diff --git a/frontend/src/components/Layout.jsx b/frontend/src/components/Layout.jsx
index b1c1cc3..39ea429 100644
--- a/frontend/src/components/Layout.jsx
+++ b/frontend/src/components/Layout.jsx
@@ -217,10 +217,22 @@ function IconPlusCircle() {
   );
 }
 
+const IconBurger = () => (
+  <svg width="28" height="28" viewBox="0 0 28 28" fill="none"
+    stroke="currentColor" strokeWidth="2" strokeLinecap="round"
+    aria-hidden="true">
+    <line x1="4" y1="8" x2="24" y2="8"/>
+    <line x1="4" y1="14" x2="24" y2="14"/>
+    <line x1="4" y1="20" x2="24" y2="20"/>
+  </svg>
+);
+
 export default function Layout() {
   const { sidebarCollapsed, setSidebarCollapsed, toggleSidebar, displayMode, setDisplayMode } = useUi();
   const navigate = useNavigate();
   const [navIcons, setNavIcons] = useState({});
+  const [burgerOpen, setBurgerOpen] = useState(false);
+  const burgerRef = useRef(null);
 
   // Auto-collapse en mode portrait sur tablette (768–1200px)
   useEffect(() => {
@@ -231,6 +243,16 @@ export default function Layout() {
     return () => mq.removeEventListener('change', handler);
   }, [setSidebarCollapsed]);
 
+  // Fermer le burger au clic extérieur
+  useEffect(() => {
+    if (!burgerOpen) return;
+    const handler = (e) => {
+      if (burgerRef.current && !burgerRef.current.contains(e.target)) setBurgerOpen(false);
+    };
+    document.addEventListener('mousedown', handler);
+    return () => document.removeEventListener('mousedown', handler);
+  }, [burgerOpen]);
+
   useEffect(() => {
     api.get('/icons').then(rows => {
       const m = {};
@@ -302,28 +324,55 @@ export default function Layout() {
         <div className="topbar topbar-global">
           <ProjectSearch />
           <div className="topbar-right">
-            <button
-              className="btn-add-invest"
-              onClick={() => navigate('/investissements?new=1')}
-            >
-              <IconPlusCircle />
-              Ajout Investissement
+            {/* Boutons visibles sur grand écran */}
+            <button className="btn-add-invest topbar-action-btn" onClick={() => navigate('/investissements?new=1')}>
+              <IconPlusCircle />Ajout Investissement
             </button>
-            <button
-              className="btn-add-invest"
-              onClick={() => navigate('/remboursements?new=1')}
-            >
-              <IconPlusCircle />
-              Nouveau remboursement
+            <button className="btn-add-invest topbar-action-btn" onClick={() => navigate('/remboursements?new=1')}>
+              <IconPlusCircle />Nouveau remboursement
             </button>
-            <button
-              className="btn-add-invest"
-              onClick={() => navigate('/depots-retraits?new=1')}
-            >
-              <IconPlusCircle />
-              Nouveau dépôt/retrait
+            <button className="btn-add-invest topbar-action-btn" onClick={() => navigate('/depots-retraits?new=1')}>
+              <IconPlusCircle />Nouveau dépôt/retrait
             </button>
 
+            {/* Bouton burger — visible sur tablette/mobile */}
+            <div className="topbar-burger-wrap" ref={burgerRef}>
+              <button
+                className="topbar-burger-btn"
+                onClick={() => setBurgerOpen(v => !v)}
+                aria-label="Menu actions"
+                aria-expanded={burgerOpen}
+              >
+                <IconBurger />
+              </button>
+              {burgerOpen && (
+                <div className="topbar-burger-menu">
+                  <button className="topbar-burger-search-item" onClick={() => { setBurgerOpen(false); document.querySelector('.project-search-input')?.focus(); }}>
+                    <svg width="15" height="15" viewBox="0 0 18 18" fill="none" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round" aria-hidden="true"><circle cx="7.5" cy="7.5" r="5.5"/><line x1="11.5" y1="11.5" x2="16" y2="16"/></svg>
+                    Rechercher un projet
+                  </button>
+                  <div className="topbar-burger-sep" />
+                  <button className="topbar-burger-item" onClick={() => { setBurgerOpen(false); navigate('/investissements?new=1'); }}>
+                    <IconPlusCircle />Ajout Investissement
+                  </button>
+                  <button className="topbar-burger-item" onClick={() => { setBurgerOpen(false); navigate('/remboursements?new=1'); }}>
+                    <IconPlusCircle />Nouveau remboursement
+                  </button>
+                  <button className="topbar-burger-item" onClick={() => { setBurgerOpen(false); navigate('/depots-retraits?new=1'); }}>
+                    <IconPlusCircle />Nouveau dépôt/retrait
+                  </button>
+                  <div className="topbar-burger-sep" />
+                  <div className="topbar-burger-toggle">
+                    <span className="topbar-burger-toggle-label">Affichage</span>
+                    <div className="display-toggle" role="group" aria-label="Mode d'affichage">
+                      <button className={`display-toggle-btn${displayMode === 'brut' ? ' active' : ''}`} onClick={() => setDisplayMode('brut')} aria-pressed={displayMode === 'brut'}>Brut</button>
+                      <button className={`display-toggle-btn${displayMode === 'net' ? ' active' : ''}`} onClick={() => setDisplayMode('net')} aria-pressed={displayMode === 'net'}>Net</button>
+                    </div>
+                  </div>
+                </div>
+              )}
+            </div>
+
             <div className="display-toggle" role="group" aria-label="Mode d'affichage">
               <button
                 className={`display-toggle-btn${displayMode === 'brut' ? ' active' : ''}`}
diff --git a/frontend/src/styles.css b/frontend/src/styles.css
index 81e996c..02bcb2d 100644
--- a/frontend/src/styles.css
+++ b/frontend/src/styles.css
@@ -240,6 +240,69 @@ a { color: var(--primary); }
 }
 .btn-add-invest:hover { background: var(--primary-hover); box-shadow: 0 3px 12px rgba(59,130,246,.5); }
 
+/* ── Burger menu topbar ──────────────────────────────────────── */
+.topbar-burger-wrap { position: relative; display: none; }
+.topbar-burger-btn {
+  display: flex; align-items: center; justify-content: center;
+  padding: 0; background: none; border: none;
+  cursor: pointer; color: var(--text);
+  transition: color .15s;
+}
+.topbar-burger-btn:hover { color: var(--primary); }
+.topbar-burger-menu {
+  position: absolute; top: calc(100% + 8px); right: 0;
+  background: var(--surface); border: 1px solid var(--border);
+  border-radius: 10px; box-shadow: 0 8px 24px rgba(0,0,0,.10);
+  min-width: 220px; z-index: 200; padding: 6px;
+  display: flex; flex-direction: column; gap: 2px;
+}
+.topbar-burger-item {
+  display: flex; align-items: center; gap: 8px;
+  padding: 9px 12px; border: none; border-radius: 6px;
+  background: none; color: var(--text); font-size: var(--fs-base);
+  font-weight: 600; cursor: pointer; text-align: left; width: 100%;
+  transition: background .12s;
+}
+.topbar-burger-item:hover { background: var(--surface-2); }
+.topbar-burger-item svg { color: var(--primary); flex-shrink: 0; }
+.topbar-burger-search-item {
+  display: flex; align-items: center; gap: 8px;
+  padding: 9px 12px; border: none; border-radius: 6px;
+  background: none; color: var(--text-muted); font-size: var(--fs-sm);
+  cursor: pointer; text-align: left; width: 100%;
+  transition: background .12s;
+}
+.topbar-burger-search-item:hover { background: var(--surface-2); }
+.topbar-burger-sep { height: 1px; background: var(--border); margin: 2px 0; }
+
+/* Bloc toggle dans le burger */
+.topbar-burger-toggle {
+  display: flex; align-items: center; justify-content: space-between;
+  padding: 6px 12px 4px;
+}
+.topbar-burger-toggle-label {
+  font-size: var(--fs-sm); color: var(--text-muted);
+}
+
+/* Tablette : masquer les boutons texte et le toggle, afficher le burger */
+@media (max-width: 1100px) {
+  .topbar-action-btn { display: none !important; }
+  .topbar-burger-wrap { display: block; }
+  .topbar-global .topbar-right > .display-toggle { display: none; }
+}
+
+/* Mobile : masquer aussi la barre de recherche dans la topbar */
+@media (max-width: 640px) {
+  .topbar-global .project-search-wrap { display: none; }
+  .topbar-burger-search-item { display: flex; }
+}
+
+/* Sur tablette, masquer l'item recherche dans le burger (search reste visible) */
+@media (min-width: 641px) and (max-width: 1100px) {
+  .topbar-burger-search-item,
+  .topbar-burger-search-item + .topbar-burger-sep { display: none; }
+}
+
 /* btn-icon — bouton icône discret (cercle hover) */
 .btn-icon {
   display: flex; align-items: center; justify-content: center;