/* ========= Subbanner 图片效果 ========= */
        .subbanner {
            width: 100%;
            height: 200px;
            background-image: linear-gradient(135deg, rgba(155,123,92,0.8), rgba(107,78,58,0.8)), url(../images/subbanner1.jpg);
            background-size: cover;
            background-position: center 30%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            text-align: center;}
        .subbanner h2 {
            font-size: 2.5rem;
            font-weight: 700;
            letter-spacing: 2px;
            text-shadow: 0 2px 8px rgba(0,0,0,0.3);}
        .subbanner p {
            font-size: 1rem;
            margin-top: 8px;
            opacity: 0.9;}
        @media (max-width: 768px) {
            .subbanner { height: 140px;}
            .subbanner h2 { font-size: 1.5rem;}
        }

        /* ========= 二级列表页核心布局 ========= */
        .page-content {
            padding: 40px 0;}
        .two-column-layout {
            display: flex;
            gap: 40px;
            flex-wrap: wrap;}
        /* 左侧菜单栏 */
        .sidebar-menu {
            flex: 0 0 300px;
            background: var(--light-bg);
            border-radius: 20px;
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border-light);
            overflow: hidden;
            align-self: start;}
        /* 栏目导航标题栏（可折叠） */
        .sidebar-header {
            background-image: linear-gradient(135deg, var(--accent-brown), var(--accent-dark));
            background-size: cover;
            background-position: center;
            padding: 16px 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            cursor: pointer;
            transition: background 0.2s;
            border-bottom: 1px solid var(--border-light);}
        .sidebar-header h3 {
            font-size: 1.4rem;
            font-weight: 700;
            color: white;
            letter-spacing: 1px;
            text-shadow: 0 1px 3px rgba(0,0,0,0.2);
            margin: 0;}
        .sidebar-header .toggle-icon {
            color: white;
            font-size: 1.2rem;
            transition: transform 0.2s;}
        /* 菜单内容容器 */
        .menu-content {
            display: block;}
        /* 树形菜单样式 */
        .tree-menu {
            list-style: none;
            padding: 8px 0;}
        .tree-menu li {
            list-style: none;
            margin: 0;
            padding: 0;}
        .tree-menu .menu-item {
            display: block;
            padding: 10px 20px;
            color: var(--text-dark);
            font-weight: 500;
            cursor: pointer;
            transition: all 0.2s;
            position: relative;}
        .tree-menu .menu-item > span {
            display: flex;
            justify-content: space-between;
            align-items: center;}
        .tree-menu .menu-item:hover {
            background: #F5F2E9;
            color: var(--accent-brown);}
        .tree-menu .has-children > .menu-item {
            font-weight: 600;}
        .tree-menu .children {
            list-style: none;
            padding-left: 20px;
            display: none;}
        .tree-menu .children.open {
            display: block;}
        .tree-menu .toggle-icon {
            font-size: 0.7rem;
            transition: transform 0.2s;}
        .tree-menu .has-children.open > .menu-item .toggle-icon {
            transform: rotate(90deg);}
        .tree-menu .children .children {
            padding-left: 20px;}
        .tree-menu .menu-item.active {
            background: var(--primary-warm);
            color: var(--accent-brown);
            border-left: 3px solid var(--accent-brown);}

        /* 右侧列表区 */
        .list-content {
            flex: 1;
            min-width: 260px;
            background: var(--light-bg);
            border-radius: 20px;
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border-light);
            padding: 20px 24px;}
        /* 面包屑导航 */
        .breadcrumb {
            margin-bottom: 20px;
            padding-bottom: 12px;
            border-bottom: 1px solid var(--border-light);
            font-size: 0.85rem;
            color: var(--text-gray);}
        .breadcrumb a {
            color: var(--accent-brown);}
        .breadcrumb a:hover {
            text-decoration: underline;}
        .breadcrumb i {
            margin: 0 6px;
            font-size: 0.7rem;}
        /* 文章列表 */
        .list-header {
            margin-bottom: 20px;}
        .list-header h3 {
            font-size: 1.5rem;
            font-weight: 600;
            color: var(--text-dark);}
        .article-list {
            list-style: none;}
        .article-item {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 14px 0;
            border-bottom: 1px dashed var(--border-light);
            transition: all 0.2s;}
        .article-item:hover {
            background: #FAFBF1;
            padding-left: 8px;}
        .article-title {
            font-weight: 500;
            color: var(--text-dark);
            font-size: 1rem;
            flex: 1;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            margin-right: 20px;}
        .article-title a:hover {
            color: var(--accent-brown);}
        .article-date {
            font-size: 0.8rem;
            color: var(--text-gray);
            background: #F5F2E9;
            padding: 4px 12px;
            border-radius: 20px;
            white-space: nowrap;}
        .more-link {
            display: inline-block;
            margin-top: 20px;
            color: var(--accent-brown);
            font-weight: 500;}
        .more-link i {
            margin-left: 4px;}

        /* ========= 移动端左侧菜单折叠功能：在栏目导航行内整合 ========= */
        @media (max-width: 992px) {
            .two-column-layout {
                flex-direction: column;}
            .sidebar-menu {
                flex: auto;
                width: 100%;}
            /* 移动端默认菜单内容收缩 */
            .menu-content {
                display: none;}
            .menu-content.open {
                display: block;}
        }
        /* 桌面端始终展开菜单，隐藏折叠图标（不显示点击效果） */
        @media (min-width: 993px) {
            .sidebar-header {
                cursor: default;}
            .sidebar-header .toggle-icon {
                display: none;}
            .menu-content {
                display: block !important;}
        }