diff --git a/frontend/index.html b/frontend/index.html
index ee0681b..2636ad6 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -1315,7 +1315,7 @@
 
                 <!-- Right Sidebar (Outline/TOC) -->
                 <aside
-                    class="right-sidebar"
+                    class="right-sidebar hidden"
                     id="right-sidebar"
                     role="complementary"
                     aria-label="Table des matières"
diff --git a/frontend/js/state.js b/frontend/js/state.js
index 9d870de..f09ef26 100644
--- a/frontend/js/state.js
+++ b/frontend/js/state.js
@@ -48,7 +48,7 @@ export const state = {
   outlineObserver: null,
   activeHeadingId: null,
   headingsCache: [],
-  rightSidebarVisible: true,
+  rightSidebarVisible: false,
   rightSidebarWidth: 280,
 
   // Sidebar
diff --git a/frontend/js/ui.js b/frontend/js/ui.js
index 9ac2cf7..241ab90 100644
--- a/frontend/js/ui.js
+++ b/frontend/js/ui.js
@@ -20,12 +20,12 @@ export const RightSidebarManager = {
   },
 
   loadState() {
-    const savedVisible = localStorage.getItem("obsigate-right-sidebar-visible");
     const savedWidth = localStorage.getItem("obsigate-right-sidebar-width");
 
-    if (savedVisible !== null) {
-      state.rightSidebarVisible = savedVisible === "true";
-    }
+    // Le panneau TOC (« Sur cette page ») part toujours ferme a l'ouverture
+    // de l'app ; seul le bouton TOC/toggle du panneau l'ouvre. La largeur,
+    // elle, est memorisee.
+    state.rightSidebarVisible = false;
 
     if (savedWidth) {
       state.rightSidebarWidth = parseInt(savedWidth) || 280;
diff --git a/frontend/popout.html b/frontend/popout.html
index eee71da..f87e5fa 100644
--- a/frontend/popout.html
+++ b/frontend/popout.html
@@ -557,12 +557,10 @@ const RightSidebarManager = {
     },
 
     loadState() {
-      const savedVisible = localStorage.getItem('obsigate-right-sidebar-visible');
+      // Panneau TOC toujours ferme a l'ouverture ; seul le bouton l'ouvre.
       const savedWidth = localStorage.getItem('obsigate-right-sidebar-width');
 
-      if (savedVisible !== null) {
-        rightSidebarVisible = savedVisible === 'true';
-      }
+      rightSidebarVisible = false;
 
       if (savedWidth) {
         rightSidebarWidth = parseInt(savedWidth) || 280;