diff --git a/static/app.js b/static/app.js
index c28541a..e689a4e 100644
--- a/static/app.js
+++ b/static/app.js
@@ -149,8 +149,9 @@ async function saveTool() {
 async function openToolDetail(id) {
   const t = await api.get(`/api/tools/${id}`);
   const rents = await api.get(`/api/rentals?tool_id=${id}`);
-  const gallery = t.images.length ? t.images.map(img =>
-    `<img src="/uploads/tools/${img.filename}" class="${img.is_main?'main-img':''}" title="${img.is_main?'Principale':''}" onclick="setMainImage(${id},${img.id})"/>`
+  const imgUrls = t.images.map(img => `/uploads/tools/${img.filename}`);
+  const gallery = t.images.length ? t.images.map((img, idx) =>
+    `<img src="/uploads/tools/${img.filename}" class="${img.is_main?'main-img':''}" title="Cliquer pour agrandir" onclick="openLightbox(${JSON.stringify(imgUrls).replace(/"/g,'&quot;')}, ${idx})"/>`
   ).join('') : '<span style="color:var(--muted)">Aucune photo</span>';
 
   document.getElementById('tool-detail-content').innerHTML = `
@@ -509,5 +510,44 @@ function statusLabel(s) {
   return {confirmed:'Confirmée', ongoing:'En cours', returned:'Retournée', cancelled:'Annulée'}[s] || s;
 }
 
+// ─── Lightbox ───────────────────────────────────────────────────────────────
+let _lbImages = [], _lbIdx = 0;
+
+function openLightbox(images, idx) {
+  _lbImages = images;
+  _lbIdx = idx;
+  _lbRender();
+  document.getElementById('lightbox').classList.remove('hidden');
+  document.addEventListener('keydown', _lbKey);
+}
+
+function closeLightbox() {
+  document.getElementById('lightbox').classList.add('hidden');
+  document.removeEventListener('keydown', _lbKey);
+}
+
+function lightboxNav(dir) {
+  _lbIdx = (_lbIdx + dir + _lbImages.length) % _lbImages.length;
+  _lbRender();
+}
+
+function _lbRender() {
+  const url = _lbImages[_lbIdx];
+  const img = document.getElementById('lightbox-img');
+  img.src = url;
+  document.getElementById('lightbox-counter').textContent = `${_lbIdx + 1} / ${_lbImages.length}`;
+  const dl = document.getElementById('lightbox-download');
+  dl.href = url;
+  dl.download = url.split('/').pop();
+  document.querySelector('.lightbox-prev').style.display = _lbImages.length > 1 ? '' : 'none';
+  document.querySelector('.lightbox-next').style.display = _lbImages.length > 1 ? '' : 'none';
+}
+
+function _lbKey(e) {
+  if (e.key === 'ArrowLeft') lightboxNav(-1);
+  else if (e.key === 'ArrowRight') lightboxNav(1);
+  else if (e.key === 'Escape') closeLightbox();
+}
+
 // ─── Init ───────────────────────────────────────────────────────────────────
 loadDashboard();
diff --git a/static/style.css b/static/style.css
index 8193236..cee7474 100644
--- a/static/style.css
+++ b/static/style.css
@@ -180,3 +180,22 @@ input[type="file"] { padding: 6px; font-size: 0.8rem; }
   .nav-item { white-space: nowrap; }
   .logo { display: none; }
 }
+
+/* Lightbox */
+.lightbox { position: fixed; inset: 0; z-index: 200; display: flex; align-items: center; justify-content: center; }
+.lightbox.hidden { display: none; }
+.lightbox-overlay { position: absolute; inset: 0; background: rgba(0,0,0,0.92); }
+.lightbox-content { position: relative; z-index: 1; display: flex; flex-direction: column; align-items: center; max-width: 90vw; max-height: 90vh; gap: 12px; }
+.lightbox-content img { max-width: 85vw; max-height: 80vh; object-fit: contain; border-radius: 8px; display: block; }
+.lightbox-close { position: fixed; top: 16px; right: 20px; background: rgba(255,255,255,0.1); border: none; color: #fff; font-size: 1.4rem; cursor: pointer; border-radius: 50%; width: 36px; height: 36px; display: flex; align-items: center; justify-content: center; }
+.lightbox-close:hover { background: rgba(255,255,255,0.25); }
+.lightbox-nav { position: fixed; top: 50%; transform: translateY(-50%); background: rgba(255,255,255,0.1); border: none; color: #fff; font-size: 2.5rem; cursor: pointer; padding: 12px 16px; border-radius: 8px; line-height: 1; }
+.lightbox-nav:hover { background: rgba(255,255,255,0.25); }
+.lightbox-prev { left: 12px; }
+.lightbox-next { right: 12px; }
+.lightbox-footer { display: flex; align-items: center; gap: 16px; }
+.lightbox-footer #lightbox-counter { color: rgba(255,255,255,0.6); font-size: 0.85rem; }
+
+/* Tool gallery — images cliquables */
+.tool-detail-gallery img { cursor: zoom-in; transition: opacity 0.15s; }
+.tool-detail-gallery img:hover { opacity: 0.85; }
diff --git a/templates/index.html b/templates/index.html
index 2dd7fce..efc13a8 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -216,6 +216,21 @@
   </div>
 </div>
 
+<!-- LIGHTBOX -->
+<div id="lightbox" class="lightbox hidden">
+  <div class="lightbox-overlay" onclick="closeLightbox()"></div>
+  <div class="lightbox-content">
+    <button class="lightbox-close" onclick="closeLightbox()">✕</button>
+    <button class="lightbox-nav lightbox-prev" onclick="lightboxNav(-1)">‹</button>
+    <img id="lightbox-img" src="" alt=""/>
+    <button class="lightbox-nav lightbox-next" onclick="lightboxNav(1)">›</button>
+    <div class="lightbox-footer">
+      <span id="lightbox-counter"></span>
+      <a id="lightbox-download" href="" download class="btn btn-primary btn-sm">⬇ Télécharger</a>
+    </div>
+  </div>
+</div>
+
 <script src="/static/app.js"></script>
 </body>
 </html>