diff --git a/demo/Semi.Avalonia.Demo/Pages/HeaderedContentControlDemo.axaml b/demo/Semi.Avalonia.Demo/Pages/HeaderedContentControlDemo.axaml
index b778b13..59baf5e 100644
--- a/demo/Semi.Avalonia.Demo/Pages/HeaderedContentControlDemo.axaml
+++ b/demo/Semi.Avalonia.Demo/Pages/HeaderedContentControlDemo.axaml
@@ -36,10 +36,20 @@
-
-
-
+
+ Real GroupBox
+
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/src/Semi.Avalonia/Controls/GroupBox.axaml b/src/Semi.Avalonia/Controls/GroupBox.axaml
new file mode 100644
index 0000000..97cb4d2
--- /dev/null
+++ b/src/Semi.Avalonia/Controls/GroupBox.axaml
@@ -0,0 +1,6 @@
+
+
+
\ No newline at end of file
diff --git a/src/Semi.Avalonia/Controls/HeaderedContentControl.axaml b/src/Semi.Avalonia/Controls/HeaderedContentControl.axaml
index 66b2bfd..1a28f09 100644
--- a/src/Semi.Avalonia/Controls/HeaderedContentControl.axaml
+++ b/src/Semi.Avalonia/Controls/HeaderedContentControl.axaml
@@ -1,7 +1,8 @@
+ xmlns:iri="https://irihi.tech/shared"
+ x:CompileBindings="True">
-
@@ -97,7 +97,7 @@
Name="SeparatorBorder"
Grid.Row="1"
BorderBrush="{TemplateBinding BorderBrush}"
- BorderThickness="{TemplateBinding BorderThickness, Converter={StaticResource SeparatorBorderMultiplier}}">
+ BorderThickness="{TemplateBinding BorderThickness, Converter={iri:ThicknessMixerConverter Top}}">
diff --git a/src/Semi.Avalonia/Controls/_index.axaml b/src/Semi.Avalonia/Controls/_index.axaml
index 084607d..66ee144 100644
--- a/src/Semi.Avalonia/Controls/_index.axaml
+++ b/src/Semi.Avalonia/Controls/_index.axaml
@@ -22,6 +22,7 @@
+