diff --git a/frontend/app.js b/frontend/app.js
index 89ec9ae..8ff8729 100644
--- a/frontend/app.js
+++ b/frontend/app.js
@@ -94,9 +94,15 @@
     document.documentElement.setAttribute("data-theme", theme);
     localStorage.setItem("obsigate-theme", theme);
 
-    const icon = document.getElementById("theme-icon");
-    if (icon) {
-      icon.setAttribute("data-lucide", theme === "dark" ? "moon" : "sun");
+    // Update theme button icon and label
+    const themeBtn = document.getElementById("theme-toggle");
+    const themeLabel = document.getElementById("theme-label");
+    if (themeBtn && themeLabel) {
+      const icon = themeBtn.querySelector("i");
+      if (icon) {
+        icon.setAttribute("data-lucide", theme === "dark" ? "moon" : "sun");
+      }
+      themeLabel.textContent = theme === "dark" ? "Sombre" : "Clair";
       safeCreateIcons();
     }
 
@@ -114,6 +120,32 @@
     applyTheme(current === "dark" ? "light" : "dark");
   }
 
+  function initHeaderMenu() {
+    const menuBtn = document.getElementById("header-menu-btn");
+    const menuDropdown = document.getElementById("header-menu-dropdown");
+
+    if (!menuBtn || !menuDropdown) return;
+
+    menuBtn.addEventListener("click", (e) => {
+      e.stopPropagation();
+      menuBtn.classList.toggle("active");
+      menuDropdown.classList.toggle("active");
+    });
+
+    // Close menu when clicking outside
+    document.addEventListener("click", (e) => {
+      if (!menuDropdown.contains(e.target) && e.target !== menuBtn) {
+        menuBtn.classList.remove("active");
+        menuDropdown.classList.remove("active");
+      }
+    });
+
+    // Prevent menu from closing when clicking inside
+    menuDropdown.addEventListener("click", (e) => {
+      e.stopPropagation();
+    });
+  }
+
   // ---------------------------------------------------------------------------
   // API helpers
   // ---------------------------------------------------------------------------
@@ -948,6 +980,7 @@
   // ---------------------------------------------------------------------------
   async function init() {
     initTheme();
+    initHeaderMenu();
     document.getElementById("theme-toggle").addEventListener("click", toggleTheme);
     document.getElementById("header-logo").addEventListener("click", goHome);
     initSearch();
diff --git a/frontend/index.html b/frontend/index.html
index 208e8bb..cc678bc 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -12,11 +12,43 @@
   
   <!-- CodeMirror 6 -->
   <script type="module">
-    import { EditorView, basicSetup } from "https://esm.sh/@codemirror/basic-setup@0.20.0";
+    import { EditorView, keymap, lineNumbers, highlightActiveLineGutter, highlightSpecialChars, drawSelection, dropCursor, rectangularSelection, crosshairCursor, highlightActiveLine } from "https://esm.sh/@codemirror/view@6.9.0";
     import { EditorState } from "https://esm.sh/@codemirror/state@6.2.0";
+    import { defaultHighlightStyle, syntaxHighlighting, indentOnInput, bracketMatching, foldGutter, foldKeymap } from "https://esm.sh/@codemirror/language@6.6.0";
+    import { defaultKeymap, history, historyKeymap } from "https://esm.sh/@codemirror/commands@6.2.3";
+    import { searchKeymap, highlightSelectionMatches } from "https://esm.sh/@codemirror/search@6.3.0";
+    import { autocompletion, completionKeymap, closeBrackets, closeBracketsKeymap } from "https://esm.sh/@codemirror/autocomplete@6.5.0";
     import { markdown } from "https://esm.sh/@codemirror/lang-markdown@6.1.0";
     import { oneDark } from "https://esm.sh/@codemirror/theme-one-dark@6.1.0";
-    import { keymap } from "https://esm.sh/@codemirror/view@6.9.0";
+    
+    const basicSetup = [
+      lineNumbers(),
+      highlightActiveLineGutter(),
+      highlightSpecialChars(),
+      history(),
+      foldGutter(),
+      drawSelection(),
+      dropCursor(),
+      EditorState.allowMultipleSelections.of(true),
+      indentOnInput(),
+      syntaxHighlighting(defaultHighlightStyle, { fallback: true }),
+      bracketMatching(),
+      closeBrackets(),
+      autocompletion(),
+      rectangularSelection(),
+      crosshairCursor(),
+      highlightActiveLine(),
+      highlightSelectionMatches(),
+      keymap.of([
+        ...closeBracketsKeymap,
+        ...defaultKeymap,
+        ...searchKeymap,
+        ...historyKeymap,
+        ...foldKeymap,
+        ...completionKeymap,
+      ])
+    ];
+    
     window.CodeMirror = { EditorView, EditorState, basicSetup, markdown, oneDark, keymap };
   </script>
 </head>
@@ -39,13 +71,27 @@
         <input type="text" id="search-input" placeholder="Recherche..." autocomplete="off">
       </div>
 
-      <select id="vault-filter" class="search-vault-filter">
-        <option value="all">Toutes les vaults</option>
-      </select>
-
-      <button class="theme-toggle" id="theme-toggle" title="Changer le thème">
-        <i data-lucide="moon" id="theme-icon" style="width:18px;height:18px"></i>
-      </button>
+      <div class="header-menu">
+        <button class="header-menu-btn" id="header-menu-btn" title="Options">
+          <i data-lucide="settings" style="width:18px;height:18px"></i>
+        </button>
+        <div class="header-menu-dropdown" id="header-menu-dropdown">
+          <div class="menu-section">
+            <div class="menu-label">Vault</div>
+            <select id="vault-filter" class="menu-select">
+              <option value="all">Tous les vaults</option>
+            </select>
+          </div>
+          <div class="menu-divider"></div>
+          <div class="menu-section">
+            <div class="menu-label">Thème</div>
+            <button class="menu-theme-btn" id="theme-toggle">
+              <i data-lucide="sun" style="width:16px;height:16px"></i>
+              <span id="theme-label">Clair</span>
+            </button>
+          </div>
+        </div>
+      </div>
     </header>
 
     <!-- Main -->
diff --git a/frontend/style.css b/frontend/style.css
index 71a9c55..1aeb43c 100644
--- a/frontend/style.css
+++ b/frontend/style.css
@@ -157,19 +157,11 @@ a:hover {
   pointer-events: none;
 }
 
-.search-vault-filter {
-  padding: 6px 10px;
-  border: 1px solid var(--border);
-  border-radius: 8px;
-  background: var(--search-bg);
-  color: var(--text-primary);
-  font-family: 'JetBrains Mono', monospace;
-  font-size: 0.8rem;
-  outline: none;
-  cursor: pointer;
+.header-menu {
+  position: relative;
 }
 
-.theme-toggle {
+.header-menu-btn {
   background: none;
   border: 1px solid var(--border);
   border-radius: 8px;
@@ -180,10 +172,90 @@ a:hover {
   align-items: center;
   transition: color 200ms ease, border-color 200ms ease;
 }
-.theme-toggle:hover {
+.header-menu-btn:hover {
   color: var(--accent);
   border-color: var(--accent);
 }
+.header-menu-btn.active {
+  color: var(--accent);
+  border-color: var(--accent);
+  background: var(--tag-bg);
+}
+
+.header-menu-dropdown {
+  display: none;
+  position: absolute;
+  top: calc(100% + 8px);
+  right: 0;
+  background: var(--bg-secondary);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  box-shadow: 0 4px 16px rgba(0,0,0,0.3);
+  min-width: 220px;
+  z-index: 100;
+  padding: 8px;
+}
+.header-menu-dropdown.active {
+  display: block;
+}
+
+.menu-section {
+  padding: 8px;
+}
+
+.menu-label {
+  font-family: 'JetBrains Mono', monospace;
+  font-size: 0.7rem;
+  color: var(--text-muted);
+  text-transform: uppercase;
+  letter-spacing: 0.5px;
+  margin-bottom: 6px;
+  font-weight: 600;
+}
+
+.menu-select {
+  width: 100%;
+  padding: 6px 10px;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  background: var(--search-bg);
+  color: var(--text-primary);
+  font-family: 'JetBrains Mono', monospace;
+  font-size: 0.8rem;
+  outline: none;
+  cursor: pointer;
+  transition: border-color 200ms ease;
+}
+.menu-select:hover, .menu-select:focus {
+  border-color: var(--accent);
+}
+
+.menu-divider {
+  height: 1px;
+  background: var(--border);
+  margin: 4px 0;
+}
+
+.menu-theme-btn {
+  width: 100%;
+  background: none;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  padding: 8px 12px;
+  cursor: pointer;
+  color: var(--text-primary);
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  font-family: 'JetBrains Mono', monospace;
+  font-size: 0.8rem;
+  transition: all 200ms ease;
+}
+.menu-theme-btn:hover {
+  background: var(--bg-hover);
+  border-color: var(--accent);
+  color: var(--accent);
+}
 
 /* --- Main body --- */
 .main-body {
@@ -938,9 +1010,13 @@ body.resizing-v {
     font-size: 0.8rem;
   }
 
-  .search-vault-filter {
-    font-size: 0.7rem;
-    padding: 4px 6px;
+  .header-menu-btn {
+    padding: 5px 8px;
+  }
+
+  .header-menu-dropdown {
+    right: -8px;
+    min-width: 200px;
   }
 
   .sidebar {