Correção do Botão de esconderbarra lateral principal

app/views/layouts/_navbar.html.erb

@@ -71,6 +71,15 @@
   </div>
 </aside>
 
+<%# Botão flutuante (desktop) — esconde/mostra a sidebar do site inteiro %>
+<button id="sidebar-toggle-btn" type="button" onclick="toggleSidebarCollapse()"
+        class="hidden md:flex fixed top-1/2 -translate-y-1/2 z-40 items-center justify-center
+               w-7 h-16 bg-[#1a1a1a] border border-[#2a2a2a] hover:border-orange-500
+               text-orange-500 rounded-r-lg shadow-lg"
+        title="Esconder/mostrar menu" aria-label="Esconder ou mostrar o menu">
+  <span id="sidebar-toggle-icon" class="text-lg leading-none">◀</span>
+</button>
+
 <%# Topbar mobile %>
 <header class="md:hidden fixed top-0 left-0 right-0 z-30 bg-[#111111] border-b border-[#2a2a2a] px-4 py-3 flex items-center justify-between">
   <button onclick="toggleSidebar()"
@@ -86,10 +95,24 @@
 <div class="h-14 md:hidden"></div>
 
 <script>
+  // Mobile: abre/fecha a sidebar por cima do conteúdo (hamburguer).
   function toggleSidebar() {
     const s = document.getElementById('sidebar');
     const o = document.getElementById('sidebar-overlay');
     s.classList.toggle('-translate-x-full');
     o.classList.toggle('hidden');
   }
+
+  // Desktop: recolhe/expande a sidebar (estado salvo p/ o site inteiro).
+  function toggleSidebarCollapse() {
+    const collapsed = document.documentElement.classList.toggle('sidebar-collapsed');
+    try { localStorage.setItem('sidebarCollapsed', collapsed ? '1' : '0'); } catch (e) {}
+    syncSidebarToggleIcon();
+  }
+  function syncSidebarToggleIcon() {
+    const icon = document.getElementById('sidebar-toggle-icon');
+    if (icon) icon.textContent =
+      document.documentElement.classList.contains('sidebar-collapsed') ? '▶' : '◀';
+  }
+  syncSidebarToggleIcon();
 </script>