Add border to trim.
MODIFY
WalletWasabi.Fluent/Views/MainView.axaml
WalletWasabi.Fluent/Views/MainView.axaml
<navbar:NavBar Grid.Row="1" Grid.Column="0" DataContext="{Binding NavBar}" />
- <Border Grid.Row="1" Grid.Column="1" Grid.ColumnSpan="2" CornerRadius="10 0 0 0" ClipToBounds="True">
+ <Border Grid.Row="1" Grid.Column="1" BorderBrush="{DynamicResource TileBorderColor}" BorderThickness="1 1 0 0" Grid.ColumnSpan="2" CornerRadius="10 0 0 0" ClipToBounds="True">
<Panel>
<Border CornerRadius="10 0 0 0" Background="{DynamicResource RegionColor}" ClipToBounds="True" IsHitTestVisible="False" />
<Panel VerticalAlignment="Bottom"

Add border to trim.