sourcegit/src/Resources/Styles/ScrollViewer.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Style TargetType="{x:Type ScrollViewer}">
        <Setter Property="HorizontalScrollBarVisibility" Value="Auto"/>
        <Setter Property="VerticalScrollBarVisibility" Value="Auto"/>
        <Setter Property="Padding" Value="0"/>
        <Setter Property="BorderThickness" Value="0"/>
        <Setter Property="BorderBrush" Value="{DynamicResource Brush.Border1}"/>
        <Setter Property="SnapsToDevicePixels" Value="True"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ScrollViewer}">
                    <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
                        <Grid Background="{TemplateBinding Background}">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="*"/>
                                <RowDefinition Height="Auto"/>
                            </Grid.RowDefinitions>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*"/>
                                <ColumnDefinition Width="Auto"/>
                            </Grid.ColumnDefinitions>

                            <ScrollContentPresenter
                                Cursor="{TemplateBinding Cursor}"
                                Margin="{TemplateBinding Padding}"
                                ContentTemplate="{TemplateBinding ContentTemplate}"/>

                            <ScrollBar x:Name="PART_VerticalScrollBar"
                                     IsTabStop="False"
                                     Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}"
                                     Grid.Column="1" Grid.Row="0" Orientation="Vertical"
                                     ViewportSize="{TemplateBinding ViewportHeight}"
                                     Maximum="{TemplateBinding ScrollableHeight}"
                                     Minimum="0"
                                     Value="{TemplateBinding VerticalOffset}"/>

                            <ScrollBar x:Name="PART_HorizontalScrollBar"
                                     IsTabStop="False"
                                     Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}"
                                     Grid.Column="0" Grid.Row="1" Orientation="Horizontal"
                                     ViewportSize="{TemplateBinding ViewportWidth}"
                                     Maximum="{TemplateBinding ScrollableWidth}"
                                     Minimum="0"
                                     Value="{TemplateBinding HorizontalOffset}"/>
                        </Grid>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>