diff --git a/components/department-dashboard/PeopleStructureDashboard.test.tsx b/components/department-dashboard/PeopleStructureDashboard.test.tsx
index cd43492b..5dceef5d 100644
--- a/components/department-dashboard/PeopleStructureDashboard.test.tsx
+++ b/components/department-dashboard/PeopleStructureDashboard.test.tsx
@@ -14,6 +14,7 @@ jest.mock('@/components/organization/OrganizationWorkspace', () => ({
       data-embedded={String(props.embedded)}
       data-scope={String(props.scopeRootName)}
       data-heading={String(props.heading)}
+      data-tree-as-secondary-sidebar={String(props.treeAsSecondarySidebar)}
     >
       {String(props.description)}
     </div>
@@ -28,6 +29,7 @@ describe('PeopleStructureDashboard', () => {
     expect(screen.getByTestId('organization-workspace')).toHaveAttribute('data-embedded', 'true')
     expect(screen.getByTestId('organization-workspace')).toHaveAttribute('data-scope', '品牌中心')
     expect(screen.getByTestId('organization-workspace')).toHaveAttribute('data-heading', '人员架构')
+    expect(screen.getByTestId('organization-workspace')).toHaveAttribute('data-tree-as-secondary-sidebar', 'true')
     expect(screen.getByText(/公司组织架构 · 品牌中心在职人员/)).toBeInTheDocument()
   })
 })
diff --git a/components/department-dashboard/PeopleStructureDashboard.tsx b/components/department-dashboard/PeopleStructureDashboard.tsx
index 02c1bc99..28207b07 100644
--- a/components/department-dashboard/PeopleStructureDashboard.tsx
+++ b/components/department-dashboard/PeopleStructureDashboard.tsx
@@ -15,6 +15,7 @@ export default function PeopleStructureDashboard() {
           scopeRootName="品牌中心"
           heading="人员架构"
           description="公司组织架构 · 品牌中心在职人员 · 数据源：HR 花名册（每日 02:00 自动同步）"
+          treeAsSecondarySidebar
         />
       </div>
     </DepartmentShell>
diff --git a/components/organization/OrganizationWorkspace.tsx b/components/organization/OrganizationWorkspace.tsx
index 573bd70d..c2b4fbb6 100644
--- a/components/organization/OrganizationWorkspace.tsx
+++ b/components/organization/OrganizationWorkspace.tsx
@@ -98,6 +98,7 @@ type OrganizationWorkspaceProps = {
   scopeRootName?: string
   heading?: string
   description?: string
+  treeAsSecondarySidebar?: boolean
 }
 
 function findOrganizationNode(nodes: OrgNode[], name: string): OrgNode | null {
@@ -115,6 +116,7 @@ export default function OrganizationWorkspace({
   scopeRootName,
   heading = '组织架构',
   description = '品牌中心在职人员 · 数据源：HR 花名册（每日 02:00 自动同步）',
+  treeAsSecondarySidebar = false,
 }: OrganizationWorkspaceProps) {
   const { data: session, status } = useSession()
   const router = useRouter()
@@ -296,10 +298,10 @@ export default function OrganizationWorkspace({
   }
 
   const content = (
-    <div className="max-w-[1400px] mx-auto px-5 py-6">
+    <div className={treeAsSecondarySidebar ? 'w-full' : 'mx-auto max-w-[1400px] px-5 py-6'}>
       {/* direction: cloud-quarry (seed 32cb33b5) — THESIS: 部门即层叠石料块，人员是块上铭牌 */}
         {/* 页头 */}
-        <div className="mb-5 flex flex-col gap-4 sm:flex-row sm:items-end sm:justify-between">
+        <div className={`${treeAsSecondarySidebar ? 'border-b border-[#e2e8f0] bg-white px-5 py-5 sm:px-7' : 'mb-5'} flex flex-col gap-4 sm:flex-row sm:items-end sm:justify-between`}>
           <div>
             <h1 className="text-[26px] font-bold text-[#1a1c1d] tracking-tight">{heading}</h1>
             <p className="text-[13px] text-[#86898e] mt-1">{description}</p>
@@ -331,26 +333,30 @@ export default function OrganizationWorkspace({
         </div>
 
         {error && (
-          <div className="bg-[#fdf6e9] border border-[#e8c98a] text-[#a0671c] rounded-lg px-4 py-3 text-[13px] mb-4">
+          <div className={`${treeAsSecondarySidebar ? 'mx-5 mt-4 sm:mx-7' : 'mb-4'} rounded-lg border border-[#e8c98a] bg-[#fdf6e9] px-4 py-3 text-[13px] text-[#a0671c]`}>
             {error}
           </div>
         )}
 
         {loading && !data ? (
-          <div className="bg-white rounded-lg border border-[#e7e8ea] shadow-sm p-10 text-center text-[#86898e] text-sm">
+          <div className={`${treeAsSecondarySidebar ? 'm-5 sm:m-7' : ''} rounded-lg border border-[#e7e8ea] bg-white p-10 text-center text-sm text-[#86898e] shadow-sm`}>
             加载中…
           </div>
         ) : data ? (
-          <div className="grid grid-cols-1 lg:grid-cols-[300px_1fr] gap-5 items-start">
+          <div className={`grid grid-cols-1 items-start ${treeAsSecondarySidebar ? 'gap-0 lg:grid-cols-[232px_minmax(0,1fr)] lg:items-stretch' : 'gap-5 lg:grid-cols-[300px_1fr]'}`}>
             {/* 左侧：组织树 */}
-            <aside className="bg-white rounded-lg border border-[#e7e8ea] shadow-sm overflow-hidden">
-              <div className="px-4 py-3 border-b border-[#eef0f3] flex items-center justify-between">
-                <span className="text-[12px] font-semibold text-[#1a1c1d]">
+            <aside className={treeAsSecondarySidebar
+              ? 'overflow-hidden border-b border-[#e2e8f0] bg-[#f8fafc] lg:min-h-0 lg:border-b-0 lg:border-r'
+              : 'overflow-hidden rounded-lg border border-[#e7e8ea] bg-white shadow-sm'}
+              aria-label={treeAsSecondarySidebar ? '人员架构二级导航' : undefined}
+            >
+              <div className={`${treeAsSecondarySidebar ? 'border-b border-[#e2e8f0] px-4 py-4' : 'border-b border-[#eef0f3] px-4 py-3'} flex items-center justify-between`}>
+                <span className={`${treeAsSecondarySidebar ? 'text-sm font-bold text-[#101828]' : 'text-[12px] font-semibold text-[#1a1c1d]'}`}>
                   {scopeRootName ? `${scopeRootName}组织架构` : '组织架构'}
                 </span>
-                <span className="text-[11px] text-[#86898e]">{scopedTree.length} 顶层节点</span>
+                <span className={`${treeAsSecondarySidebar ? 'text-xs text-[#66758b]' : 'text-[11px] text-[#86898e]'}`}>{scopedTree.length} 顶层节点</span>
               </div>
-              <nav className="max-h-[calc(100vh-260px)] overflow-y-auto py-2" aria-label="组织树">
+              <nav className={`${treeAsSecondarySidebar ? 'max-h-[42vh] p-2 lg:max-h-[calc(100dvh-188px)] lg:py-4' : 'max-h-[calc(100vh-260px)] py-2'} overflow-y-auto`} aria-label="组织树">
                 {scopeRootName && scopedTree.length === 0 && (
                   <p className="px-4 py-8 text-center text-[13px] leading-6 text-[#86898e]">
                     未找到“{scopeRootName}”组织节点
@@ -447,7 +453,10 @@ export default function OrganizationWorkspace({
             </aside>
 
             {/* 右侧：人员明细 */}
-            <section className="bg-white rounded-lg border border-[#e7e8ea] shadow-sm overflow-hidden">
+            <section className={treeAsSecondarySidebar
+              ? 'min-w-0 overflow-hidden bg-white'
+              : 'overflow-hidden rounded-lg border border-[#e7e8ea] bg-white shadow-sm'}
+            >
               <div className="px-5 py-4 border-b border-[#eef0f3]">
                 <div className="flex items-center justify-between gap-4">
                   <div className="flex items-center gap-2 min-w-0">