Set correct margin
MODIFY
WalletWasabi.Fluent/Views/ResponsivePanelDemo/ResponsivePanelDemoView.axaml
WalletWasabi.Fluent/Views/ResponsivePanelDemo/ResponsivePanelDemoView.axaml
<!-- For fixed height set RowDefinitions="350,*" and AspectRatio="NaN" -->
<!-- When ItemWidth and ItemHeight are NaN AspectRatio and ColumnHints is using for sizing items -->
- <StackPanel DockPanel.Dock="Left" Width="200" Margin="0,12,0,0">
+ <StackPanel DockPanel.Dock="Left" Width="200" Margin="0,0,20,0">
<Label Content="ItemWidth"/>
<TextBox Text="{Binding ItemWidth}"/>
<Label Content="ItemHeight"/>

Set correct margin