[gtk/wip/exalm/separator: 1/2] demo: Use .sidebar style class on the separator

[Alexander Mikhaylenko <alexm src gnome org>]

commit f3add9f8bfd4a87171e2f3a3abeb0513271cd157
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Sun Nov 22 15:27:18 2020 +0500

    demo: Use .sidebar style class on the separator

 demos/gtk-demo/main.ui | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/demos/gtk-demo/main.ui b/demos/gtk-demo/main.ui
index 58f8d823d7..b40075a764 100644
--- a/demos/gtk-demo/main.ui
+++ b/demos/gtk-demo/main.ui
@@ -90,7 +90,11 @@
           </object>
         </child>
         <child>
-          <object class="GtkSeparator"/>
+          <object class="GtkSeparator">
+            <style>
+              <class name="sidebar"/>
+            </style>
+          </object>
         </child>
         <child>
           <object class="GtkNotebook" id="notebook">