In XAML TabControl, how to set the style of the focused tab header?

I can set the background of each TabItem with TabItem.Background, but when that tab is selected it is plain vanilla white.

How do I set the style of the tab header that is focused?

<TabControl DockPanel.Dock="Top">
    <TabControl.Background>
        <LinearGradientBrush EndPoint="1.115,1.13" StartPoint="0,-0.02">
            <GradientStop Color="#FFFFFFFF" Offset="1"/>
            <GradientStop Color="#FFE0E376" Offset="0"/>
        </LinearGradientBrush>
    </TabControl.Background>

    <TabItem Header="Allgem." Cursor="Hand">
        <TabItem.Background>
            <LinearGradientBrush EndPoint="0,1" StartPoint="0,0">
                <GradientStop Color="#FFF3F3F3" Offset="0"/>
                <GradientStop Color="#FFF11818" Offset="1"/>
            </LinearGradientBrush>
        </TabItem.Background>
        <StackPanel DockPanel.Dock="Bottom" Width="400" HorizontalAlignment="Left" Margin="10">
            ...

From stackoverflow

• You can use a trigger to change the style only for the selected tab:

  <TabControl DockPanel.Dock="Top">
      <TabControl.Resources>
          <Style TargetType="{x:Type TabItem}">
              <Style.Triggers>
                  <Trigger Property="IsSelected" Value="True">
                      <Setter Property="Background">
                          <Setter.Value>
                              <LinearGradientBrush EndPoint="0,1" StartPoint="0,0">
                                  <GradientStop Color="#FFF3F3F3" Offset="0"/>
                                  <GradientStop Color="#FFF11818" Offset="1"/>
                              </LinearGradientBrush>
                          </Setter.Value>
                      </Setter>
                  </Trigger>
              </Style.Triggers>
          </Style>
      </TabControl.Resources>
      <TabControl.Background>
          <LinearGradientBrush EndPoint="1.115,1.13" StartPoint="0,-0.02">
              <GradientStop Color="#FFFFFFFF" Offset="1"/>
              <GradientStop Color="#FFE0E376" Offset="0"/>
          </LinearGradientBrush>
      </TabControl.Background>
      <TabItem Header="Allgem." Cursor="Hand">
          <StackPanel DockPanel.Dock="Bottom" Width="400"
              HorizontalAlignment="Left" Margin="10">
          ...
          </StackPanel>
      </TabItem>
  </TabControl>
  

  This will set the background of the selected tab to the red gradient used in your sample code.