diff --git a/MainWindow.xaml b/MainWindow.xaml
index 1f22628..18ebf5f 100644
--- a/MainWindow.xaml
+++ b/MainWindow.xaml
@@ -155,9 +155,9 @@
 
         <Grid Grid.Row="2" Margin="8">
             <Grid.ColumnDefinitions>
-                <ColumnDefinition Width="1*" MinWidth="220"/>
+                <ColumnDefinition Width="1*" MinWidth="220" MaxWidth="360"/>
                 <ColumnDefinition Width="2*"/>
-                <ColumnDefinition Width="1*" MinWidth="300"/>
+                <ColumnDefinition Width="1*" MinWidth="300" MaxWidth="400"/>
             </Grid.ColumnDefinitions>
 
             <!-- LEFT PANEL: Scenes & Sources -->