:root {
            --primary: #4285f4;
            --light-bg: #f5f7fa;
            --card-bg: #ffffff;
            --text-primary: #202124;
            --text-secondary: #5f6368;
            --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
            --shadow-hover: 0 6px 25px rgba(0, 0, 0, 0.12);
            --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        body { 
            font-family: 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', sans-serif;
            background-color: var(--light-bg);
            color: var(--text-primary);
            line-height: 1.6;

            min-height: 100vh;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px 15px;
            width: 100%;
        }

        .app-header {
            text-align: center;
            margin-bottom: 30px;
            padding: 20px 0;
            border-bottom: 1px solid #eee;
        }

        .app-logo {
            font-size: 2rem;
            font-weight: 700;
            background: linear-gradient(135deg, #4285f4, #34a853, #fbbc05, #ea4335);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            margin-bottom: 15px;
        }

        .countdown {
            background-color: var(--card-bg);
            display: inline-block;
            padding: 8px 20px;
            border-radius: 30px;
            box-shadow: var(--shadow);
            font-size: 1.1rem;
            color: var(--text-primary);
            margin-bottom: 20px;
        }

        .countdown span {
            color: var(--primary);
            font-weight: 600;
            font-size: 1.2rem;
        }

        /* AI问答区域样式 - 替换原搜索框 */
        .ai-qa-container {
            max-width: 800px;
            margin: 0 auto 30px;
            display: flex;
            flex-direction: column;
            gap: 15px;
        }

        .qa-input-group {
            display: flex;
            gap: 10px;
        }

        #aiQuestionInput {
            flex: 1;
            padding: 14px 16px;
            font-size: 16px;
            border: 1px solid #ddd;
            border-radius: 8px;
            outline: none;
            resize: none;
            min-height: 60px;
        }

        #aiQuestionInput:focus {
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(66, 133, 244, 0.2);
        }

        .qa-btn {
            padding: 14px 24px;
            font-size: 16px;
            font-weight: 500;
            cursor: pointer;
            border: none;
            border-radius: 8px;
            background: var(--primary);
            color: white;
            transition: var(--transition);
            white-space: nowrap;
        }

        .qa-btn:hover {
            background: #3367d6;
            transform: translateY(-2px);
        }

        .qa-btn:disabled {
            background: #a0b8e0;
            cursor: not-allowed;
            transform: none;
        }

        /* AI回答展示区域 - 初始完全隐藏（不占位置），点击后弹出 */
        .ai-answer-container {
            background: var(--card-bg);
            padding: 20px;
            border-radius: 12px;
            box-shadow: var(--shadow);
            min-height: 120px;
            display: none; /* 初始完全隐藏，不占任何空间 */
            flex-direction: column;
            transition: var(--transition);
            animation: fadeIn 0.3s ease-out; /* 弹出动画 */
        }

        /* 点击AI解答后显示容器 */
        .ai-answer-container.active {
            display: flex; /* 显示为flex布局 */
        }

        /* 弹出动画 */
        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: translateY(10px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .answer-header {
            display: flex;
            align-items: center;
            gap: 8px;
            margin-bottom: 12px;
            color: var(--primary);
            font-weight: 500;
        }

        .answer-loading {
            text-align: center;
            padding: 30px;
            color: var(--text-secondary);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }

        .answer-content {
            line-height: 1.8;
            color: var(--text-primary);
            white-space: pre-wrap;
            word-break: break-all;
            padding: 10px 0;
        }

        .answer-error {
            color: #ea4335;
            text-align: center;
            padding: 30px;
        }

        .section {
            background: var(--card-bg);
            padding: 25px;
            border-radius: 12px;
            box-shadow: var(--shadow);
            margin-bottom: 30px;
            transition: var(--transition);
        }

        .section:hover {
            box-shadow: var(--shadow-hover);
        }

        .section-title {
            font-size: 1.5rem;
            font-weight: 600;
            color: var(--primary);
            margin-bottom: 20px;
            padding-bottom: 10px;
            border-bottom: 1px solid #eee;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .refresh-btn {
            padding: 6px 12px;
            font-size: 0.9rem;
            background: var(--light-bg);
            color: var(--text-primary);
            border: none;
            border-radius: 6px;
            cursor: pointer;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 5px;
        }

        .refresh-btn:hover {
            background: rgba(66, 133, 244, 0.1);
            color: var(--primary);
        }

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

        .site-category {
            margin-bottom: 25px;
        }

        .category-title {
            font-size: 1.1rem;
            color: var(--text-primary);
            margin-bottom: 12px;
            font-weight: 500;
        }

        .nav-link {
            display: block;
            padding: 12px 15px;
            border-radius: 8px;
            background-color: var(--light-bg);
            color: var(--text-primary);
            text-decoration: none;
            transition: var(--transition);
            text-align: center;
        }

        .nav-link:hover {
            background-color: rgba(66, 133, 244, 0.1);
            color: var(--primary);
            transform: translateY(-2px);
        }

        /* 新闻快讯样式 */
        .news-container {
            display: flex;
            flex-direction: column;
            gap: 15px;
            max-height: 400px;
            overflow-y: auto;
            padding-right: 10px;
        }

        .news-item {
            padding: 15px;
            border-radius: 8px;
            background-color: var(--light-bg);
            transition: var(--transition);
            border-left: 3px solid var(--primary);
            display: flex;
            gap: 15px;
        }

        .news-img-container {
            width: 120px;
            height: 80px;
            flex-shrink: 0;
            border-radius: 6px;
            overflow: hidden;
            background-color: #eee;
            display: flex;
            align-items: center;
            justify-content: center;
            position: relative;
        }

        .news-img {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            object-fit: cover;
            object-position: center center;
            transition: var(--transition);
        }

        .news-img:hover {
            transform: scale(1.05);
        }

        .news-no-img {
            font-size: 0.8rem;
            color: var(--text-secondary);
            text-align: center;
            padding: 5px;
            line-height: 1.2;
            z-index: 1;
        }

        .news-content-wrapper {
            flex: 1;
            display: flex;
            flex-direction: column;
        }

        .news-date {
            font-size: 0.85rem;
            color: var(--text-secondary);
            margin-bottom: 5px;
        }

        .news-title {
            font-size: 1.1rem;
            font-weight: 500;
            margin-bottom: 8px;
            color: var(--text-primary);
            line-height: 1.4;
        }

        .news-content {
            font-size: 0.95rem;
            color: var(--text-secondary);
            margin-bottom: 10px;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
            flex: 1;
        }

        .news-link {
            font-size: 0.9rem;
            color: var(--primary);
            text-decoration: none;
            font-weight: 500;
            align-self: flex-start;
        }

        .news-link:hover {
            text-decoration: underline;
        }

        .news-loading {
            text-align: center;
            padding: 30px;
            color: var(--text-secondary);
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 10px;
        }

        .news-error {
            text-align: center;
            padding: 30px;
            color: #ea4335;
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 15px;
        }

        .error-retry-btn {
            padding: 8px 20px;
            font-size: 0.95rem;
            background: var(--primary);
            color: white;
            border: none;
            border-radius: 6px;
            cursor: pointer;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 5px;
        }

        .error-retry-btn:hover {
            background: #3367d6;
            transform: translateY(-2px);
        }

        .error-desc {
            font-size: 0.9rem;
            color: var(--text-secondary);
            max-width: 300px;
            line-height: 1.5;
        }

        .footer {
            text-align: center;
            margin-top: 40px;
            color: var(--text-secondary);
            font-size: 13px;
            padding: 15px 0;
            border-top: 1px solid #eee;
        }

        /* 加载动画 */
        .loading-spinner {
            width: 24px;
            height: 24px;
            border: 3px solid rgba(66, 133, 244, 0.2);
            border-top: 3px solid var(--primary);
            border-radius: 50%;
            animation: spin 1s linear infinite;
        }

        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }

        /* 响应式调整 */
        @media (max-width: 768px) {
            .app-logo {
                font-size: 1.6rem;
            }

            .qa-input-group {
                flex-direction: column;
            }

            .tools-grid, .sites-grid {
                grid-template-columns: 1fr 1fr;
            }

            .section-title {
                font-size: 1.3rem;
                flex-direction: column;
                align-items: flex-start;
                gap: 10px;
            }

            .news-item {
                flex-direction: column;
                gap: 10px;
            }

            .news-img-container {
                width: 100%;
                height: 150px;
            }

            .ai-answer-container.active {
                padding: 15px;
            }
        }

        @media (max-width: 480px) {
            .tools-grid, .sites-grid {
                grid-template-columns: 1fr;
            }

            .section {
                padding: 18px;
            }

            .news-container {
                max-height: 300px;
            }

            .news-img-container {
                height: 120px;
            }
        }