* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: "Microsoft Yahei", sans-serif;
        }
        /* 头部容器 */
        header {
            width: 100%;
            padding: 10px 20px;
            background-color: #fff;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
            position: relative; /* 为移动端弹窗定位做准备 */
        }
        /* 头部主容器 */
        .header-main {
            max-width: 1200px;
            margin: 0 auto;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
        }
        /* Logo 区域 */
        .logo-section {
            display: flex;
            align-items: center;
            margin-bottom: 15px;
        }
        .logo {
           
            height: 80px;
            margin-right: 10px;
        }
        .brand-info h1 {
            font-size: 24px;
            color: #009688;
            margin-bottom: 2px;
        }
        .brand-info p {
            font-size: 14px;
            color: #666;
            line-height: 1.4;
        }
        /* 搜索区域 - 调整PC端热搜位置 */
        .search-section {
            display: flex;
            align-items: center;
            margin-bottom: 15px;
            width: 100%;
            max-width: 400px;
            flex-wrap: wrap; /* 让热搜能换行到搜索框下方 */
        }
        .search-box {
            display: flex;
            width: 100%; /* 搜索框+按钮占满父容器宽度 */
        }
        .search-input {
            flex: 1;
            padding: 8px 12px;
            border: 1px solid #ddd;
            border-radius: 4px 0 0 4px;
            outline: none;
            font-size: 14px;
        }
        .search-btn {
            padding: 8px 20px;
            background-color: #2196F3;
            color: #fff;
            border: none;
            border-radius: 0 4px 4px 0;
            cursor: pointer;
            font-size: 14px;
        }
        .search-btn:hover {
            background-color: #1976D2;
        }
        .hot-keywords {
            font-size: 12px;
            color: #666;
            margin-top: 5px;
            width: 100%;
        }
        .hot-keywords span {
            margin-right: 8px;
        }
        /* 导航菜单 - 调整为满版心宽度且均分 */
        nav {
            width: 100%;
            border-top: 1px solid #eee;
            padding-top: 10px;
        }
        .nav-list {
            display: flex;
            list-style: none;
            width: 100%; /* 占满版心宽度 */
        }
        .nav-item {
            flex: 1; /* 均分宽度 */
            margin-right: 0; /* 移除原有右侧间距 */
            margin-bottom: 10px;
            position: relative; /* 为二级菜单定位 */
            text-align: center; /* 文字居中显示 */
        }
        .nav-item a {
            display: flex;
            align-items: center;
            justify-content: center; /* 图标+文字整体居中 */
            text-decoration: none;
            color: #333;
            font-size: 15px;
            padding: 8px 0;
            width: 100%; /* 链接占满nav-item宽度 */
                font-weight: bold;
                line-height: 24px;
        }
        .nav-item a:hover {
            color: #009688;
        }
        .nav-item.active{
         background-color: #009688;   
        }
        .nav-item.active a {
            
            color: #fff;
            padding: 8px 0; /* 取消左右padding，保证均分效果 */
            border-radius: 4px;
            width: 100%;
        }
        .nav-item i {
            margin-right: 6px;
            font-size: 16px;
        }
        /* 二级菜单样式 */
        .sub-nav {
            display: none;
            position: absolute;
            top: 100%;
            left: 0;
            background-color: #fff;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
            border-radius: 4px;
            padding: 10px 0;
            width: 100%; /* 二级菜单宽度和父级一致 */
            min-width: unset; /* 取消最小宽度限制 */
            z-index: 999;
        }
        .sub-nav li {
            list-style: none;
            padding: 0 15px;
            text-align: center; /* 二级菜单文字左对齐 */
        }
        .sub-nav li a:hover{
            background-color: #009688 !important;
            color:#fff !important;
        }
        .sub-nav li a {
            padding: 8px 0;
            font-size: 14px;
            display: block;
            justify-content: flex-start; /* 二级菜单链接左对齐 */
            color:#000 !important;
        }
        .nav-item:hover .sub-nav {
            display: block;
        }
        /* 移动端菜单按钮 */
        .mobile-menu-btn {
            display: none;
            background: none;
            border: none;
            font-size: 24px;
            color: #009688;
            cursor: pointer;
            padding: 5px;
        }
        /* 移动端导航弹窗 */
        .mobile-nav {
            display: none;
            position: absolute;
            top: 100%;
            left: 0;
            right: 0;
            background-color: #fff;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
            padding: 20px;
            z-index: 9999;
        }
        .mobile-nav .nav-list {
            flex-direction: column;
            width: 100%;
        }
        .mobile-nav .nav-item {
            flex: none; /* 移动端取消均分 */
            margin-right: 0;
            margin-bottom: 15px;
            border-bottom: 1px solid #eee;
            padding-bottom: 10px;
            text-align: left; /* 移动端文字左对齐 */
        }
        .mobile-nav .nav-item a {
            font-size: 16px;
            justify-content: flex-start; /* 移动端链接左对齐 */
        }
        .mobile-nav .sub-nav {
            position: static;
            box-shadow: none;
            padding-left: 20px;
            margin-top: 10px;
            width: 100%;
        }
        /* 移动端适配 */
        @media (max-width: 768px) {
            /* 隐藏PC端导航和搜索 */
            nav, .search-section {
                display: none;
            }
            /* 显示移动端菜单按钮 */
            .mobile-menu-btn {
                display: block;
            }
            /* 调整头部布局为logo+菜单按钮 */
            .header-main {
                flex-direction: row;
                align-items: center;
            }
            .logo-section {
                margin-bottom: 0;
            }
            /* 移动端显示搜索 */
            .mobile-nav .search-section {
                display: block;
                max-width: 100%;
                margin-bottom: 20px;
                padding-bottom: 20px;
                border-bottom: 1px solid #eee;
            }
        }
        @media (max-width: 480px) {
            .brand-info h1 {
                font-size: 20px;
            }
            .brand-info p {
                font-size: 12px;
            }
            .logo {
              
                height: 50px;
            }
        }