diff --git a/demo/Semi.Avalonia.Demo/Views/MainView.axaml b/demo/Semi.Avalonia.Demo/Views/MainView.axaml
index f26e226..3eb3ccd 100644
--- a/demo/Semi.Avalonia.Demo/Views/MainView.axaml
+++ b/demo/Semi.Avalonia.Demo/Views/MainView.axaml
@@ -19,6 +19,7 @@
                     <TextBlock
                         FontWeight="Bold"
                         FontSize="12"
+                        Margin="4"
                         Text="{TemplateBinding Header}" />
                 </ControlTemplate>
             </Setter>