WIn_RustTools/RustTools/Styles/TitleSubtitleControlStyle.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:RustTools.Styles">
    <Style x:Key="TitleSubtitleControlStyle" TargetType="local:TitleSubtitleControl">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="local:TitleSubtitleControl">
                    <StackPanel
                        Margin="16,0,16,0"
                        Padding="3"
                        HorizontalAlignment="Center"
                        VerticalAlignment="Center">
                        <TextBlock
                            HorizontalAlignment="Center"
                            Style="{StaticResource SubtitleTextBlockStyle}"
                            Text="{TemplateBinding TitleText}" />
                        <TextBlock
                            HorizontalAlignment="Center"
                            Style="{StaticResource BodyStrongTextBlockStyle}"
                            Text="{TemplateBinding SubtitleText}" />
                    </StackPanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>