diff --git a/app/styles.css b/app/styles.css
index 2e5f642..6aee23a 100644
--- a/app/styles.css
+++ b/app/styles.css
@@ -58,6 +58,34 @@
       line-height: 1;
       flex: 0 0 auto;
     }
+    .topbar-panel-toggle {
+      display: inline-flex;
+      align-items: center;
+      justify-content: center;
+      padding: 7px 12px;
+      border-radius: 999px;
+      border: 1px solid #3f3f46;
+      background: #27272a;
+      color: #f4f4f5;
+      cursor: pointer;
+      font-size: 13px;
+      font-weight: 600;
+      line-height: 1;
+      flex: 0 0 auto;
+      margin-left: auto;
+    }
+    .topbar-panel-toggle:hover {
+      background: #3f3f46;
+    }
+    .topbar-panel-toggle[hidden] {
+      display: none;
+    }
+    .topbar-panel-toggle[hidden] + .topbar-menu-toggle {
+      margin-left: auto;
+    }
+    .topbar-panel-toggle:not([hidden]) + .topbar-menu-toggle {
+      margin-left: 0;
+    }
     .topbar-menu-toggle:hover {
       background: #3f3f46;
     }
@@ -158,7 +186,9 @@
       }
       .topbar-menu-toggle {
         min-height: 38px;
-        margin-left: auto;
+      }
+      .topbar-panel-toggle {
+        min-height: 38px;
       }
       .topbar.is-menu-open {
         flex-wrap: nowrap;
@@ -2123,13 +2153,6 @@
       pointer-events: auto;
     }
 
-    .sidebar-popout-open {
-      position: absolute;
-      top: 10px;
-      right: 10px;
-      z-index: 5;
-    }
-
     .detail-popout-open {
       position: absolute;
       top: 10px;
@@ -5960,7 +5983,6 @@
         min-height: 38px;
         padding: 8px 10px;
       }
-      .sidebar-popout-open,
       .detail-popout-open {
         position: fixed;
         top: auto;
@@ -5976,9 +5998,6 @@
         -webkit-backdrop-filter: blur(10px);
         backdrop-filter: blur(10px);
       }
-      .sidebar-popout-open {
-        right: 14px;
-      }
       .detail-popout-open {
         left: 14px;
       }
diff --git a/app/ui-chrome.js b/app/ui-chrome.js
index bab8f6f..d063044 100644
--- a/app/ui-chrome.js
+++ b/app/ui-chrome.js
@@ -6,6 +6,7 @@
   const DEFAULT_DATASET_ENTRY_COLLAPSED = false;
   const DEFAULT_DATASET_DETAIL_COLLAPSED = true;
   const sidebarControllers = new WeakMap();
+  const sidebarControllerRegistry = new Map();
   const detailControllers = new WeakMap();
   const AUTO_COLLAPSE_ENTRY_SELECTOR = [
     ".planet-list-item",
@@ -162,6 +163,131 @@
     return resolveLayoutTarget(panel);
   }
 
+  function isLayoutVisible(layout) {
+    if (!(layout instanceof HTMLElement)) {
+      return false;
+    }
+
+    if (layout.hidden || layout.closest("[hidden]")) {
+      return false;
+    }
+
+    const section = layout.closest("section");
+    if (section instanceof HTMLElement && section.hidden) {
+      return false;
+    }
+
+    return true;
+  }
+
+  function getActiveVisibleSidebarController() {
+    for (const controller of sidebarControllerRegistry.values()) {
+      if (!isLayoutVisible(controller.layout)) {
+        continue;
+      }
+
+      return controller;
+    }
+
+    return null;
+  }
+
+  function getTopbarPanelToggleButton() {
+    const { topbarEl, menuToggleEl } = getTopbarElements();
+    if (!(topbarEl instanceof HTMLElement) || !(menuToggleEl instanceof HTMLButtonElement)) {
+      return null;
+    }
+
+    const existingButton = topbarEl.querySelector("#topbar-panel-toggle");
+    if (existingButton instanceof HTMLButtonElement) {
+      return existingButton;
+    }
+
+    const panelToggleEl = document.createElement("button");
+    panelToggleEl.id = "topbar-panel-toggle";
+    panelToggleEl.type = "button";
+    panelToggleEl.className = "topbar-panel-toggle sidebar-popout-open";
+    panelToggleEl.textContent = "Show Detail";
+    panelToggleEl.setAttribute("aria-label", "Show detail view");
+    panelToggleEl.hidden = true;
+    panelToggleEl.addEventListener("click", () => {
+      const controller = getActiveVisibleSidebarController();
+      if (!controller) {
+        return;
+      }
+
+      if (controller.layout.classList.contains("layout-sidebar-collapsed")) {
+        showSidebarOnly(controller.layout);
+        return;
+      }
+
+      if (detailControllers.has(controller.layout)) {
+        showDetailOnly(controller.layout);
+      }
+    });
+
+    topbarEl.insertBefore(panelToggleEl, menuToggleEl);
+    return panelToggleEl;
+  }
+
+  function syncTopbarPanelToggleButton() {
+    const panelToggleEl = getTopbarPanelToggleButton();
+    if (!(panelToggleEl instanceof HTMLButtonElement)) {
+      return;
+    }
+
+    const controller = getActiveVisibleSidebarController();
+    if (!controller) {
+      panelToggleEl.hidden = true;
+      panelToggleEl.removeAttribute("aria-controls");
+      panelToggleEl.setAttribute("aria-expanded", "false");
+      return;
+    }
+
+    const sidebarCollapsed = controller.layout.classList.contains("layout-sidebar-collapsed");
+    const hasDetailController = detailControllers.has(controller.layout);
+    if (!sidebarCollapsed && !hasDetailController) {
+      panelToggleEl.hidden = true;
+      panelToggleEl.removeAttribute("aria-controls");
+      panelToggleEl.setAttribute("aria-expanded", "false");
+      return;
+    }
+
+    panelToggleEl.hidden = false;
+    panelToggleEl.setAttribute("aria-controls", controller.panel.id);
+    panelToggleEl.setAttribute("aria-expanded", sidebarCollapsed ? "false" : "true");
+    panelToggleEl.textContent = sidebarCollapsed ? "Show Panel" : "Show Detail";
+    panelToggleEl.setAttribute("aria-label", sidebarCollapsed ? "Show entry panel" : "Show detail view");
+  }
+
+  function initializeTopbarPanelToggle() {
+    if (!document.body || document.body.dataset.topbarPanelToggleReady === "1") {
+      syncTopbarPanelToggleButton();
+      return;
+    }
+
+    document.body.dataset.topbarPanelToggleReady = "1";
+    getTopbarPanelToggleButton();
+
+    const observer = new MutationObserver(() => {
+      window.requestAnimationFrame(() => {
+        syncTopbarPanelToggleButton();
+      });
+    });
+
+    observer.observe(document.body, {
+      subtree: true,
+      attributes: true,
+      attributeFilter: ["hidden", "class"]
+    });
+
+    window.addEventListener("resize", () => {
+      syncTopbarPanelToggleButton();
+    });
+
+    syncTopbarPanelToggleButton();
+  }
+
   function scheduleAutoCollapse(layout) {
     if (!(layout instanceof HTMLElement)) {
       return;
@@ -221,11 +347,6 @@
         return;
       }
 
-      const header = panel.querySelector(".planet-list-header, .tarot-list-header");
-      if (!(header instanceof HTMLElement)) {
-        return;
-      }
-
       panel.dataset.sidebarPopoutReady = "1";
 
       const sectionId = layout.closest("section")?.id || `layout-${index + 1}`;
@@ -234,53 +355,30 @@
 
       const storageKey = `${SIDEBAR_COLLAPSE_STORAGE_PREFIX}${sectionId}`;
 
-      const collapseBtn = document.createElement("button");
-      collapseBtn.type = "button";
-      collapseBtn.className = "sidebar-toggle-inline";
-      collapseBtn.textContent = "Hide Panel";
-      collapseBtn.setAttribute("aria-label", "Hide entry panel");
-      collapseBtn.setAttribute("aria-controls", panelId);
-      header.appendChild(collapseBtn);
-
-      const openBtn = document.createElement("button");
-      openBtn.type = "button";
-      openBtn.className = "sidebar-popout-open";
-      openBtn.textContent = "Show Panel";
-      openBtn.setAttribute("aria-label", "Show entry panel");
-      openBtn.setAttribute("aria-controls", panelId);
-      openBtn.hidden = true;
-      layout.appendChild(openBtn);
-
       const applyCollapsedState = (collapsed, persist = true) => {
         layout.classList.toggle("layout-sidebar-collapsed", collapsed);
-        collapseBtn.setAttribute("aria-expanded", collapsed ? "false" : "true");
-        openBtn.setAttribute("aria-expanded", collapsed ? "false" : "true");
-        openBtn.hidden = !collapsed;
+        syncTopbarPanelToggleButton();
 
         if (persist) {
           saveSidebarCollapsedState(storageKey, collapsed);
         }
       };
 
-      sidebarControllers.set(layout, {
+      const controller = {
+        layout,
         applyCollapsedState,
         panel,
-        collapseBtn,
-        openBtn,
         storageKey
-      });
+      };
 
-      collapseBtn.addEventListener("click", () => {
-        showDetailOnly(layout);
-      });
-
-      openBtn.addEventListener("click", () => {
-        showSidebarOnly(layout);
-      });
+      sidebarControllers.set(layout, controller);
+      sidebarControllerRegistry.set(layout, controller);
 
       const storedCollapsed = loadSidebarCollapsedState(storageKey);
       applyCollapsedState(storedCollapsed == null ? DEFAULT_DATASET_ENTRY_COLLAPSED : storedCollapsed, false);
     });
+
+    syncTopbarPanelToggleButton();
   }
 
   function initializeDetailPopouts() {
@@ -322,6 +420,7 @@
 
         layout.classList.toggle("layout-detail-collapsed", collapsed);
         detailPanel.setAttribute("aria-hidden", collapsed ? "true" : "false");
+        syncTopbarPanelToggleButton();
 
         if (persist) {
           saveSidebarCollapsedState(detailStorageKey, collapsed);
@@ -503,6 +602,7 @@
     initializeSidebarAutoCollapse();
     bindTopbarMobileMenu();
     bindTopbarDropdownInteractions();
+    initializeTopbarPanelToggle();
   }
 
   window.TarotChromeUi = {
@@ -512,6 +612,7 @@
     initializeDetailPopouts,
     initializeSidebarAutoCollapse,
     bindTopbarMobileMenu,
+    initializeTopbarPanelToggle,
     setSidebarCollapsed,
     setDetailCollapsed,
     showDetailOnly,
diff --git a/index.html b/index.html
index 72284db..51fd6a3 100644
--- a/index.html
+++ b/index.html
@@ -16,7 +16,7 @@
   <link rel="stylesheet" href="node_modules/@fontsource/amiri/arabic-400.css">
   <link rel="stylesheet" href="node_modules/@fontsource/amiri/arabic-700.css">
   <link rel="stylesheet" href="node_modules/@fontsource/noto-naskh-arabic/arabic-400.css">
-  <link rel="stylesheet" href="app/styles.css?v=20260314-audio-circle-01">
+  <link rel="stylesheet" href="app/styles.css?v=20260314-topbar-panel-toggle-01">
 </head>
 <body>
   <div class="topbar">
@@ -1086,7 +1086,7 @@
   <script src="app/ui-numbers.js"></script>
   <script src="app/ui-tarot-spread.js"></script>
   <script src="app/ui-settings.js?v=20260309-gate"></script>
-  <script src="app/ui-chrome.js?v=20260314-mobile-menu-overlay-01"></script>
+  <script src="app/ui-chrome.js?v=20260314-topbar-panel-toggle-02"></script>
   <script src="app/ui-navigation.js?v=20260314-audio-circle-01"></script>
   <script src="app/ui-calendar-formatting.js?v=20260307b"></script>
   <script src="app/ui-calendar-visuals.js?v=20260307b"></script>