Avalonia/samples/ControlCatalog/NavHeaderItem.xaml

<ResourceDictionary xmlns="https://github.com/avaloniaui"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:controls="using:ControlCatalog">
  

  <ResourceDictionary.ThemeDictionaries>
    <ResourceDictionary x:Key="Dark">
      <Color x:Key="HamburgerBaseHighColor">#99FFFFFF</Color>
      <Color x:Key="HamburgerChromeMediumColor">#FF1F1F1F</Color>
      <Color x:Key="HamburgerAltHighColor">#FF000000</Color>
      <Color x:Key="HamburgerChromeLowColor">#FF171717</Color>
    </ResourceDictionary>
    <ResourceDictionary x:Key="Default">
      <Color x:Key="HamburgerBaseHighColor">#99000000</Color>
      <Color x:Key="HamburgerChromeMediumColor">#FFE6E6E6</Color>
      <Color x:Key="HamburgerAltHighColor">#FFFFFFFF</Color>
      <Color x:Key="HamburgerChromeLowColor">#FFF2F2F2</Color>
    </ResourceDictionary>
  </ResourceDictionary.ThemeDictionaries> 
  <x:Double x:Key="NavigationItemHeight">36</x:Double>
  <BoxShadows x:Key="NavigationItemShadow">1 1 1 1 #2000, 0 0 1 1 #2fff</BoxShadows>
  <Design.PreviewWith>
    <Border Padding="0">
      <ListBox ItemContainerTheme="{StaticResource NavHeaderItem}">
        <ListBoxItem IsEnabled="False">Disabled</ListBoxItem>
        <ListBoxItem>
          Test
        </ListBoxItem>
        <ListBoxItem>Test</ListBoxItem>
      </ListBox>
    </Border>
  </Design.PreviewWith>
  <ControlTheme x:Key="NavHeaderItem" TargetType="ListBoxItem">
    <Setter Property="HorizontalContentAlignment" Value="Stretch" />
    <Setter Property="VerticalContentAlignment" Value="Center" />
    <Setter Property="HorizontalAlignment" Value="Stretch" />
    <Setter Property="VerticalAlignment" Value="Stretch" />
    <Setter Property="Background" Value="Transparent" />
    <Setter Property="Height" Value="{StaticResource NavigationItemHeight}" />
    <Setter Property="Padding" Value="14,0,4,0" />
    <Setter Property="Margin" Value="4,2,8,0" />
    <Setter Property="CornerRadius" Value="8" />
    <Setter Property="ClipToBounds" Value="False" />
    <Setter Property="Template">
      <ControlTemplate>
        <Border Name="PART_LayoutRoot"
                HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
                Background="{TemplateBinding Background}"
                BorderBrush="{TemplateBinding BorderBrush}"
                BorderThickness="{TemplateBinding BorderThickness}"
                CornerRadius="{TemplateBinding CornerRadius}">
          <Panel>
            <Border Name="PART_SelectedPipe"
                    Width="{DynamicResource TabItemPipeThickness}"
                    Height="{DynamicResource TabItemVerticalPipeHeight}"
                    Margin="6,0,0,0"
                    HorizontalAlignment="Left"
                    VerticalAlignment="Center"
                    Background="{DynamicResource TabItemHeaderSelectedPipeFill}"
                    IsVisible="False"
                    CornerRadius="4"/>
            <ContentPresenter Name="PART_ContentPresenter"
                              Padding="{TemplateBinding Padding}"
                              Margin="0"
                              HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                              VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                              Content="{TemplateBinding Content}"
                          ContentTemplate="{TemplateBinding ContentTemplate}"
                              TextElement.FontFamily="{TemplateBinding FontFamily}"
                              TextElement.FontSize="{TemplateBinding FontSize}"
                              TextElement.FontWeight="{TemplateBinding FontWeight}" />
          </Panel>
        </Border>
      </ControlTemplate>
    </Setter>    

    <Style Selector="^:pointerover">
      <Setter Property="Background" Value="{DynamicResource ThemeControlHighlightMidBrush}"/>

      <Style Selector="^ /template/ Border#PART_LayoutRoot">
        <Setter Property="Background" Value="{DynamicResource HamburgerChromeLowColor}" />
        <Setter Property="BoxShadow" Value="{StaticResource NavigationItemShadow}" />
        <Setter Property="TextElement.Foreground" Value="{DynamicResource HamburgerBaseHighColor}" />
      </Style>
    </Style>

    <Style Selector="^:selected">
      <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush4}"/>

      <Style Selector="^ /template/ Border#PART_SelectedPipe">
        <Setter Property="IsVisible" Value="True" />
      </Style>
    </Style>

    <Style Selector="^:pressed /template/ Border#PART_LayoutRoot">
      <Setter Property="Border.Background" Value="{DynamicResource HamburgerChromeLowColor}" />
      <Setter Property="Border.BoxShadow" Value="{StaticResource NavigationItemShadow}" />
      <Setter Property="TextElement.Foreground" Value="{DynamicResource HamburgerBaseHighColor}" />
    </Style>
  </ControlTheme>
</ResourceDictionary>