* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f5f7fa;
            padding: 20px;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: space-between;
        }
        
        /* 标题区域 */
        .page-header {
            text-align: center;
            margin-bottom: 30px;
            max-width: 800px;
            width: 100%;
        }
        
        .page-header h1 {
            font-size: 2.2rem;
            color: #1a2a6c;
            margin-bottom: 10px;
            background: linear-gradient(135deg, #1a2a6c, #3a7bd5);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        
        .page-header p {
            color: #666;
            font-size: 1.1rem;
            line-height: 1.6;
        }
        
        /* 导航栏容器 */
        .navigation-container {
            width: 100%;
            max-width: 1200px;
            background: white;
            border-radius: 12px;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
            overflow: hidden;
            margin-bottom: 30px;
        }
        
        /* 主模块导航 */
        .main-nav {
            display: flex;
            background: linear-gradient(to right, #1a2a6c, #3a7bd5);
            padding: 0;
        }
        
        .main-nav-item {
            flex: 1;
            padding: 22px;
            background: none;
            border: none;
            color: white;
            font-size: 1.2rem;
            font-weight: 600;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: space-between;
            transition: all 0.3s ease;
        }
        
        .main-nav-item:hover {
            background-color: rgba(255, 255, 255, 0.1);
        }
        
        .main-nav-item.active {
            background-color: rgba(255, 255, 255, 0.2);
        }
        
        .main-nav-item i {
            font-size: 1.4rem;
            margin-right: 12px;
        }
        
        .nav-arrow {
            font-size: 1rem;
            transition: transform 0.4s ease;
        }
        
        .main-nav-item.active .nav-arrow {
            transform: rotate(180deg);
        }
        
        /* 子模块容器 */
        .submodules-container {
            display: none;
            padding: 30px;
            background-color: #f8fafc;
            animation: slideDown 0.5s ease-out;
        }
        
        @keyframes slideDown {
            from {
                opacity: 0;
                transform: translateY(-15px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        .submodules-container.active {
            display: block;
        }
        
        .submodules-title {
            color: #2c3e50;
            font-size: 1.5rem;
            margin-bottom: 25px;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            text-align: center;
        }
        
        /* 子模块网格 */
        .submodules-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: 25px;
            justify-items: center;
        }
        
        /* 子模块卡片 */
        .submodule-card {
            background-color: white;
            border-radius: 10px;
            padding: 22px;
            border-left: 4px solid #3a7bd5;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
            cursor: pointer;
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
            width: 100%;
            max-width: 320px;
        }
        
        .submodule-card:hover {
            transform: translateY(-7px);
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.12);
        }
        
        .submodule-card.active {
            border-left-color: #1a2a6c;
            background-color: #f0f7ff;
        }
        
        .submodule-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-bottom: 15px;
        }
        
        .submodule-title {
            font-size: 1.25rem;
            font-weight: 600;
            color: #2c3e50;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .submodule-title i {
            color: #3a7bd5;
        }
        
        .submodule-badge {
            background-color: #e9f5ff;
            color: #3a7bd5;
            font-size: 0.75rem;
            padding: 4px 10px;
            border-radius: 12px;
            font-weight: 600;
        }
        
        .submodule-desc {
            color: #666;
            font-size: 0.95rem;
            line-height: 1.5;
            margin-bottom: 15px;
            text-align: left;
        }
        
        .submodule-arrow {
            color: #aaa;
            transition: transform 0.3s ease;
        }
        
        .submodule-card.active .submodule-arrow {
            transform: rotate(90deg);
            color: #3a7bd5;
        }
        
        /* 孙模块容器 */
        .grandchild-container {
            display: none;
            background-color: #f0f7ff;
            border-radius: 8px;
            padding: 0;
            margin-top: 18px;
            overflow: hidden;
            animation: expandHeight 0.4s ease-out;
        }
        
        @keyframes expandHeight {
            from { 
                max-height: 0;
                opacity: 0;
            }
            to { 
                max-height: 500px;
                opacity: 1;
            }
        }
        
        .grandchild-container.active {
            display: block;
        }
        
        .grandchild-header {
            background-color: #e1ecff;
            padding: 14px 18px;
            font-weight: 600;
            color: #2c3e50;
            font-size: 0.95rem;
            text-align: center;
        }
        
        .grandchild-list {
            padding: 18px;
        }
        
        .grandchild-item {
            display: flex;
            align-items: center;
            padding: 14px 16px;
            background-color: white;
            border-radius: 8px;
            margin-bottom: 12px;
            text-decoration: none;
            color: #333;
            transition: all 0.2s ease;
            box-shadow: 0 3px 8px rgba(0, 0, 0, 0.04);
        }
        
        .grandchild-item:hover {
            transform: translateX(5px);
            box-shadow: 0 6px 15px rgba(0, 0, 0, 0.09);
            background-color: #f9fcff;
        }
        
        .grandchild-item i {
            color: #3a7bd5;
            margin-right: 12px;
            font-size: 0.95rem;
            width: 20px;
            text-align: center;
        }
        
        .grandchild-item span {
            font-weight: 500;
            flex-grow: 1;
        }
        
        .grandchild-item .item-arrow {
            color: #aaa;
            font-size: 0.8rem;
        }
        
        /* 响应式设计 */
        @media (max-width: 1000px) {
            .submodules-grid {
                grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
            }
        }
        
        @media (max-width: 768px) {
            .main-nav {
                flex-direction: column;
            }
            
            .submodules-grid {
                grid-template-columns: 1fr;
                max-width: 500px;
                margin: 0 auto;
            }
            
            .page-header h1 {
                font-size: 1.8rem;
            }
            
            .page-header p {
                font-size: 1rem;
            }
        }
        
        /* 状态提示 */
        .status-indicator {
            padding: 18px 30px;
            background-color: #f0f7ff;
            border-top: 1px solid #e1ecff;
            font-size: 0.95rem;
            color: #3a7bd5;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }
        
        .status-indicator i {
            font-size: 1.1rem;
        }
        
        .status-text {
            font-weight: 500;
        }
        
        /* Footer样式 */
        .page-footer {
            width: 100%;
            max-width: 1200px;
            padding: 25px;
            margin-top: 20px;
            text-align: center;
            color: #666;
            border-top: 1px solid #eaeaea;
        }
        
        .footer-content {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 10px;
        }
        
        .footer-links {
            display: flex;
            gap: 25px;
            margin-bottom: 10px;
            flex-wrap: wrap;
            justify-content: center;
        }
        
        .footer-links a {
            color: #555;
            text-decoration: none;
            font-size: 0.9rem;
            transition: color 0.2s;
        }
        
        .footer-links a:hover {
            color: #3a7bd5;
        }
        
        .icp-info {
            font-size: 0.9rem;
            color: #888;
            margin-top: 5px;
        }
        
        .copyright {
            font-size: 0.85rem;
            color: #999;
            margin-top: 5px;
        }
        
        /* 居中辅助类 */
        .center-content {
            display: flex;
            flex-direction: column;
            align-items: center;
            width: 100%;
        }