diff --git a/MainWindow.xaml b/MainWindow.xaml
index 9b807d0..1f22628 100644
--- a/MainWindow.xaml
+++ b/MainWindow.xaml
@@ -155,9 +155,9 @@
 
         <Grid Grid.Row="2" Margin="8">
             <Grid.ColumnDefinitions>
-                <ColumnDefinition Width="220"/>
-                <ColumnDefinition Width="*"/>
-                <ColumnDefinition Width="300"/>
+                <ColumnDefinition Width="1*" MinWidth="220"/>
+                <ColumnDefinition Width="2*"/>
+                <ColumnDefinition Width="1*" MinWidth="300"/>
             </Grid.ColumnDefinitions>
 
             <!-- LEFT PANEL: Scenes & Sources -->