diff --git a/fe-admin/src/pages/pe/PurchaseEvaluationsListPage.tsx b/fe-admin/src/pages/pe/PurchaseEvaluationsListPage.tsx
index c086933..000b5e5 100644
--- a/fe-admin/src/pages/pe/PurchaseEvaluationsListPage.tsx
+++ b/fe-admin/src/pages/pe/PurchaseEvaluationsListPage.tsx
@@ -115,21 +115,13 @@ export function PurchaseEvaluationsListPage() {
   // Đã duyệt/Từ chối loại bỏ). BE /inbox hiện loose UAT có thể trả phiếu Nháp →
   // FE filter để UX đúng kỳ vọng. Phân quyền strict V2 BE pending Session 18+.
 
-  // Plan AG Chunk A — Data transform useMemo group nested 2-level Project > Gói thầu
-  // Filter (pendingMe → DaGuiDuyet) áp dụng TRƯỚC group để empty state đúng.
-  // Normalize TenGoiThau: trim + toLowerCase làm group key, display raw đầu tiên.
-  // Fallback: "(Dự án đã xoá)" empty projectName + "(Chưa phân loại)" empty TenGoiThau.
-  // Sort vi locale A-Z cả 2 cấp.
-  type GoiThauGroup = {
-    displayName: string
-    normalizedKey: string
-    items: PeListItem[]
-  }
+  // Plan AG2 — Group 1-level Project > PE (drop tầng gói thầu per anh feedback 2026-05-21:
+  // "gói thầu thì ko cần thiết phải treedow"). Filter (pendingMe → DaGuiDuyet) TRƯỚC group.
+  // Fallback "(Dự án đã xoá)" empty projectName. Sort vi locale Project A-Z + PE createdAt DESC.
   type ProjectGroup = {
     projectId: string | null
     projectName: string
-    goiThauList: GoiThauGroup[]
-    totalCount: number
+    items: PeListItem[]
   }
   const projectGroups = useMemo<ProjectGroup[]>(() => {
     const filtered = pendingMe
@@ -140,35 +132,24 @@ export function PurchaseEvaluationsListPage() {
       const projKey = p.projectId ?? '__no_project__'
       const projName = p.projectName?.trim() || '(Dự án đã xoá)'
       if (!projectMap.has(projKey)) {
-        projectMap.set(projKey, { projectId: p.projectId ?? null, projectName: projName, goiThauList: [], totalCount: 0 })
+        projectMap.set(projKey, { projectId: p.projectId ?? null, projectName: projName, items: [] })
       }
-      const pg = projectMap.get(projKey)!
-      const rawGT = (p.tenGoiThau ?? '').trim()
-      const normKey = rawGT.toLowerCase() || '__no_goithau__'
-      const displayGT = rawGT || '(Chưa phân loại)'
-      let gt = pg.goiThauList.find(g => g.normalizedKey === normKey)
-      if (!gt) {
-        gt = { displayName: displayGT, normalizedKey: normKey, items: [] }
-        pg.goiThauList.push(gt)
-      }
-      gt.items.push(p)
-      pg.totalCount++
+      projectMap.get(projKey)!.items.push(p)
     }
     const arr = Array.from(projectMap.values())
     arr.sort((a, b) => a.projectName.localeCompare(b.projectName, 'vi'))
     for (const pg of arr) {
-      pg.goiThauList.sort((a, b) => a.displayName.localeCompare(b.displayName, 'vi'))
+      pg.items.sort((a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime())
     }
     return arr
   }, [allRows, pendingMe])
 
   // Total row count cho header badge (pendingMe đếm filtered, Danh sách đếm BE total).
-  const totalRowCount = projectGroups.reduce((sum, pg) => sum + pg.totalCount, 0)
+  const totalRowCount = projectGroups.reduce((sum, pg) => sum + pg.items.length, 0)
 
-  // Plan AG Chunk C — Expand state localStorage persist Set<string>
-  // Default empty Set (all collapse) — bro Tra Sol expect Outlook-style closed default.
-  // Project key: projectId or '__no_project__'; Gói thầu key: `${projectId}::${normalizedGoiThau}`.
-  const STORAGE_KEY = 'pe_list_expanded_groups'
+  // Plan AG2 — Expand state localStorage Set<string> (projectId only, drop ::gtKey suffix).
+  // Default empty Set (all collapse). Single-PE project skip <details> wrapper (render flat).
+  const STORAGE_KEY = 'pe_list_expanded_projects'
   const [expandedSet, setExpandedSet] = useState<Set<string>>(() => {
     try {
       const raw = localStorage.getItem(STORAGE_KEY)
@@ -204,7 +185,7 @@ export function PurchaseEvaluationsListPage() {
         </div>
       </header>
 
-      <div className="grid flex-1 grid-cols-1 overflow-hidden lg:grid-cols-[340px_1fr_360px]">
+      <div className="grid flex-1 grid-cols-1 overflow-hidden lg:grid-cols-[400px_1fr_360px]">
         {/* Panel 1: List */}
         <aside className="flex flex-col overflow-hidden border-r border-slate-200 bg-white">
           <div className="space-y-2 border-b border-slate-200 p-3">
@@ -270,100 +251,135 @@ export function PurchaseEvaluationsListPage() {
                 <EmptyState icon={ClipboardCheck} title="Chưa có phiếu" description="Tạo phiếu mới để bắt đầu quy trình." />
               </div>
             )}
-            {/* Plan AG Chunk B — Tree view 2-level Project > Gói thầu > PE (Outlook-style).
-                <details>/<summary> HTML native (no shadcn Accordion — gap component lib fe-user).
-                Tailwind v3 named groups group/proj + group/gt cho chevron rotation animation.
-                [&::-webkit-details-marker]:hidden ẩn default disclosure triangle browser. */}
+            {/* Plan AG2 — Tree view 1-level Project > PE (drop gói thầu per anh 2026-05-21).
+                <details>/<summary> HTML native. Single-PE project → render flat card no wrapper.
+                Multi-PE project → <details> tree với toggle expand + localStorage persist.
+                Tailwind v3 named group group/proj + [&::-webkit-details-marker]:hidden. */}
             <div className="divide-y divide-slate-100">
-              {projectGroups.map(pg => (
-                <details
-                  key={pg.projectId ?? '__no_project__'}
-                  open={isExpanded(pg.projectId ?? '__no_project__')}
-                  onToggle={e => toggleExpand(pg.projectId ?? '__no_project__', (e.currentTarget as HTMLDetailsElement).open)}
-                  className="group/proj"
-                >
-                  <summary className="flex cursor-pointer items-center gap-1.5 bg-slate-50 px-3 py-2 hover:bg-slate-100 [&::-webkit-details-marker]:hidden">
-                    <svg className="h-3 w-3 shrink-0 text-slate-500 transition-transform group-open/proj:rotate-90" fill="none" viewBox="0 0 24 24" stroke="currentColor"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" /></svg>
-                    <span className="text-base">📁</span>
-                    <span className="flex-1 truncate text-[13px] font-medium text-slate-900">{pg.projectName}</span>
-                    <span className="rounded-full bg-slate-200 px-2 py-0.5 text-[10px] font-medium text-slate-700">{pg.totalCount}</span>
-                  </summary>
-                  <div className="ml-3 border-l border-slate-200">
-                    {pg.goiThauList.map(gt => {
-                      const gtKey = `${pg.projectId ?? '__no_project__'}::${gt.normalizedKey}`
-                      return (
-                        <details
-                          key={gtKey}
-                          open={isExpanded(gtKey)}
-                          onToggle={e => toggleExpand(gtKey, (e.currentTarget as HTMLDetailsElement).open)}
-                          className="group/gt"
+              {projectGroups.map(pg => {
+                const projKey = pg.projectId ?? '__no_project__'
+                // Single-PE project → render flat card (no <details> wrapper) — anh feedback "ko cần treedow"
+                if (pg.items.length === 1) {
+                  const p = pg.items[0]
+                  return (
+                    <button
+                      key={p.id}
+                      onClick={() => selectRow(p.id)}
+                      className={cn(
+                        'block w-full px-3 py-2.5 text-left transition hover:bg-slate-50',
+                        selectedId === p.id && 'bg-brand-50 ring-1 ring-inset ring-brand-200',
+                      )}
+                    >
+                      <div className="mb-1 flex items-center gap-1.5 text-[10px] uppercase tracking-wide text-slate-400">
+                        <span>📁</span>
+                        <span className="truncate">{pg.projectName}</span>
+                      </div>
+                      <div className="flex items-start justify-between gap-2">
+                        <div className="min-w-0 flex-1">
+                          <div className="truncate text-[13px] font-medium text-slate-900">{p.tenGoiThau}</div>
+                          <div className="mt-0.5 flex items-center gap-1.5 text-[11px] text-slate-500">
+                            <span className="font-mono">{p.maPhieu ?? '—'}</span>
+                          </div>
+                          {p.selectedSupplierName && (
+                            <div className="mt-0.5 truncate text-[11px] text-emerald-600">
+                              ✓ {p.selectedSupplierName}
+                            </div>
+                          )}
+                        </div>
+                        <span
+                          className={cn(
+                            'shrink-0 rounded px-1.5 py-0.5 text-[10px] font-medium',
+                            PeDisplayStatusColor[getPeDisplayStatus(p.phase)],
+                          )}
                         >
-                          <summary className="flex cursor-pointer items-center gap-1.5 px-3 py-1.5 hover:bg-slate-50 [&::-webkit-details-marker]:hidden">
-                            <svg className="h-3 w-3 shrink-0 text-slate-400 transition-transform group-open/gt:rotate-90" fill="none" viewBox="0 0 24 24" stroke="currentColor"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" /></svg>
-                            <span className="text-sm">📄</span>
-                            <span className="flex-1 truncate text-[12px] text-slate-700">{gt.displayName}</span>
-                            <span className="rounded bg-slate-100 px-1.5 py-0.5 text-[10px] text-slate-600">{gt.items.length}</span>
-                          </summary>
-                          <ul className="divide-y divide-slate-100">
-                            {gt.items.map(p => (
-                              <li key={p.id}>
-                                <button
-                                  onClick={() => selectRow(p.id)}
-                                  className={cn(
-                                    'block w-full px-3 py-2.5 text-left transition hover:bg-slate-50',
-                                    selectedId === p.id && 'bg-brand-50 ring-1 ring-inset ring-brand-200',
-                                  )}
-                                >
-                                  <div className="flex items-start justify-between gap-2">
-                                    <div className="min-w-0 flex-1">
-                                      <div className="truncate text-[13px] font-medium text-slate-900">{p.tenGoiThau}</div>
-                                      <div className="mt-0.5 flex items-center gap-1.5 text-[11px] text-slate-500">
-                                        <span className="font-mono">{p.maPhieu ?? '—'}</span>
-                                        <span>·</span>
-                                        <span className="truncate">{p.projectName}</span>
-                                      </div>
-                                      {p.selectedSupplierName && (
-                                        <div className="mt-0.5 truncate text-[11px] text-emerald-600">
-                                          ✓ {p.selectedSupplierName}
-                                        </div>
-                                      )}
-                                    </div>
-                                    <span
-                                      className={cn(
-                                        'shrink-0 rounded px-1.5 py-0.5 text-[10px] font-medium',
-                                        PeDisplayStatusColor[getPeDisplayStatus(p.phase)],
-                                      )}
-                                    >
-                                      {PeDisplayStatusLabel[getPeDisplayStatus(p.phase)]}
-                                    </span>
+                          {PeDisplayStatusLabel[getPeDisplayStatus(p.phase)]}
+                        </span>
+                      </div>
+                      <div className="mt-1 flex items-center justify-between text-[11px] text-slate-500">
+                        <span className="rounded bg-slate-100 px-1.5 py-0.5 text-slate-600">
+                          {PurchaseEvaluationTypeLabel[p.type]}
+                        </span>
+                        <span className="font-medium text-slate-600" title={`Tạo lúc ${new Date(p.createdAt).toLocaleString('vi-VN')}`}>
+                          {new Date(p.createdAt).toLocaleString('vi-VN', {
+                            day: '2-digit', month: '2-digit', year: 'numeric',
+                            hour: '2-digit', minute: '2-digit',
+                          })}
+                        </span>
+                      </div>
+                      {p.contractId && (
+                        <div className="mt-1 text-[10px] text-brand-600">✓ Đã tạo HĐ</div>
+                      )}
+                    </button>
+                  )
+                }
+                // Multi-PE project → render <details> tree
+                return (
+                  <details
+                    key={projKey}
+                    open={isExpanded(projKey)}
+                    onToggle={e => toggleExpand(projKey, (e.currentTarget as HTMLDetailsElement).open)}
+                    className="group/proj"
+                  >
+                    <summary className="flex cursor-pointer items-center gap-1.5 bg-slate-50 px-3 py-2 hover:bg-slate-100 [&::-webkit-details-marker]:hidden">
+                      <svg className="h-3 w-3 shrink-0 text-slate-500 transition-transform group-open/proj:rotate-90" fill="none" viewBox="0 0 24 24" stroke="currentColor"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" /></svg>
+                      <span className="text-base">📁</span>
+                      <span className="flex-1 truncate text-[13px] font-medium text-slate-900">{pg.projectName}</span>
+                      <span className="rounded-full bg-slate-200 px-2 py-0.5 text-[10px] font-medium text-slate-700">{pg.items.length}</span>
+                    </summary>
+                    <ul className="ml-3 divide-y divide-slate-100 border-l border-slate-200">
+                      {pg.items.map(p => (
+                        <li key={p.id}>
+                          <button
+                            onClick={() => selectRow(p.id)}
+                            className={cn(
+                              'block w-full px-3 py-2.5 text-left transition hover:bg-slate-50',
+                              selectedId === p.id && 'bg-brand-50 ring-1 ring-inset ring-brand-200',
+                            )}
+                          >
+                            <div className="flex items-start justify-between gap-2">
+                              <div className="min-w-0 flex-1">
+                                <div className="truncate text-[13px] font-medium text-slate-900">{p.tenGoiThau}</div>
+                                <div className="mt-0.5 flex items-center gap-1.5 text-[11px] text-slate-500">
+                                  <span className="font-mono">{p.maPhieu ?? '—'}</span>
+                                </div>
+                                {p.selectedSupplierName && (
+                                  <div className="mt-0.5 truncate text-[11px] text-emerald-600">
+                                    ✓ {p.selectedSupplierName}
                                   </div>
-                                  <div className="mt-1 flex items-center justify-between text-[11px] text-slate-500">
-                                    <span className="rounded bg-slate-100 px-1.5 py-0.5 text-slate-600">
-                                      {PurchaseEvaluationTypeLabel[p.type]}
-                                    </span>
-                                    {/* S23 t2 UAT: bro yêu cầu đổi SLA countdown → ngày giờ tạo phiếu.
-                                        BE list sort theo UpdatedAt DESC (fallback CreatedAt) — phiếu vừa
-                                        update (Tạo / Gửi duyệt / Trả lại) đưa lên đầu list. */}
-                                    <span className="font-medium text-slate-600" title={`Tạo lúc ${new Date(p.createdAt).toLocaleString('vi-VN')}`}>
-                                      {new Date(p.createdAt).toLocaleString('vi-VN', {
-                                        day: '2-digit', month: '2-digit', year: 'numeric',
-                                        hour: '2-digit', minute: '2-digit',
-                                      })}
-                                    </span>
-                                  </div>
-                                  {p.contractId && (
-                                    <div className="mt-1 text-[10px] text-brand-600">✓ Đã tạo HĐ</div>
-                                  )}
-                                </button>
-                              </li>
-                            ))}
-                          </ul>
-                        </details>
-                      )
-                    })}
-                  </div>
-                </details>
-              ))}
+                                )}
+                              </div>
+                              <span
+                                className={cn(
+                                  'shrink-0 rounded px-1.5 py-0.5 text-[10px] font-medium',
+                                  PeDisplayStatusColor[getPeDisplayStatus(p.phase)],
+                                )}
+                              >
+                                {PeDisplayStatusLabel[getPeDisplayStatus(p.phase)]}
+                              </span>
+                            </div>
+                            <div className="mt-1 flex items-center justify-between text-[11px] text-slate-500">
+                              <span className="rounded bg-slate-100 px-1.5 py-0.5 text-slate-600">
+                                {PurchaseEvaluationTypeLabel[p.type]}
+                              </span>
+                              {/* S23 t2 UAT: BE list sort theo UpdatedAt DESC (fallback CreatedAt) —
+                                  phiếu vừa update (Tạo / Gửi duyệt / Trả lại) đưa lên đầu list. */}
+                              <span className="font-medium text-slate-600" title={`Tạo lúc ${new Date(p.createdAt).toLocaleString('vi-VN')}`}>
+                                {new Date(p.createdAt).toLocaleString('vi-VN', {
+                                  day: '2-digit', month: '2-digit', year: 'numeric',
+                                  hour: '2-digit', minute: '2-digit',
+                                })}
+                              </span>
+                            </div>
+                            {p.contractId && (
+                              <div className="mt-1 text-[10px] text-brand-600">✓ Đã tạo HĐ</div>
+                            )}
+                          </button>
+                        </li>
+                      ))}
+                    </ul>
+                  </details>
+                )
+              })}
             </div>
           </div>
         </aside>
diff --git a/fe-user/src/pages/pe/PurchaseEvaluationsListPage.tsx b/fe-user/src/pages/pe/PurchaseEvaluationsListPage.tsx
index c086933..000b5e5 100644
--- a/fe-user/src/pages/pe/PurchaseEvaluationsListPage.tsx
+++ b/fe-user/src/pages/pe/PurchaseEvaluationsListPage.tsx
@@ -115,21 +115,13 @@ export function PurchaseEvaluationsListPage() {
   // Đã duyệt/Từ chối loại bỏ). BE /inbox hiện loose UAT có thể trả phiếu Nháp →
   // FE filter để UX đúng kỳ vọng. Phân quyền strict V2 BE pending Session 18+.
 
-  // Plan AG Chunk A — Data transform useMemo group nested 2-level Project > Gói thầu
-  // Filter (pendingMe → DaGuiDuyet) áp dụng TRƯỚC group để empty state đúng.
-  // Normalize TenGoiThau: trim + toLowerCase làm group key, display raw đầu tiên.
-  // Fallback: "(Dự án đã xoá)" empty projectName + "(Chưa phân loại)" empty TenGoiThau.
-  // Sort vi locale A-Z cả 2 cấp.
-  type GoiThauGroup = {
-    displayName: string
-    normalizedKey: string
-    items: PeListItem[]
-  }
+  // Plan AG2 — Group 1-level Project > PE (drop tầng gói thầu per anh feedback 2026-05-21:
+  // "gói thầu thì ko cần thiết phải treedow"). Filter (pendingMe → DaGuiDuyet) TRƯỚC group.
+  // Fallback "(Dự án đã xoá)" empty projectName. Sort vi locale Project A-Z + PE createdAt DESC.
   type ProjectGroup = {
     projectId: string | null
     projectName: string
-    goiThauList: GoiThauGroup[]
-    totalCount: number
+    items: PeListItem[]
   }
   const projectGroups = useMemo<ProjectGroup[]>(() => {
     const filtered = pendingMe
@@ -140,35 +132,24 @@ export function PurchaseEvaluationsListPage() {
       const projKey = p.projectId ?? '__no_project__'
       const projName = p.projectName?.trim() || '(Dự án đã xoá)'
       if (!projectMap.has(projKey)) {
-        projectMap.set(projKey, { projectId: p.projectId ?? null, projectName: projName, goiThauList: [], totalCount: 0 })
+        projectMap.set(projKey, { projectId: p.projectId ?? null, projectName: projName, items: [] })
       }
-      const pg = projectMap.get(projKey)!
-      const rawGT = (p.tenGoiThau ?? '').trim()
-      const normKey = rawGT.toLowerCase() || '__no_goithau__'
-      const displayGT = rawGT || '(Chưa phân loại)'
-      let gt = pg.goiThauList.find(g => g.normalizedKey === normKey)
-      if (!gt) {
-        gt = { displayName: displayGT, normalizedKey: normKey, items: [] }
-        pg.goiThauList.push(gt)
-      }
-      gt.items.push(p)
-      pg.totalCount++
+      projectMap.get(projKey)!.items.push(p)
     }
     const arr = Array.from(projectMap.values())
     arr.sort((a, b) => a.projectName.localeCompare(b.projectName, 'vi'))
     for (const pg of arr) {
-      pg.goiThauList.sort((a, b) => a.displayName.localeCompare(b.displayName, 'vi'))
+      pg.items.sort((a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime())
     }
     return arr
   }, [allRows, pendingMe])
 
   // Total row count cho header badge (pendingMe đếm filtered, Danh sách đếm BE total).
-  const totalRowCount = projectGroups.reduce((sum, pg) => sum + pg.totalCount, 0)
+  const totalRowCount = projectGroups.reduce((sum, pg) => sum + pg.items.length, 0)
 
-  // Plan AG Chunk C — Expand state localStorage persist Set<string>
-  // Default empty Set (all collapse) — bro Tra Sol expect Outlook-style closed default.
-  // Project key: projectId or '__no_project__'; Gói thầu key: `${projectId}::${normalizedGoiThau}`.
-  const STORAGE_KEY = 'pe_list_expanded_groups'
+  // Plan AG2 — Expand state localStorage Set<string> (projectId only, drop ::gtKey suffix).
+  // Default empty Set (all collapse). Single-PE project skip <details> wrapper (render flat).
+  const STORAGE_KEY = 'pe_list_expanded_projects'
   const [expandedSet, setExpandedSet] = useState<Set<string>>(() => {
     try {
       const raw = localStorage.getItem(STORAGE_KEY)
@@ -204,7 +185,7 @@ export function PurchaseEvaluationsListPage() {
         </div>
       </header>
 
-      <div className="grid flex-1 grid-cols-1 overflow-hidden lg:grid-cols-[340px_1fr_360px]">
+      <div className="grid flex-1 grid-cols-1 overflow-hidden lg:grid-cols-[400px_1fr_360px]">
         {/* Panel 1: List */}
         <aside className="flex flex-col overflow-hidden border-r border-slate-200 bg-white">
           <div className="space-y-2 border-b border-slate-200 p-3">
@@ -270,100 +251,135 @@ export function PurchaseEvaluationsListPage() {
                 <EmptyState icon={ClipboardCheck} title="Chưa có phiếu" description="Tạo phiếu mới để bắt đầu quy trình." />
               </div>
             )}
-            {/* Plan AG Chunk B — Tree view 2-level Project > Gói thầu > PE (Outlook-style).
-                <details>/<summary> HTML native (no shadcn Accordion — gap component lib fe-user).
-                Tailwind v3 named groups group/proj + group/gt cho chevron rotation animation.
-                [&::-webkit-details-marker]:hidden ẩn default disclosure triangle browser. */}
+            {/* Plan AG2 — Tree view 1-level Project > PE (drop gói thầu per anh 2026-05-21).
+                <details>/<summary> HTML native. Single-PE project → render flat card no wrapper.
+                Multi-PE project → <details> tree với toggle expand + localStorage persist.
+                Tailwind v3 named group group/proj + [&::-webkit-details-marker]:hidden. */}
             <div className="divide-y divide-slate-100">
-              {projectGroups.map(pg => (
-                <details
-                  key={pg.projectId ?? '__no_project__'}
-                  open={isExpanded(pg.projectId ?? '__no_project__')}
-                  onToggle={e => toggleExpand(pg.projectId ?? '__no_project__', (e.currentTarget as HTMLDetailsElement).open)}
-                  className="group/proj"
-                >
-                  <summary className="flex cursor-pointer items-center gap-1.5 bg-slate-50 px-3 py-2 hover:bg-slate-100 [&::-webkit-details-marker]:hidden">
-                    <svg className="h-3 w-3 shrink-0 text-slate-500 transition-transform group-open/proj:rotate-90" fill="none" viewBox="0 0 24 24" stroke="currentColor"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" /></svg>
-                    <span className="text-base">📁</span>
-                    <span className="flex-1 truncate text-[13px] font-medium text-slate-900">{pg.projectName}</span>
-                    <span className="rounded-full bg-slate-200 px-2 py-0.5 text-[10px] font-medium text-slate-700">{pg.totalCount}</span>
-                  </summary>
-                  <div className="ml-3 border-l border-slate-200">
-                    {pg.goiThauList.map(gt => {
-                      const gtKey = `${pg.projectId ?? '__no_project__'}::${gt.normalizedKey}`
-                      return (
-                        <details
-                          key={gtKey}
-                          open={isExpanded(gtKey)}
-                          onToggle={e => toggleExpand(gtKey, (e.currentTarget as HTMLDetailsElement).open)}
-                          className="group/gt"
+              {projectGroups.map(pg => {
+                const projKey = pg.projectId ?? '__no_project__'
+                // Single-PE project → render flat card (no <details> wrapper) — anh feedback "ko cần treedow"
+                if (pg.items.length === 1) {
+                  const p = pg.items[0]
+                  return (
+                    <button
+                      key={p.id}
+                      onClick={() => selectRow(p.id)}
+                      className={cn(
+                        'block w-full px-3 py-2.5 text-left transition hover:bg-slate-50',
+                        selectedId === p.id && 'bg-brand-50 ring-1 ring-inset ring-brand-200',
+                      )}
+                    >
+                      <div className="mb-1 flex items-center gap-1.5 text-[10px] uppercase tracking-wide text-slate-400">
+                        <span>📁</span>
+                        <span className="truncate">{pg.projectName}</span>
+                      </div>
+                      <div className="flex items-start justify-between gap-2">
+                        <div className="min-w-0 flex-1">
+                          <div className="truncate text-[13px] font-medium text-slate-900">{p.tenGoiThau}</div>
+                          <div className="mt-0.5 flex items-center gap-1.5 text-[11px] text-slate-500">
+                            <span className="font-mono">{p.maPhieu ?? '—'}</span>
+                          </div>
+                          {p.selectedSupplierName && (
+                            <div className="mt-0.5 truncate text-[11px] text-emerald-600">
+                              ✓ {p.selectedSupplierName}
+                            </div>
+                          )}
+                        </div>
+                        <span
+                          className={cn(
+                            'shrink-0 rounded px-1.5 py-0.5 text-[10px] font-medium',
+                            PeDisplayStatusColor[getPeDisplayStatus(p.phase)],
+                          )}
                         >
-                          <summary className="flex cursor-pointer items-center gap-1.5 px-3 py-1.5 hover:bg-slate-50 [&::-webkit-details-marker]:hidden">
-                            <svg className="h-3 w-3 shrink-0 text-slate-400 transition-transform group-open/gt:rotate-90" fill="none" viewBox="0 0 24 24" stroke="currentColor"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" /></svg>
-                            <span className="text-sm">📄</span>
-                            <span className="flex-1 truncate text-[12px] text-slate-700">{gt.displayName}</span>
-                            <span className="rounded bg-slate-100 px-1.5 py-0.5 text-[10px] text-slate-600">{gt.items.length}</span>
-                          </summary>
-                          <ul className="divide-y divide-slate-100">
-                            {gt.items.map(p => (
-                              <li key={p.id}>
-                                <button
-                                  onClick={() => selectRow(p.id)}
-                                  className={cn(
-                                    'block w-full px-3 py-2.5 text-left transition hover:bg-slate-50',
-                                    selectedId === p.id && 'bg-brand-50 ring-1 ring-inset ring-brand-200',
-                                  )}
-                                >
-                                  <div className="flex items-start justify-between gap-2">
-                                    <div className="min-w-0 flex-1">
-                                      <div className="truncate text-[13px] font-medium text-slate-900">{p.tenGoiThau}</div>
-                                      <div className="mt-0.5 flex items-center gap-1.5 text-[11px] text-slate-500">
-                                        <span className="font-mono">{p.maPhieu ?? '—'}</span>
-                                        <span>·</span>
-                                        <span className="truncate">{p.projectName}</span>
-                                      </div>
-                                      {p.selectedSupplierName && (
-                                        <div className="mt-0.5 truncate text-[11px] text-emerald-600">
-                                          ✓ {p.selectedSupplierName}
-                                        </div>
-                                      )}
-                                    </div>
-                                    <span
-                                      className={cn(
-                                        'shrink-0 rounded px-1.5 py-0.5 text-[10px] font-medium',
-                                        PeDisplayStatusColor[getPeDisplayStatus(p.phase)],
-                                      )}
-                                    >
-                                      {PeDisplayStatusLabel[getPeDisplayStatus(p.phase)]}
-                                    </span>
+                          {PeDisplayStatusLabel[getPeDisplayStatus(p.phase)]}
+                        </span>
+                      </div>
+                      <div className="mt-1 flex items-center justify-between text-[11px] text-slate-500">
+                        <span className="rounded bg-slate-100 px-1.5 py-0.5 text-slate-600">
+                          {PurchaseEvaluationTypeLabel[p.type]}
+                        </span>
+                        <span className="font-medium text-slate-600" title={`Tạo lúc ${new Date(p.createdAt).toLocaleString('vi-VN')}`}>
+                          {new Date(p.createdAt).toLocaleString('vi-VN', {
+                            day: '2-digit', month: '2-digit', year: 'numeric',
+                            hour: '2-digit', minute: '2-digit',
+                          })}
+                        </span>
+                      </div>
+                      {p.contractId && (
+                        <div className="mt-1 text-[10px] text-brand-600">✓ Đã tạo HĐ</div>
+                      )}
+                    </button>
+                  )
+                }
+                // Multi-PE project → render <details> tree
+                return (
+                  <details
+                    key={projKey}
+                    open={isExpanded(projKey)}
+                    onToggle={e => toggleExpand(projKey, (e.currentTarget as HTMLDetailsElement).open)}
+                    className="group/proj"
+                  >
+                    <summary className="flex cursor-pointer items-center gap-1.5 bg-slate-50 px-3 py-2 hover:bg-slate-100 [&::-webkit-details-marker]:hidden">
+                      <svg className="h-3 w-3 shrink-0 text-slate-500 transition-transform group-open/proj:rotate-90" fill="none" viewBox="0 0 24 24" stroke="currentColor"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" /></svg>
+                      <span className="text-base">📁</span>
+                      <span className="flex-1 truncate text-[13px] font-medium text-slate-900">{pg.projectName}</span>
+                      <span className="rounded-full bg-slate-200 px-2 py-0.5 text-[10px] font-medium text-slate-700">{pg.items.length}</span>
+                    </summary>
+                    <ul className="ml-3 divide-y divide-slate-100 border-l border-slate-200">
+                      {pg.items.map(p => (
+                        <li key={p.id}>
+                          <button
+                            onClick={() => selectRow(p.id)}
+                            className={cn(
+                              'block w-full px-3 py-2.5 text-left transition hover:bg-slate-50',
+                              selectedId === p.id && 'bg-brand-50 ring-1 ring-inset ring-brand-200',
+                            )}
+                          >
+                            <div className="flex items-start justify-between gap-2">
+                              <div className="min-w-0 flex-1">
+                                <div className="truncate text-[13px] font-medium text-slate-900">{p.tenGoiThau}</div>
+                                <div className="mt-0.5 flex items-center gap-1.5 text-[11px] text-slate-500">
+                                  <span className="font-mono">{p.maPhieu ?? '—'}</span>
+                                </div>
+                                {p.selectedSupplierName && (
+                                  <div className="mt-0.5 truncate text-[11px] text-emerald-600">
+                                    ✓ {p.selectedSupplierName}
                                   </div>
-                                  <div className="mt-1 flex items-center justify-between text-[11px] text-slate-500">
-                                    <span className="rounded bg-slate-100 px-1.5 py-0.5 text-slate-600">
-                                      {PurchaseEvaluationTypeLabel[p.type]}
-                                    </span>
-                                    {/* S23 t2 UAT: bro yêu cầu đổi SLA countdown → ngày giờ tạo phiếu.
-                                        BE list sort theo UpdatedAt DESC (fallback CreatedAt) — phiếu vừa
-                                        update (Tạo / Gửi duyệt / Trả lại) đưa lên đầu list. */}
-                                    <span className="font-medium text-slate-600" title={`Tạo lúc ${new Date(p.createdAt).toLocaleString('vi-VN')}`}>
-                                      {new Date(p.createdAt).toLocaleString('vi-VN', {
-                                        day: '2-digit', month: '2-digit', year: 'numeric',
-                                        hour: '2-digit', minute: '2-digit',
-                                      })}
-                                    </span>
-                                  </div>
-                                  {p.contractId && (
-                                    <div className="mt-1 text-[10px] text-brand-600">✓ Đã tạo HĐ</div>
-                                  )}
-                                </button>
-                              </li>
-                            ))}
-                          </ul>
-                        </details>
-                      )
-                    })}
-                  </div>
-                </details>
-              ))}
+                                )}
+                              </div>
+                              <span
+                                className={cn(
+                                  'shrink-0 rounded px-1.5 py-0.5 text-[10px] font-medium',
+                                  PeDisplayStatusColor[getPeDisplayStatus(p.phase)],
+                                )}
+                              >
+                                {PeDisplayStatusLabel[getPeDisplayStatus(p.phase)]}
+                              </span>
+                            </div>
+                            <div className="mt-1 flex items-center justify-between text-[11px] text-slate-500">
+                              <span className="rounded bg-slate-100 px-1.5 py-0.5 text-slate-600">
+                                {PurchaseEvaluationTypeLabel[p.type]}
+                              </span>
+                              {/* S23 t2 UAT: BE list sort theo UpdatedAt DESC (fallback CreatedAt) —
+                                  phiếu vừa update (Tạo / Gửi duyệt / Trả lại) đưa lên đầu list. */}
+                              <span className="font-medium text-slate-600" title={`Tạo lúc ${new Date(p.createdAt).toLocaleString('vi-VN')}`}>
+                                {new Date(p.createdAt).toLocaleString('vi-VN', {
+                                  day: '2-digit', month: '2-digit', year: 'numeric',
+                                  hour: '2-digit', minute: '2-digit',
+                                })}
+                              </span>
+                            </div>
+                            {p.contractId && (
+                              <div className="mt-1 text-[10px] text-brand-600">✓ Đã tạo HĐ</div>
+                            )}
+                          </button>
+                        </li>
+                      ))}
+                    </ul>
+                  </details>
+                )
+              })}
             </div>
           </div>
         </aside>