diff --git a/frontend-v2/src/lib/components/layout/AppShell.svelte b/frontend-v2/src/lib/components/layout/AppShell.svelte
index b8b02fe..b17163f 100644
--- a/frontend-v2/src/lib/components/layout/AppShell.svelte
+++ b/frontend-v2/src/lib/components/layout/AppShell.svelte
@@ -112,36 +112,6 @@
 						<item.icon size={16} strokeWidth={1.8} />
 						<span>{item.label}</span>
 					</a>
-					{#if item.id === 'brain' && brainExpanded}
-						<div class="rail-sub">
-							<div class="rail-sub-tabs">
-								<button class="rail-sub-tab" class:active={brainSubView === 'folders'} onclick={() => brainSubView = 'folders'}>
-									<FolderOpen size={11} strokeWidth={2} /> Folders
-								</button>
-								<button class="rail-sub-tab" class:active={brainSubView === 'tags'} onclick={() => brainSubView = 'tags'}>
-									<Tag size={11} strokeWidth={2} /> Tags
-								</button>
-							</div>
-							{#if brainSubView === 'folders'}
-								<a href="/brain" class="rail-sub-item" class:active={page.url.pathname === '/brain' && !page.url.searchParams.get('folder')}>
-									<span>All</span>
-								</a>
-								{#each brainFolders as folder}
-									<a href="/brain?folder={folder.name}" class="rail-sub-item" class:active={page.url.searchParams.get('folder') === folder.name}>
-										<span>{folder.name}</span>
-										<span class="rail-sub-count">{folder.item_count}</span>
-									</a>
-								{/each}
-							{:else}
-								{#each brainTags as tag}
-									<a href="/brain?tag={tag.name}" class="rail-sub-item" class:active={page.url.searchParams.get('tag') === tag.name}>
-										<span>{tag.name}</span>
-										<span class="rail-sub-count">{tag.item_count}</span>
-									</a>
-								{/each}
-							{/if}
-						</div>
-					{/if}
 				{/each}
 			</nav>
 		</div>
diff --git a/frontend-v2/src/lib/pages/brain/AtelierBrainPage.svelte b/frontend-v2/src/lib/pages/brain/AtelierBrainPage.svelte
index 2ec925a..8e8795f 100644
--- a/frontend-v2/src/lib/pages/brain/AtelierBrainPage.svelte
+++ b/frontend-v2/src/lib/pages/brain/AtelierBrainPage.svelte
@@ -367,10 +367,49 @@
     </section>
 
     <!-- ═══ Sidebar + Main layout ═══ -->
-    <!-- Main content -->
-    <div>
-      <!-- Active filter indicator -->
-      {#if activeFolder || activeTag}
+    <div class="brain-layout">
+
+      <!-- Second sidebar (like Reader) -->
+      <aside class="brain-sidebar">
+        <div class="sidebar-header">
+          <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round"><path d="M12 2L2 7l10 5 10-5-10-5z"/><path d="M2 17l10 5 10-5"/><path d="M2 12l10 5 10-5"/></svg>
+          <span class="sidebar-title">Brain</span>
+        </div>
+
+        <nav class="sidebar-nav">
+          <button class="nav-item" class:active={!activeFolder && !activeTag} onclick={() => { activeFolder = null; activeTag = null; activeFolderId = null; activeTagId = null; loadItems(); }}>
+            <span class="nav-label">All items</span>
+            <span class="nav-count">{total}</span>
+          </button>
+        </nav>
+
+        <div class="sidebar-separator"></div>
+        <div class="sidebar-section-label">Folders</div>
+        <nav class="sidebar-nav">
+          {#each sidebarFolders.filter(f => f.is_active) as folder}
+            <button class="nav-item" class:active={activeFolder === folder.name} onclick={() => { activeFolder = folder.name; activeFolderId = folder.id; activeTag = null; activeTagId = null; loadItems(); }}>
+              <span class="nav-label">{folder.name}</span>
+              {#if folder.item_count > 0}<span class="nav-count">{folder.item_count}</span>{/if}
+            </button>
+          {/each}
+        </nav>
+
+        <div class="sidebar-separator"></div>
+        <div class="sidebar-section-label">Tags</div>
+        <nav class="sidebar-nav">
+          {#each sidebarTags.filter(t => t.is_active && t.item_count > 0) as tag}
+            <button class="nav-item" class:active={activeTag === tag.name} onclick={() => { activeTag = tag.name; activeTagId = tag.id; activeFolder = null; activeFolderId = null; loadItems(); }}>
+              <span class="nav-label">{tag.name}</span>
+              <span class="nav-count">{tag.item_count}</span>
+            </button>
+          {/each}
+        </nav>
+      </aside>
+
+      <!-- Main content -->
+      <div class="brain-content">
+        <!-- Active filter indicator -->
+        {#if activeFolder || activeTag}
         <div class="active-filter">
           <span class="filter-label">Filtered by {activeFolder ? 'folder' : 'tag'}:</span>
           <span class="filter-tag">{activeFolder || activeTag}</span>
@@ -479,7 +518,8 @@
       </div>
     {/if}
 
-    </div><!-- main content -->
+      </div><!-- .brain-content -->
+    </div><!-- .brain-layout -->
 
   </div>
 </div>
@@ -703,44 +743,50 @@
   }
   .capture-btn:hover { opacity: 0.9; }
 
-  /* ═══ Layout: Sidebar + Main ═══ */
-  .brain-layout { display: grid; grid-template-columns: 240px 1fr; gap: 16px; align-items: start; }
+  /* ═══ Layout: Sidebar + Content (Reader pattern) ═══ */
+  .brain-layout {
+    display: flex;
+    min-height: calc(100vh - 60px);
+    margin: 0 -24px;
+  }
 
   .brain-sidebar {
-    position: sticky; top: 68px;
-    border-radius: 20px; border: 1px solid rgba(35,26,17,0.08);
-    background: rgba(255,252,248,0.72); backdrop-filter: blur(14px);
-    padding: 14px; max-height: calc(100vh - 80px); overflow-y: auto;
+    width: 248px;
+    flex-shrink: 0;
+    min-height: 0;
+    background: rgba(245, 237, 228, 0.82);
+    border-right: 1px solid rgba(35,26,17,0.1);
+    display: flex;
+    flex-direction: column;
+    overflow-y: auto;
+    padding: 16px 0 12px;
+    backdrop-filter: blur(16px);
   }
-  .sidebar-tabs { display: flex; gap: 2px; margin-bottom: 10px; background: rgba(35,26,17,0.04); border-radius: 10px; padding: 3px; }
-  .sidebar-tab {
-    flex: 1; padding: 6px 0; border-radius: 8px; font-size: 0.8rem; font-weight: 600;
-    color: #7d6f61; background: none; border: none; font-family: var(--font); transition: all 160ms;
+  .sidebar-header { display: flex; align-items: center; gap: 8px; padding: 0 18px 12px; }
+  .sidebar-header svg { color: #7f5f3d; }
+  .sidebar-title { font-size: 1rem; font-weight: 700; color: #1f1811; letter-spacing: -0.03em; }
+
+  .sidebar-nav { display: flex; flex-direction: column; gap: 4px; padding: 0 12px; }
+  .nav-item {
+    display: flex; align-items: center; gap: 8px;
+    padding: 10px 12px; border-radius: 14px; background: none; border: none;
+    font-size: 0.85rem; color: #65584c; cursor: pointer;
+    transition: all 160ms; text-align: left; width: 100%; font-family: var(--font);
   }
-  .sidebar-tab.active { background: rgba(255,255,255,0.9); color: #1e1812; box-shadow: 0 1px 3px rgba(35,26,17,0.06); }
+  .nav-item:hover { background: rgba(255,248,241,0.72); color: #1f1811; }
+  .nav-item.active { background: rgba(255,248,241,0.92); color: #1f1811; font-weight: 600; box-shadow: inset 0 0 0 1px rgba(35,26,17,0.08); }
+  .nav-label { flex: 1; }
+  .nav-count { font-size: 0.72rem; color: #8a7a68; font-family: var(--mono); }
 
-  .sidebar-item {
-    display: flex; align-items: center; gap: 8px; width: 100%; padding: 8px 10px;
-    border-radius: 10px; border: none; background: none; font-family: var(--font);
-    font-size: 0.85rem; color: #3d342c; text-align: left; transition: all 160ms;
+  .sidebar-separator { height: 1px; background: rgba(35,26,17,0.08); margin: 12px 18px; }
+  .sidebar-section-label { font-size: 0.68rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.14em; color: #8c7b69; padding: 0 18px 6px; }
+
+  .brain-content {
+    flex: 1;
+    min-width: 0;
+    padding: 0 24px;
+    overflow-y: auto;
   }
-  .sidebar-item:hover { background: rgba(255,255,255,0.6); }
-  .sidebar-item.active { background: linear-gradient(135deg, rgba(255,248,242,0.94), rgba(246,237,227,0.72)); color: #1e1812; font-weight: 600; }
-  .sidebar-item-name { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
-  .sidebar-item-count { flex-shrink: 0; font-size: 0.72rem; font-family: var(--mono); color: #8c7b69; background: rgba(35,26,17,0.04); padding: 1px 6px; border-radius: 6px; }
-  .sidebar-item-delete { flex-shrink: 0; width: 20px; height: 20px; border-radius: 6px; border: none; background: none; color: #8c7b69; display: flex; align-items: center; justify-content: center; }
-  .sidebar-item-delete:hover { background: rgba(220,38,38,0.1); color: #DC2626; }
-
-  .sidebar-actions { margin-top: 10px; padding-top: 10px; border-top: 1px solid rgba(35,26,17,0.06); display: flex; flex-direction: column; gap: 6px; }
-  .sidebar-add { display: flex; gap: 4px; }
-  .sidebar-add-input { flex: 1; padding: 6px 10px; border-radius: 8px; border: 1px solid rgba(35,26,17,0.1); background: rgba(255,255,255,0.7); font-size: 0.8rem; font-family: var(--font); color: #1e1812; outline: none; }
-  .sidebar-add-input:focus { border-color: rgba(179,92,50,0.4); }
-  .sidebar-add-input::placeholder { color: #8c7b69; }
-  .sidebar-add-btn { padding: 6px 10px; border-radius: 8px; border: none; background: #1e1812; color: white; font-size: 0.78rem; font-weight: 600; font-family: var(--font); }
-  .sidebar-manage-toggle { padding: 6px 0; border: none; background: none; font-size: 0.78rem; color: #8c7b69; font-family: var(--font); text-align: center; }
-  .sidebar-manage-toggle:hover { color: #1e1812; }
-
-  .brain-main { min-width: 0; }
 
   /* ═══ Active filter ═══ */
   .active-filter {
@@ -1170,13 +1216,12 @@
   /* ═══ Mobile ═══ */
   @media (max-width: 1100px) {
     .masonry { columns: 2; }
-    .brain-layout { grid-template-columns: 200px 1fr; }
   }
   @media (max-width: 768px) {
     .brain-command { display: grid; gap: 14px; }
     .command-actions { justify-items: start; }
-    .brain-layout { grid-template-columns: 1fr; }
-    .brain-sidebar { position: static; max-height: none; }
+    .brain-sidebar { display: none; }
+    .brain-layout { margin: 0; }
     .masonry { columns: 1; }
     .detail-sheet { width: 100%; padding: 20px; }
     .viewer-overlay { padding: 12px; }