diff --git a/web/src/__tests__/desktop-shell-context.test.tsx b/web/src/__tests__/desktop-shell-context.test.tsx
index a28a38b8..9cce2b67 100644
--- a/web/src/__tests__/desktop-shell-context.test.tsx
+++ b/web/src/__tests__/desktop-shell-context.test.tsx
@@ -153,6 +153,33 @@ describe('desktop shell recovery', () => {
     expect(window.localStorage.getItem('veritas.desktop.rightRailOpen')).toBe('false');
   });
 
+  it('keeps the task history and focus when resize collapses the chat behind it', async () => {
+    const user = userEvent.setup();
+    render(
+      <DesktopShellProvider>
+        <ShellProbe />
+      </DesktopShellProvider>
+    );
+    await user.click(screen.getByRole('button', { name: 'Open board chat' }));
+    const taskState = { ...window.history.state, veritasTaskDetail: 'task-open-above-chat' };
+    window.history.pushState(taskState, '', '/');
+    const taskControl = screen.getByRole('button', { name: 'Reset layout' });
+    taskControl.focus();
+    const back = vi.spyOn(window.history, 'back').mockImplementation(() => {});
+    try {
+      Object.defineProperty(window, 'innerWidth', { configurable: true, value: 1180 });
+      act(() => window.dispatchEvent(new Event('resize')));
+      expect(screen.getByLabelText('bottom panel').textContent).toBe('closed');
+      expect(window.history.state.veritasTaskDetail).toBe('task-open-above-chat');
+      expect(window.history.state.veritasBottomPanel).toBeUndefined();
+      expect(back).not.toHaveBeenCalled();
+      await new Promise<void>((resolve) => requestAnimationFrame(() => resolve()));
+      expect(document.activeElement).toBe(taskControl);
+    } finally {
+      back.mockRestore();
+    }
+  });
+
   it('minimizes both sidebars before opening Workbench at compact width', async () => {
     const user = userEvent.setup();
     Object.defineProperty(window, 'innerWidth', { configurable: true, value: 1180 });
diff --git a/web/src/components/layout/DesktopShellContext.tsx b/web/src/components/layout/DesktopShellContext.tsx
index 44d23c1c..f0eed9d8 100644
--- a/web/src/components/layout/DesktopShellContext.tsx
+++ b/web/src/components/layout/DesktopShellContext.tsx
@@ -314,7 +314,15 @@ export function DesktopShellProvider({ children }: { children: ReactNode }) {
       setRightRailOpenState(false);
       writeStoredValue(LEFT_RAIL_STORAGE_KEY, 'false');
       writeStoredValue(RIGHT_RAIL_STORAGE_KEY, 'false');
-      if (bottomPanel) closeBottomPanel();
+      if (bottomPanel) {
+        // A layout collapse is not navigation: a task opened above the dock
+        // inherits its history marker. Going Back would dismiss that task.
+        setBottomPanel(null);
+        removeStoredValue(BOTTOM_PANEL_STORAGE_KEY);
+        panelTriggerRef.current = null;
+        const { [BOTTOM_PANEL_HISTORY_STATE_KEY]: _panel, ...rest } = window.history.state ?? {};
+        window.history.replaceState(rest, '', window.location.href);
+      }
     };
 
     window.addEventListener('keydown', handleKeyDown, true);