {
            font-size: 20px;
            font-weight: bold;
            color: #333;
            margin-bottom: 20px;
            display: block;
        }

        .mode-hint {
            font-size: 16px;
            color: #666;
            line-height: 1.6;
            display: block;
            max-width: 300px;
        }

        .start-btn {
            background: linear-gradient(45deg, #4CAF50, #45a049);
            color: white;
            border: none;
            padding: 15px 40px;
            font-size: 18px;
            border-radius: 25px;
            cursor: pointer;
            box-shadow: 0 4px 15px rgba(76, 175, 80, 0.3);
            transition: all 0.3s ease;
        }

        .start-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(76, 175, 80, 0.4);
        }

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

        /* 游戏界面 */
        .game-screen {
            height: 100%;
            display: flex;
            flex-direction: column;
            background: #f5f5f5;
        }

        .game-header {
            background: linear-gradient(45deg, #2196F3, #1976D2);
            color: white;
            padding: 15px 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        }

        .home-btn {
            font-size: 20px;
            cursor: pointer;
            padding: 8px;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.2);
            transition: background 0.3s;
        }

        .home-btn:hover {
            background: rgba(255, 255, 255, 0.3);
        }

        .level-info, .correct-info {
            text-align: center;
        }

        .label {
            font-size: 12px;
            opacity: 0.8;
            display: block;
        }

        .value {
            font-size: 20px;
            font-weight: bold;
            display: block;
            margin-top: 2px;
        }

        /* 输入显示区域 */
        .input-display {
            flex: 1;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 30px 20px;
        }

        .input-box {
            width: 100%;
            max-width: 300px;
            min-height: 80px;
            background: white;
            border: 3px solid #ddd;
            border-radius: 15px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
            font-weight: bold;
            color: #333;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            position: relative;
        }

        .input-placeholder {
            position: absolute;
            color: #999;
            font-size: 16px;
            font-weight: normal;
        }

        .input-text {
            color: #2196F3;
            letter-spacing: 5px;
        }

        /* 重听按钮 */
        .replay-container {
            display: flex;
            justify-content: center;
            padding: 20px;
        }

        .replay-button {
            font-size: 40px;
            cursor: pointer;
            padding: 15px;
            border-radius: 50%;
            background: white;
            border: 3px solid #ddd;
            box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
            transition: all 0.3s ease;
        }

        .replay-button:hover {
            transform: scale(1.1);
            border-color: #2196F3;
        }

        .replay-button.replay-disabled {
            opacity: 0.5;
            cursor: not-allowed;
        }

        .replay-button.replay-disabled:hover {
            transform: none;
            border-color: #ddd;
        }

        /* 数字键盘 */
        .keyboard {
            background: white;
            padding: 20px;
            border-top: 1px solid #eee;
        }

        .keyboard-row {
            display: flex;
            justify-content: space-between;
            margin-bottom: 10px;
        }

        .keyboard-row:last-child {
            margin-bottom: 0;
        }

        .key-btn {
            flex: 1;
            margin: 0 5px;
            height: 60px;
            background: #f8f8f8;
            border: 2px solid #ddd;
            border-radius: 15px;
            font-size: 20px;
            font-weight: bold;
            color: #333;
            cursor: pointer;
            transition: all 0.2s ease;
        }

        .key-btn:hover {
            background: #e3f2fd;
            border-color: #2196F3;
            transform: translateY(-2px);
        }

        .key-btn:active {
            transform: translateY(0);
            background: #bbdefb;
        }

        .key-btn.keyboard-disabled {
            opacity: 0.5;
            cursor: not-allowed;
        }

        .key-btn.keyboard-disabled:hover {
            background: #f8f8f8;
            border-color: #ddd;
            transform: none;
        }

        .key-btn.backspace-btn {
            background: #fff3e0;
            border-color: #ff9800;
            color: #ff9800;
        }

        .key-btn.backspace-btn:hover {
            background: #ffe0b2;
            border-color: #f57c00;
        }

        .key-btn.confirm-btn {
            background: #e8f5e8;
            border-color: #4CAF50;
            color: #4CAF50;
        }

        .key-btn.confirm-btn:hover {
            background: #c8e6c9;
            border-color: #45a049;
        }

        .key-btn.confirm-btn.disabled {
            background: #f5f5f5;
            border-color: #ccc;
            color: #999;
            cursor: not-allowed;
        }

        /* 结果弹窗 */
        .result-popup {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            z-index: 1000;
            animation: popupShow 0.3s ease-out;
        }

        @keyframes popupShow {
            from {
                opacity: 0;
                transform: translate(-50%, -50%) scale(0.8);
            }
            to {
                opacity: 1;
                transform: translate(-50%, -50%) scale(1);
            }
        }

        .popup-content {
            background: white;
            padding: 30px 40px;
            border-radius: 20px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
            text-align: center;
            min-width: 200px;
        }

        .popup-icon {
            font-size: 40px;
            margin-bottom: 10px;
            display: block;
        }

        .popup-text {
            font-size: 18px;
            font-weight: bold;
            display: block;
        }

        .success-popup .popup-icon {
            color: #4CAF50;
        }

        .success-popup .popup-text {
            color: #2e7d32;
        }

        .fail-popup .popup-icon {
            color: #f44336;
        }

        .fail-popup .popup-text {
            color: #c62828;
        }

        /* 升级动画 */
        .level-up-animation {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            z-index: 999;
            font-size: 60px;
            color: #4CAF50;
            font-weight: bold;
            animation: levelUp 2s ease-in-out;
        }

        @keyframes levelUp {
            0% {
                opacity: 0;
                transform: translate(-50%, -50%) scale(0.5);
            }
            50% {
                opacity: 1;
                transform: translate(-50%, -50%) scale(1.2);
            }
            100% {
                opacity: 0;
                transform: translate(-50%, -50%) scale(1.5);
            }
        }

        /* 加载状态 */
        .loading {
            display: flex;
            justify-content: center;
            align-items: center;
            height: 200px;
        }

        .loading-text {
            font-size: 16px;
            color: #666;
        }

        /* 响应式设计 */
        @media (max-width: 480px) {
            .container {
                height: 100vh;
                max-height: none;
                border-radius: 0;
            }
            
            .key-btn {
                height: 50px;
                font-size: 18px;
            }
            
            .title {
                font-size: 28px;
            }
        }