diff --git a/backend/api/admin_gallery_api.py b/backend/api/admin_gallery_api.py
index 127b30d..96f2179 100644
--- a/backend/api/admin_gallery_api.py
+++ b/backend/api/admin_gallery_api.py
@@ -66,15 +66,26 @@ async def admin_get_photos(
     photos = [p for p in all_photos if _is_image(p)]
 
     # Enrichit chaque photo avec mtime depuis le disque
+    # Indexe par stem ET par nom complet pour couvrir les deux formats d'id
     mtime_index: dict[str, float] = {}
-    if media_dir.exists():
-        for f in media_dir.iterdir():
-            mtime_index[f.stem] = f.stat().st_mtime
+    for media_dir_candidate in [
+        media_dir,
+        Path("/home/pi/photobooth-data/media/processed_full"),
+        Path("/home/pi/photobooth-data/media"),
+    ]:
+        if media_dir_candidate.exists():
+            for f in media_dir_candidate.iterdir():
+                if f.is_file():
+                    mt = f.stat().st_mtime
+                    mtime_index[f.name] = mt   # uuid.jpg
+                    mtime_index[f.stem] = mt   # uuid
+            break
 
     for p in photos:
         pid = _get_id(p)
         p["photo_id"] = pid
-        mt = mtime_index.get(pid, 0.0)
+        stem = pid.rsplit(".", 1)[0] if "." in pid else pid
+        mt = mtime_index.get(pid) or mtime_index.get(stem) or 0.0
         p["mtime"] = mt
         p["date_iso"] = datetime.fromtimestamp(mt).strftime("%Y-%m-%d") if mt else ""
         p["date_label"] = datetime.fromtimestamp(mt).strftime("%d/%m/%Y %H:%M") if mt else ""
diff --git a/frontend/templates/admin/gallery.html b/frontend/templates/admin/gallery.html
index 4406251..9198aa6 100644
--- a/frontend/templates/admin/gallery.html
+++ b/frontend/templates/admin/gallery.html
@@ -106,16 +106,31 @@
   display: none; position: fixed; inset: 0; z-index: 1000;
   background: rgba(0,0,0,.92); backdrop-filter: blur(8px);
   align-items: center; justify-content: center; padding: 1.5rem;
+  gap: 1rem;
 }
 .lightbox.open { display: flex; }
 
+.lb-nav-btn {
+  flex-shrink: 0; width: 44px; height: 44px; border-radius: 50%;
+  border: 1px solid rgba(255,255,255,.2); background: rgba(255,255,255,.08);
+  color: #fff; font-size: 1.3rem; cursor: pointer; display: flex;
+  align-items: center; justify-content: center; transition: background .15s;
+  user-select: none;
+}
+.lb-nav-btn:hover:not(:disabled) { background: rgba(255,255,255,.18); }
+.lb-nav-btn:disabled { opacity: .2; cursor: default; }
+
 .lb-modal {
   background: var(--surface); border: 1px solid var(--border);
   border-radius: 16px; overflow: hidden;
-  max-width: min(900px, 95vw); width: 100%;
+  max-width: min(860px, calc(95vw - 110px)); width: 100%;
   display: flex; flex-direction: column; max-height: 95vh;
 }
 
+.lb-counter {
+  font-size: .75rem; color: var(--text-muted); white-space: nowrap;
+}
+
 .lb-header {
   display: flex; align-items: center; justify-content: space-between;
   padding: .75rem 1.1rem; border-bottom: 1px solid var(--border);
@@ -247,6 +262,7 @@
 
 <!-- ── Lightbox ─────────────────────────────────────────────────────────────── -->
 <div class="lightbox" id="lightbox" onclick="lbBackdropClose(event)">
+  <button class="lb-nav-btn" id="lb-prev" onclick="lbNavigate(-1);event.stopPropagation()">‹</button>
   <div class="lb-modal">
 
     <!-- En-tête -->
@@ -255,6 +271,7 @@
         <div class="lb-date" id="lb-date">—</div>
         <div class="lb-id" id="lb-id"></div>
       </div>
+      <span class="lb-counter" id="lb-counter"></span>
       <button class="lb-close-btn" onclick="closeLightbox()">✕</button>
     </div>
 
@@ -294,6 +311,7 @@
     </div>
 
   </div>
+  <button class="lb-nav-btn" id="lb-next" onclick="lbNavigate(1);event.stopPropagation()">›</button>
 </div>
 {% endblock %}
 
@@ -302,6 +320,8 @@
 let currentPage  = 1;
 let totalPages   = 1;
 let allPhotos    = [];
+let displayedPhotos  = [];   // photos actuellement dans la grille (après filtre statut)
+let currentIndex     = -1;   // index dans displayedPhotos
 let currentPhotoId   = null;
 let currentPhotoData = null;
 
@@ -411,15 +431,17 @@ function updateFilterSummary(total) {
 // Rendu grille
 // ════════════════════════════════════════════════════════════════════════════
 function renderGrid(photos) {
+  displayedPhotos = photos || [];
   const grid = document.getElementById('photo-grid');
 
-  if (!photos || !photos.length) {
+  if (!displayedPhotos.length) {
     grid.innerHTML = `<div style="color:var(--text-muted);grid-column:1/-1;text-align:center;padding:2rem">
       📷 Aucune photo pour ces filtres</div>`;
     return;
   }
 
-  grid.innerHTML = photos.map(p => {
+  // On utilise l'index (pas le JSON sérialisé) pour éviter les problèmes de quotes
+  grid.innerHTML = displayedPhotos.map((p, idx) => {
     const pid = p.photo_id || p.id || '';
     const hasPending  = p.print_pending > 0;
     const hasPrinting = p.print_printing > 0;
@@ -433,7 +455,7 @@ function renderGrid(photos) {
 
     return `
       <div class="photo-card ${hasPending || hasPrinting ? 'has-print' : ''}" id="card-${pid}"
-           onclick="openLightbox(${JSON.stringify(p).replace(/'/g, '&#39;')})">
+           onclick="openLightboxIdx(${idx})">
         <img src="${p.thumb_url}" loading="lazy" alt="">
         ${badge}${dateLabel}
         <div class="card-overlay">
@@ -450,19 +472,31 @@ function renderGrid(photos) {
 // ════════════════════════════════════════════════════════════════════════════
 // Lightbox
 // ════════════════════════════════════════════════════════════════════════════
-function openLightbox(photo) {
+function openLightboxIdx(idx) {
+  if (idx < 0 || idx >= displayedPhotos.length) return;
+  currentIndex     = idx;
+  const photo      = displayedPhotos[idx];
   currentPhotoData = photo;
   currentPhotoId   = photo.photo_id || photo.id || '';
 
-  document.getElementById('lb-img').src  = photo.full_url || photo.thumb_url;
-  document.getElementById('lb-date').textContent = photo.date_label || '—';
-  document.getElementById('lb-id').textContent   = currentPhotoId;
-  document.getElementById('lb-btn-dl').href = photo.download_url || photo.full_url;
+  document.getElementById('lb-img').src             = photo.full_url || photo.thumb_url;
+  document.getElementById('lb-date').textContent    = photo.date_label || '—';
+  document.getElementById('lb-id').textContent      = currentPhotoId;
+  document.getElementById('lb-btn-dl').href         = photo.download_url || photo.full_url;
+  document.getElementById('lb-counter').textContent = `${idx + 1} / ${displayedPhotos.length}`;
+
+  // Boutons nav
+  document.getElementById('lb-prev').disabled = idx <= 0;
+  document.getElementById('lb-next').disabled = idx >= displayedPhotos.length - 1;
 
   _updateLbPrintPanel(photo);
   document.getElementById('lightbox').classList.add('open');
 }
 
+function lbNavigate(dir) {
+  openLightboxIdx(currentIndex + dir);
+}
+
 function _updateLbPrintPanel(photo) {
   const panel    = document.getElementById('lb-print-panel');
   const list     = document.getElementById('lb-queue-list');
@@ -496,12 +530,31 @@ function closeLightbox() {
   document.getElementById('lightbox').classList.remove('open');
   document.getElementById('lb-img').src = '';
   currentPhotoId = currentPhotoData = null;
+  currentIndex = -1;
 }
 
 function lbBackdropClose(e) {
   if (e.target === document.getElementById('lightbox')) closeLightbox();
 }
-document.addEventListener('keydown', e => { if (e.key === 'Escape') closeLightbox(); });
+
+// Clavier : Échap + flèches
+document.addEventListener('keydown', e => {
+  const lb = document.getElementById('lightbox');
+  if (!lb.classList.contains('open')) return;
+  if (e.key === 'Escape')      { closeLightbox(); }
+  else if (e.key === 'ArrowLeft')  { lbNavigate(-1); }
+  else if (e.key === 'ArrowRight') { lbNavigate(1); }
+});
+
+// Swipe tactile
+let _touchX = 0;
+document.getElementById('lightbox').addEventListener('touchstart', e => {
+  _touchX = e.touches[0].clientX;
+}, { passive: true });
+document.getElementById('lightbox').addEventListener('touchend', e => {
+  const dx = e.changedTouches[0].clientX - _touchX;
+  if (Math.abs(dx) > 50) lbNavigate(dx < 0 ? 1 : -1);
+}, { passive: true });
 
 // ════════════════════════════════════════════════════════════════════════════
 // Actions impression
@@ -586,15 +639,23 @@ async function _refreshPhotoData(pid) {
   try {
     const data = await api('GET', `/admin/api/gallery/photos?${_buildParams(currentPage)}`);
     allPhotos = data.photos || [];
-    const photo = allPhotos.find(p => (p.photo_id || p.id) === pid);
-    if (photo && currentPhotoId === pid) {
-      currentPhotoData = photo;
-      _updateLbPrintPanel(photo);
-    }
     let photos = allPhotos;
     if (statusFilter === 'pending') photos = allPhotos.filter(p => p.print_pending > 0 || p.print_printing > 0);
     renderGrid(photos);
     document.getElementById('pending-count').textContent = allPhotos.filter(p => p.print_pending > 0).length;
+
+    // Si lightbox ouverte sur cette photo, mettre à jour le panel impression
+    if (currentPhotoId === pid) {
+      const newIdx = displayedPhotos.findIndex(p => (p.photo_id || p.id) === pid);
+      if (newIdx >= 0) {
+        currentIndex = newIdx;
+        currentPhotoData = displayedPhotos[newIdx];
+        _updateLbPrintPanel(currentPhotoData);
+        document.getElementById('lb-prev').disabled = newIdx <= 0;
+        document.getElementById('lb-next').disabled = newIdx >= displayedPhotos.length - 1;
+        document.getElementById('lb-counter').textContent = `${newIdx + 1} / ${displayedPhotos.length}`;
+      }
+    }
   } catch(e) {}
 }