/* 全局样式 - 卡通可爱风格（完全复用原样式） */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: "Microsoft YaHei", 幼圆, sans-serif;
        }

        body {
            background-color: #f9f5e8;
            color: #333;
            background-image: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M11 18c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm48 25c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm-43-7c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm63 31c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM34 90c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm56-76c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM12 86c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm28-65c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm23-11c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-6 60c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm29 22c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zM32 63c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm57-13c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-9-21c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM60 91c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM35 41c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM12 60c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2z' fill='%2386e57f' fill-opacity='0.2' fill-rule='evenodd'/%3E%3C/svg%3E");
        }

        header {
            background: linear-gradient(120deg, #86e57f 0%, #b8f0b3 100%);
            padding: 20px;
            text-align: center;
            border-radius: 0 0 20px 20px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }

        h1 {
            color: #fff;
            font-size: 2.2rem;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
            margin-bottom: 10px;
        }

        .subtitle {
            color: #fff;
            font-size: 1.1rem;
            font-weight: normal;
        }

        .nav {
            display: flex;
            justify-content: center;
            gap: 15px;
            margin: 20px 0;
            flex-wrap: wrap;
        }

        .nav-btn {
            background: #66cc66;
            color: white;
            border: none;
            padding: 12px 24px;
            border-radius: 50px;
            font-size: 1rem;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 8px rgba(102,204,102,0.3);
        }

        .nav-btn:hover {
            background: #4ebb4e;
            transform: translateY(-3px);
            box-shadow: 0 6px 12px rgba(102,204,102,0.5);
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px;
        }

        .module {
            background: white;
            border-radius: 20px;
            padding: 25px;
            margin-bottom: 30px;
            box-shadow: 0 6px 15px rgba(0,0,0,0.08);
            border: 2px solid #d6f5d4;
        }

        .module-title {
            color: #4ebb4e;
            font-size: 1.8rem;
            margin-bottom: 20px;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .module-title::before {
            content: "✨";
            font-size: 1.5rem;
        }

        .section {
            margin-bottom: 25px;
        }

        .section h3 {
            color: #66cc66;
            font-size: 1.4rem;
            margin: 15px 0 10px;
            border-left: 5px solid #66cc66;
            padding-left: 10px;
        }

        .section p {
            line-height: 1.8;
            font-size: 1.05rem;
            margin-bottom: 10px;
        }

        .section ul {
            margin-left: 30px;
            line-height: 1.8;
        }

        .section li {
            margin-bottom: 8px;
        }

        .fmt-table {
            width: 100%;
            border-collapse: collapse;
            margin: 20px 0;
            border-radius: 10px;
            overflow: hidden;
        }

        .fmt-table th, .fmt-table td {
            padding: 12px;
            text-align: center;
            border: 2px solid #d6f5d4;
        }

        .fmt-table th {
            background: #e8f9e8;
            color: #4ebb4e;
        }

        .fmt-table tr:nth-child(even) {
            background: #f8fef8;
        }

        .code-block {
            background: #f8f8f8;
            border-radius: 10px;
            padding: 15px;
            margin: 15px 0;
            font-family: "Consolas", "Monaco", monospace;
            font-size: 1rem;
            line-height: 1.6;
            overflow-x: auto;
            border: 2px solid #d6f5d4;
            tab-size: 4;
            white-space: pre;
        }

        .example {
            background: #f8fef8;
            border-radius: 15px;
            padding: 20px;
            margin: 20px 0;
            border-left: 8px solid #66cc66;
        }

        .example h4 {
            color: #4ebb4e;
            font-size: 1.2rem;
            margin-bottom: 10px;
        }

        .show-answer-btn {
            margin-top: 10px;
            width: auto;
            padding: 8px 20px;
            display: inline-block;
        }

        .answer {
            margin-top: 15px;
            padding: 10px;
            background: #e8f9e8;
            border-radius: 8px;
            display: none; /* 默认隐藏结果/解析 */
        }

        .pk-container {
            display: flex;
            gap: 20px;
            flex-wrap: wrap;
        }

        .player-panel {
            flex: 1;
            min-width: 400px;
            background: linear-gradient(180deg, #fff 0%, #f8fef8 100%);
            border-radius: 20px;
            padding: 25px;
            box-shadow: 0 8px 20px rgba(0,0,0,0.1);
            border: 3px solid #86e57f;
        }

        .player1 {
            border-color: #ff9a9e;
        }

        .player2 {
            border-color: #86e57f;
        }

        .player-title {
            text-align: center;
            font-size: 1.5rem;
            color: white;
            padding: 12px;
            border-radius: 15px;
            margin-bottom: 20px;
        }

        .player1 .player-title {
            background: #ff9a9e;
        }

        .player2 .player-title {
            background: #86e57f;
        }

        .progress {
            background: #f0f0f0;
            border-radius: 50px;
            height: 20px;
            margin: 15px 0;
            overflow: hidden;
        }

        .progress-bar {
            height: 100%;
            border-radius: 50px;
            transition: width 0.5s ease;
        }

        .player1 .progress-bar {
            background: #ff9a9e;
        }

        .player2 .progress-bar {
            background: #86e57f;
        }

        .level-info {
            text-align: center;
            font-size: 1.2rem;
            margin: 15px 0;
            color: #666;
        }

        .timer {
            text-align: center;
            font-size: 1.3rem;
            font-weight: bold;
            margin: 10px 0;
            color: #4ebb4e;
        }

        .question-area {
            background: #f8f8f8;
            border-radius: 15px;
            padding: 20px;
            margin: 20px 0;
            min-height: 120px;
            display: flex;
            align-items: center;
            justify-content: center;
            border: 2px dashed #d6f5d4;
        }

        .options {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 15px;
            margin: 20px 0;
        }

        .option-btn {
            background: #fff;
            border: 2px solid #d6f5d4;
            border-radius: 10px;
            padding: 12px;
            font-size: 1rem;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .option-btn:hover {
            background: #f8fef8;
            border-color: #66cc66;
        }

        .option-btn.correct {
            background: #d4edda;
            border-color: #28a745;
            color: #155724;
        }

        .option-btn.wrong {
            background: #f8d7da;
            border-color: #dc3545;
            color: #721c24;
        }

        .control-btn {
            display: block;
            width: 100%;
            padding: 12px;
            margin: 10px 0;
            border: none;
            border-radius: 10px;
            font-size: 1rem;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .start-btn {
            background: #66cc66;
            color: white;
        }

        .start-btn:hover {
            background: #4ebb4e;
        }

        .next-btn {
            background: #ff9a9e;
            color: white;
            display: none;
        }

        .next-btn:hover {
            background: #ff7e95;
        }

        .result {
            text-align: center;
            font-size: 1.5rem;
            font-weight: bold;
            margin: 20px 0;
            padding: 15px;
            border-radius: 15px;
            display: none;
        }

        .success {
            background: #d4edda;
            color: #155724;
        }

        .fail {
            background: #f8d7da;
            color: #721c24;
        }

        footer {
            max-width: 1200px;
            margin: 0 auto 30px;
            padding: 20px;
            text-align: center;
            border-top: 2px solid #d6f5d4;
            background: #f8fef8;
            border-radius: 15px;
        }

        .footer-links {
            margin-bottom: 15px;
            display: flex;
            justify-content: center;
            gap: 25px;
            flex-wrap: wrap;
        }

        .footer-links a {
            color: #4ebb4e;
            text-decoration: none;
            font-size: 1rem;
            transition: all 0.3s ease;
        }

        .footer-links a:hover {
            color: #ff9a9e;
            text-decoration: underline;
        }

        .copyright {
            color: #666;
            font-size: 0.9rem;
        }

        @media (max-width: 900px) {
            .pk-container {
                flex-direction: column;
            }
            .player-panel {
                min-width: 100%;
            }
            .options {
                grid-template-columns: 1fr;
            }
        }

        @media (max-width: 600px) {
            h1 {
                font-size: 1.8rem;
            }
            .module-title {
                font-size: 1.5rem;
            }
            .container {
                padding: 10px;
            }
            .module {
                padding: 15px;
            }
            .footer-links {
                gap: 15px;
            }
        }