* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
        }
        
        body {
            background-color: #f5f7fa;
            color: #333;
            line-height: 1.6;
            padding: 20px;
            position: relative; /* 为返回顶部按钮定位 */
        }
        
        .container {
            max-width: 1400px;
            margin: 0 auto;
            background-color: white;
            border-radius: 12px;
            box-shadow: 0 5px 25px rgba(0, 0, 0, 0.08);
            overflow: hidden;
        }
        
        header {
            background: linear-gradient(135deg, #1a5fb4 0%, #2980b9 100%);
            color: white;
            padding: 25px 30px;
            text-align: center;
        }
        
        h1 {
            font-size: 28px;
            margin-bottom: 8px;
            letter-spacing: 1px;
        }
        
        .subtitle {
            font-size: 16px;
            opacity: 0.9;
            font-weight: 300;
        }
        
        .search-section {
            padding: 25px 30px;
            background-color: #f8fafc;
            border-bottom: 1px solid #eaeaea;
        }
        
        .search-box {
            display: flex;
            gap: 15px;
            flex-wrap: wrap;
        }
        
        #searchInput {
            flex: 1;
            min-width: 300px;
            padding: 14px 20px;
            border: 2px solid #ddd;
            border-radius: 8px;
            font-size: 16px;
            transition: all 0.3s;
        }
        
        #searchInput:focus {
            outline: none;
            border-color: #2980b9;
            box-shadow: 0 0 0 3px rgba(41, 128, 185, 0.2);
        }
        
        .filter-container {
            display: flex;
            flex-direction: column;
            gap: 20px;
            margin-top: 20px;
        }
        
        .filter-row {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        
        .filter-label {
            font-weight: 600;
            color: #2980b9;
            font-size: 15px;
        }
        
        .filter-buttons {
            display: flex;
            gap: 10px;
            flex-wrap: wrap;
        }
        
        .type-filter-btn, .category-filter-btn {
            padding: 8px 16px;
            background-color: white;
            border: 1px solid #ddd;
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.2s;
            font-size: 14px;
        }
        
        .type-filter-btn:hover, .category-filter-btn:hover {
            background-color: #f0f7ff;
        }
        
        .type-filter-btn.active, .category-filter-btn.active {
            background-color: #2980b9;
            color: white;
            border-color: #2980b9;
        }
        
        .type-filter-btn[data-filter="single"]:hover,
        .type-filter-btn[data-filter="single"].active {
            background-color: #1a5fb4;
            border-color: #1a5fb4;
        }
        
        .type-filter-btn[data-filter="multi"]:hover,
        .type-filter-btn[data-filter="multi"].active {
            background-color: #2e7d32;
            border-color: #2e7d32;
        }
        
        .type-filter-btn[data-filter="judge"]:hover,
        .type-filter-btn[data-filter="judge"].active {
            background-color: #f39c12;
            border-color: #f39c12;
        }
        
        .category-filter-btn[data-category="three-system"]:hover,
        .category-filter-btn[data-category="three-system"].active {
            background-color: #1a5fb4;
            border-color: #1a5fb4;
        }
        
        .category-filter-btn[data-category="law-popularization"]:hover,
        .category-filter-btn[data-category="law-popularization"].active {
            background-color: #8e44ad;
            border-color: #8e44ad;
        }
        
        .category-filter-btn[data-category="civil-code"]:hover,
        .category-filter-btn[data-category="civil-code"].active {
            background-color: #16a085;
            border-color: #16a085;
        }
        
        .category-filter-btn[data-category="enterprise-law"]:hover,
        .category-filter-btn[data-category="enterprise-law"].active {
            background-color: #d35400;
            border-color: #d35400;
        }
        
        .category-filter-btn[data-category="xi-thought"]:hover,
        .category-filter-btn[data-category="xi-thought"].active {
            background-color: #c0392b;
            border-color: #c0392b;
        }
        
        .category-filter-btn[data-category="constitution"]:hover,
        .category-filter-btn[data-category="constitution"].active {
            background-color: #2980b9;
            border-color: #2980b9;
        }
        
        .category-filter-btn[data-category="centralized-law"]:hover,
        .category-filter-btn[data-category="centralized-law"].active {
            background-color: #27ae60;
            border-color: #27ae60;
        }
        
        .category-filter-btn[data-category="administrative-law"]:hover,
        .category-filter-btn[data-category="administrative-law"].active {
            background-color: #34495e;
            border-color: #34495e;
        }
        
        .category-filter-btn[data-category="security-concept"]:hover,
        .category-filter-btn[data-category="security-concept"].active {
            background-color: #7f8c8d;
            border-color: #7f8c8d;
        }
        
        .results-info {
            padding: 15px 30px;
            background-color: #f8fafc;
            border-bottom: 1px solid #eaeaea;
            font-size: 15px;
            color: #555;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .current-filters {
            display: flex;
            gap: 10px;
            flex-wrap: wrap;
        }
        
        .filter-tag {
            padding: 4px 10px;
            background-color: #e8f4fd;
            color: #1a5fb4;
            border-radius: 20px;
            font-size: 13px;
            display: flex;
            align-items: center;
            gap: 5px;
        }
        
        .filter-tag .remove {
            cursor: pointer;
            font-weight: bold;
        }
        
        .questions-container {
            padding: 20px 30px 40px;
        }
        
        .question-card {
            background-color: white;
            border-radius: 10px;
            padding: 22px;
            margin-bottom: 20px;
            box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
            border-left: 4px solid #2980b9;
            transition: transform 0.2s, box-shadow 0.2s;
        }
        
        .question-card:hover {
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
        }
        
        .question-header {
            display: flex;
            justify-content: space-between;
            align-items: flex-start;
            margin-bottom: 15px;
            flex-wrap: wrap;
            gap: 10px;
        }
        
        .question-meta {
            display: flex;
            gap: 10px;
            align-items: center;
            flex-wrap: wrap;
        }
        
        .question-type {
            display: inline-block;
            padding: 4px 12px;
            border-radius: 20px;
            font-size: 13px;
            font-weight: 600;
        }
        
        .question-category {
            display: inline-block;
            padding: 4px 12px;
            border-radius: 20px;
            font-size: 13px;
            background-color: #f1f8ff;
            color: #1a5fb4;
        }
        
        .single-choice {
            background-color: #e8f4fd;
            color: #1a5fb4;
        }
        
        .multi-choice {
            background-color: #f0f7e8;
            color: #2e7d32;
        }
        
        .judgment {
            background-color: #fef5e7;
            color: #f39c12;
        }
        
        .question-number {
            font-weight: bold;
            color: #555;
            font-size: 15px;
        }
        
        .question-text {
            font-size: 17px;
            margin-bottom: 18px;
            line-height: 1.7;
            color: #222;
        }
        
        .options-list {
            margin-left: 10px;
            margin-bottom: 20px;
        }
        
        .option-item {
            padding: 8px 0;
            padding-left: 10px;
            border-left: 3px solid transparent;
            transition: all 0.2s;
        }
        
        .option-item.correct {
            border-left-color: #27ae60;
            background-color: #f0f9f0;
        }
        
        .answer-section {
            background-color: #f8fafc;
            padding: 15px;
            border-radius: 8px;
            margin-top: 15px;
        }
        
        .answer-title {
            font-weight: 600;
            color: #2980b9;
            margin-bottom: 8px;
            font-size: 16px;
        }
        
        .answer-text {
            color: #27ae60;
            font-weight: 600;
            margin-bottom: 10px;
            font-size: 16px;
        }
        
        .explanation {
            color: #555;
            font-size: 15px;
            line-height: 1.7;
            border-top: 1px dashed #ddd;
            padding-top: 12px;
            margin-top: 10px;
        }
        
        .no-results {
            text-align: center;
            padding: 50px 20px;
            color: #777;
            font-size: 18px;
        }
        
        footer {
            text-align: center;
            padding: 20px;
            color: #777;
            font-size: 14px;
            border-top: 1px solid #eee;
            margin-top: 20px;
        }
        
        /* 新增：返回顶部按钮样式 */
        #backToTop {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            background-color: #2980b9;
            color: white;
            border: none;
            cursor: pointer;
            font-size: 20px;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
            transition: all 0.3s;
            z-index: 1000;
            display: none;
        }
        
        #backToTop:hover {
            background-color: #1a5fb4;
            transform: translateY(-3px);
            box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
        }
        
        /* 新增：清除所有筛选按钮样式 */
        #clearFiltersBtn {
            padding: 8px 16px;
            background-color: #e74c3c;
            color: white;
            border: none;
            border-radius: 6px;
            cursor: pointer;
            font-size: 14px;
            transition: all 0.2s;
            margin-left: 15px;
        }
        
        #clearFiltersBtn:hover {
            background-color: #c0392b;
        }
        
        .clear-filters-link {
            display: none; /* 隐藏原来的链接 */
        }
        
        @media (max-width: 768px) {
            body {
                padding: 10px;
            }
            
            .container {
                border-radius: 8px;
            }
            
            header {
                padding: 20px 15px;
            }
            
            h1 {
                font-size: 24px;
            }
            
            .search-section, .results-info, .questions-container {
                padding: 20px 15px;
            }
            
            .question-card {
                padding: 18px;
            }
            
            .results-info {
                flex-direction: column;
                align-items: flex-start;
                gap: 10px;
            }
            
            #backToTop {
                bottom: 20px;
                right: 20px;
                width: 45px;
                height: 45px;
                font-size: 18px;
            }
        }