diff --git a/src/request_tab_widget.py b/src/request_tab_widget.py
index fc9ca8d..ee8eb60 100644
--- a/src/request_tab_widget.py
+++ b/src/request_tab_widget.py
@@ -429,6 +429,14 @@ class RequestTabWidget(Gtk.Box):
 
             self.narrow_stack.add_named(self.request_panel, "request")
             self.narrow_stack.add_named(self.response_panel, "response")
+
+            # Sync stack visible child to match current button state
+            # (button state persists across wide↔narrow transitions)
+            if self.narrow_response_btn.get_active():
+                self.narrow_stack.set_visible_child_name("response")
+            else:
+                self.narrow_stack.set_visible_child_name("request")
+
             self.append(self.narrow_box)
         else:
             self.narrow_stack.remove(self.request_panel)