diff --git a/frontend/src/App.jsx b/frontend/src/App.jsx
index 75ec53f..9aa695b 100644
--- a/frontend/src/App.jsx
+++ b/frontend/src/App.jsx
@@ -101,7 +101,25 @@ function flattenProgramTree(node, depth = 0, rows = []) {
   return rows
 }
 
-function ProgramReviewPanel({ selectedNode, reviewForm, onReviewChange, onSaveReview }) {
+function flattenVisibleProgramTree(node, collapsedKeys, depth = 0, rows = []) {
+  if (!node) return rows
+  rows.push({ node, depth })
+  if (!collapsedKeys.has(node.key)) {
+    ;(node.children || []).forEach((child) => flattenVisibleProgramTree(child, collapsedKeys, depth + 1, rows))
+  }
+  return rows
+}
+
+function collectCollapsibleProgramKeys(node, depth = 0, keys = []) {
+  if (!node) return keys
+  if (depth > 0 && node.children?.length) keys.push(node.key)
+  ;(node.children || []).forEach((child) => collectCollapsibleProgramKeys(child, depth + 1, keys))
+  return keys
+}
+
+function ProgramReviewPanel({ selectedNode, reviewForm, onReviewChange, onSaveReview, readOnly = false, onOpenValidation }) {
+  const [isFullscreen, setIsFullscreen] = useState(false)
+
   if (!selectedNode) {
     return (
       <section className="admin-empty">
@@ -136,9 +154,10 @@ function ProgramReviewPanel({ selectedNode, reviewForm, onReviewChange, onSaveRe
       )}
 
       {selectedNode.url && (
-        <div className="program-node-preview">
+        <button type="button" className="program-node-preview" onClick={() => setIsFullscreen(true)}>
           <img src={selectedNode.url} alt={selectedNode.label} />
-        </div>
+          <span>{readOnly ? 'Cliquer pour inspecter en plein écran' : 'Cliquer pour valider en plein écran'}</span>
+        </button>
       )}
 
       {review.comment && (
@@ -149,30 +168,95 @@ function ProgramReviewPanel({ selectedNode, reviewForm, onReviewChange, onSaveRe
         </div>
       )}
 
-      <form className="admin-review-form" onSubmit={onSaveReview}>
-        <label>
-          <span>Statut de validation</span>
-          <select
-            value={reviewForm.status}
-            onChange={(event) => onReviewChange({ ...reviewForm, status: event.target.value })}
-          >
-            <option value="validated">Validé</option>
-            <option value="needs_changes">À modifier</option>
-            <option value="blocked">Bloqué</option>
-            <option value="draft">Brouillon</option>
-          </select>
-        </label>
-        <label>
-          <span>Commentaire visible par Codex</span>
-          <textarea
-            value={reviewForm.comment}
-            onChange={(event) => onReviewChange({ ...reviewForm, comment: event.target.value })}
-            placeholder="Note ce qui dépasse, ce qui est incorrect, ou ce qui doit être régénéré."
-            rows={5}
-          />
-        </label>
-        <button type="submit">Enregistrer la revue</button>
-      </form>
+      {readOnly ? (
+        <div className="admin-review-form">
+          <strong>Validation centralisée</strong>
+          <p className="muted">Cet onglet sert à explorer le programme. Les décisions éditoriales se font dans l’onglet Validation contenus.</p>
+          <button type="button" onClick={onOpenValidation}>Ouvrir dans Validation contenus</button>
+        </div>
+      ) : (
+        <form className="admin-review-form" onSubmit={onSaveReview}>
+          <label>
+            <span>Statut de validation</span>
+            <select
+              value={reviewForm.status}
+              onChange={(event) => onReviewChange({ ...reviewForm, status: event.target.value })}
+            >
+              <option value="validated">Validé</option>
+              <option value="needs_changes">À modifier</option>
+              <option value="blocked">Bloqué</option>
+              <option value="draft">Brouillon</option>
+            </select>
+          </label>
+          <label>
+            <span>Commentaire visible par Codex</span>
+            <textarea
+              value={reviewForm.comment}
+              onChange={(event) => onReviewChange({ ...reviewForm, comment: event.target.value })}
+              placeholder="Note ce qui dépasse, ce qui est incorrect, ou ce qui doit être régénéré."
+              rows={5}
+            />
+          </label>
+          <button type="submit">Enregistrer la revue</button>
+        </form>
+      )}
+
+      {isFullscreen && (
+        <div className="review-fullscreen" role="dialog" aria-modal="true" aria-label={`Revue plein écran ${selectedNode.label}`}>
+          <div className="review-fullscreen-stage">
+            <div className="review-fullscreen-head">
+              <div>
+                <span className="stage-label">{selectedNode.type}</span>
+                <h2>{selectedNode.label}</h2>
+                <p className="muted">{selectedNode.path || selectedNode.key}</p>
+              </div>
+              <button type="button" className="secondary-button" onClick={() => setIsFullscreen(false)}>
+                Fermer
+              </button>
+            </div>
+            <div className="review-fullscreen-image">
+              <img src={selectedNode.url} alt={selectedNode.label} />
+            </div>
+          </div>
+
+          <aside className="review-fullscreen-panel">
+            <h2>{readOnly ? 'Inspection' : 'Validation'}</h2>
+            {readOnly ? (
+              <div className="admin-review-form">
+                <p className="muted">Pour modifier le statut ou laisser une remarque, ouvre cet élément dans la file de validation.</p>
+                <button type="button" onClick={() => { setIsFullscreen(false); onOpenValidation?.() }}>
+                  Ouvrir dans Validation contenus
+                </button>
+              </div>
+            ) : (
+              <form className="admin-review-form" onSubmit={onSaveReview}>
+                <label>
+                  <span>Statut</span>
+                  <select
+                    value={reviewForm.status}
+                    onChange={(event) => onReviewChange({ ...reviewForm, status: event.target.value })}
+                  >
+                    <option value="validated">Validé</option>
+                    <option value="needs_changes">À modifier</option>
+                    <option value="blocked">Bloqué</option>
+                    <option value="draft">Brouillon</option>
+                  </select>
+                </label>
+                <label>
+                  <span>Commentaire</span>
+                  <textarea
+                    value={reviewForm.comment}
+                    onChange={(event) => onReviewChange({ ...reviewForm, comment: event.target.value })}
+                    placeholder="Note précisément ce qui doit être corrigé."
+                    rows={8}
+                  />
+                </label>
+                <button type="submit">Enregistrer la revue</button>
+              </form>
+            )}
+          </aside>
+        </div>
+      )}
     </section>
   )
 }
@@ -297,6 +381,7 @@ function TutorApp({ currentUser, onLogout }) {
   const [selectedProgramNodeKey, setSelectedProgramNodeKey] = useState('')
   const [programReviewForm, setProgramReviewForm] = useState({ status: 'needs_changes', comment: '' })
   const [activeAdminTab, setActiveAdminTab] = useState('overview')
+  const [collapsedProgramKeys, setCollapsedProgramKeys] = useState(() => new Set())
   const [studentProgram, setStudentProgram] = useState(null)
   const [activeAssetIndex, setActiveAssetIndex] = useState(0)
   const [activeSectionIndex, setActiveSectionIndex] = useState(0)
@@ -353,6 +438,10 @@ function TutorApp({ currentUser, onLogout }) {
 
   const lessonPercent = lessonFocus ? Math.round(lessonFocus.mastery_score) : averageScore
   const programRows = useMemo(() => flattenProgramTree(programTree).filter((row) => row.node.type !== 'root'), [programTree])
+  const visibleProgramRows = useMemo(
+    () => flattenVisibleProgramTree(programTree, collapsedProgramKeys).filter((row) => row.node.type !== 'root'),
+    [programTree, collapsedProgramKeys]
+  )
   const selectedProgramNode = useMemo(
     () => programRows.find((row) => row.node.key === selectedProgramNodeKey)?.node || null,
     [programRows, selectedProgramNodeKey]
@@ -395,6 +484,20 @@ function TutorApp({ currentUser, onLogout }) {
     setActiveSectionIndex(sectionIndex)
   }
 
+  function toggleProgramNode(node) {
+    if (!node?.children?.length) {
+      setSelectedProgramNodeKey(node?.key || '')
+      return
+    }
+    setSelectedProgramNodeKey(node.key)
+    setCollapsedProgramKeys((current) => {
+      const next = new Set(current)
+      if (next.has(node.key)) next.delete(node.key)
+      else next.add(node.key)
+      return next
+    })
+  }
+
   useEffect(() => {
     isRecordingRef.current = isRecording
   }, [isRecording])
@@ -759,6 +862,7 @@ function TutorApp({ currentUser, onLogout }) {
       const data = await apiFetch('/admin/program/tree')
       setProgramTree(data)
       setSelectedProgramNodeKey((current) => current || data.children?.[0]?.key || '')
+      setCollapsedProgramKeys(new Set(collectCollapsibleProgramKeys(data)))
     } catch (error) {
       setErrorMessage(error.message || 'Impossible de charger l’arborescence du programme.')
     }
@@ -1987,16 +2091,26 @@ function TutorApp({ currentUser, onLogout }) {
                   <button type="button" className="secondary-button" onClick={loadProgramTree}>Rafraîchir</button>
                 </div>
                 <div className="program-tree-list">
-                  {programRows.map(({ node, depth }) => (
-                    <button key={node.key} type="button" className={`program-tree-row ${selectedProgramNodeKey === node.key ? 'active' : ''}`} style={{ paddingLeft: `${0.65 + depth * 1.05}rem` }} onClick={() => setSelectedProgramNodeKey(node.key)}>
-                      <span>{node.label}</span>
+                  {visibleProgramRows.map(({ node, depth }) => (
+                    <button key={node.key} type="button" className={`program-tree-row ${selectedProgramNodeKey === node.key ? 'active' : ''}`} style={{ paddingLeft: `${0.65 + depth * 1.05}rem` }} onClick={() => toggleProgramNode(node)}>
+                      <span className="tree-label">
+                        <b>{node.children?.length ? (collapsedProgramKeys.has(node.key) ? '+' : '-') : ''}</b>
+                        {node.label}
+                      </span>
                       <em>{node.type}</em>
                       {node.review?.status && <strong>{node.review.status}</strong>}
                     </button>
                   ))}
                 </div>
               </div>
-              <ProgramReviewPanel selectedNode={selectedProgramNode} reviewForm={programReviewForm} onReviewChange={setProgramReviewForm} onSaveReview={saveProgramReview} />
+              <ProgramReviewPanel
+                selectedNode={selectedProgramNode}
+                reviewForm={programReviewForm}
+                onReviewChange={setProgramReviewForm}
+                onSaveReview={saveProgramReview}
+                readOnly
+                onOpenValidation={() => setActiveAdminTab('validation')}
+              />
             </section>
           )}
 
diff --git a/frontend/src/styles.css b/frontend/src/styles.css
index 6b0e829..5e012ad 100644
--- a/frontend/src/styles.css
+++ b/frontend/src/styles.css
@@ -350,6 +350,67 @@ button:disabled { opacity: 0.5; cursor: not-allowed; }
   align-items: flex-start;
 }
 
+.review-fullscreen {
+  position: fixed;
+  inset: 0;
+  z-index: 30;
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) 360px;
+  gap: 1rem;
+  padding: 1rem;
+  background: rgba(248, 250, 252, 0.98);
+}
+
+.review-fullscreen-stage,
+.review-fullscreen-panel {
+  min-height: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 1rem;
+  border: 1px solid #dbe3ef;
+  border-radius: 18px;
+  background: white;
+  box-shadow: 0 18px 50px rgba(15, 23, 42, 0.16);
+  padding: 1rem;
+}
+
+.review-fullscreen-head {
+  flex: 0 0 auto;
+  display: flex;
+  align-items: flex-start;
+  justify-content: space-between;
+  gap: 1rem;
+}
+
+.review-fullscreen-head h2,
+.review-fullscreen-head p,
+.review-fullscreen-panel h2 {
+  margin: 0;
+}
+
+.review-fullscreen-image {
+  min-height: 0;
+  flex: 1;
+  display: grid;
+  place-items: center;
+  border: 1px solid #e2e8f0;
+  border-radius: 14px;
+  background: #f8fafc;
+  overflow: hidden;
+  padding: 0.5rem;
+}
+
+.review-fullscreen-image img {
+  width: 100%;
+  height: 100%;
+  object-fit: contain;
+  display: block;
+}
+
+.review-fullscreen-panel .admin-review-form {
+  flex: 1;
+}
+
 .layout {
   display: grid;
   grid-template-columns: 360px 1fr;
@@ -540,6 +601,23 @@ button:disabled { opacity: 0.5; cursor: not-allowed; }
   text-overflow: ellipsis;
   white-space: nowrap;
 }
+.program-tree-row .tree-label {
+  display: flex;
+  align-items: center;
+  gap: 0.45rem;
+}
+.program-tree-row .tree-label b {
+  display: grid;
+  place-items: center;
+  width: 1.15rem;
+  min-width: 1.15rem;
+  height: 1.15rem;
+  border-radius: 6px;
+  background: #e2e8f0;
+  color: #14213d;
+  font-size: 0.85rem;
+  line-height: 1;
+}
 .program-tree-row em,
 .program-tree-row strong,
 .review-pill {
@@ -578,13 +656,16 @@ button:disabled { opacity: 0.5; cursor: not-allowed; }
   padding: 0.65rem;
 }
 .program-node-preview {
-  height: min(42vh, 380px);
-  min-height: 280px;
+  position: relative;
+  width: 100%;
+  height: 340px;
+  min-height: 0;
   display: grid;
   place-items: center;
   border: 1px solid #e5e7eb;
   border-radius: 12px;
   background: white;
+  color: #14213d;
   overflow: hidden;
   padding: 0.75rem;
 }
@@ -595,6 +676,17 @@ button:disabled { opacity: 0.5; cursor: not-allowed; }
   object-fit: contain;
   display: block;
 }
+.program-node-preview span {
+  position: absolute;
+  right: 0.75rem;
+  bottom: 0.75rem;
+  border-radius: 999px;
+  background: rgba(20, 33, 61, 0.82);
+  color: white;
+  padding: 0.45rem 0.7rem;
+  font-size: 0.82rem;
+  font-weight: 800;
+}
 .admin-review-note p {
   margin: 0.35rem 0;
   line-height: 1.45;