Shows a way to inherit styles and add to it in WPF

Cascading Styles WPF

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
   <Grid>
      <Grid.Resources>
         <Style BasedOn="{StaticResource {x:Type Button}}" TargetType="{x:Type Button}">
            <Setter Property="Background" Value="Blue"/>
         </Style>
      </Grid.Resources>
      <Border
         HorizontalAlignment="Center"
         VerticalAlignment="Center"
         BorderBrush="Gray"
         BorderThickness="2"
         CornerRadius="2">
         <Border.Resources>
            <Style BasedOn="{StaticResource {x:Type Button}}" TargetType="{x:Type Button}">
               <Setter Property="Foreground" Value="White"/>
            </Style>
         </Border.Resources>
         <StackPanel>
            <StackPanel.Resources>
              <Style BasedOn="{StaticResource {x:Type Button}}" TargetType="{x:Type Button}">
               <Setter Property="FontStyle" Value="Italic"/>
            </Style>
            </StackPanel.Resources>
            <Button Content="Click the Waterfall"/>
            
         </StackPanel>
      </Border>
   </Grid>
</Page>