sourcegit/SourceGit/Resources/Styles/TabControl.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Style TargetType="{x:Type TabControl}">
        <Setter Property="OverridesDefaultStyle" Value="True" />
        <Setter Property="SnapsToDevicePixels" Value="True" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type TabControl}">
                    <Grid KeyboardNavigation.TabNavigation="Local">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="Auto" />
                            <RowDefinition Height="*" />
                        </Grid.RowDefinitions>
                        <TabPanel x:Name="HeaderPanel" Grid.Row="0" IsItemsHost="True" KeyboardNavigation.TabIndex="1" Background="Transparent" />
                        <Border 
                            x:Name="Border" 
                            Grid.Row="1" 
                            Background="Transparent"    
                            KeyboardNavigation.TabNavigation="Local"
                            KeyboardNavigation.DirectionalNavigation="Contained"
                            KeyboardNavigation.TabIndex="2">
                            <ContentPresenter x:Name="PART_SelectedContentHost" Margin="4" ContentSource="SelectedContent" />
                        </Border>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <Style TargetType="{x:Type TabItem}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type TabItem}">
                    <Border x:Name="Border" Margin="0" BorderThickness="0,0,0,1.1" BorderBrush="Transparent" Opacity=".7">
                        <ContentPresenter 
                            x:Name="ContentSite" 
                            VerticalAlignment="Center" HorizontalAlignment="Center" 
                            TextElement.Foreground="{DynamicResource Brush.FG}"
                            TextElement.FontWeight="Bold"
                            ContentSource="Header" 
                            Margin="8,6"
                            RecognizesAccessKey="True" />
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsSelected" Value="True">
                            <Setter TargetName="Border" Property="BorderBrush" Value="{DynamicResource Brush.Accent1}"/>
                            <Setter TargetName="Border" Property="Opacity" Value="1"/>
                            <Setter TargetName="ContentSite" Property="TextElement.Foreground" Value="{DynamicResource Brush.Accent1}"/>
                        </Trigger>
                        <MultiTrigger>
                            <MultiTrigger.Conditions>
                                <Condition Property="IsSelected" Value="False"/>
                                <Condition Property="IsMouseOver" Value="True"/>
                            </MultiTrigger.Conditions>
                            <Setter TargetName="Border" Property="BorderBrush" Value="{DynamicResource Brush.Accent2}"/>
                        </MultiTrigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>