PowerToys/src/modules/Workspaces/WorkspacesLauncherUI/App.xaml

<Application
    x:Class="WorkspacesLauncherUI.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:WorkspacesLauncherUI"
    Exit="OnExit"
    Startup="OnStartup"
    ThemeMode="System">
    <Application.Resources>
        <ResourceDictionary>
            <FontFamily x:Key="SymbolThemeFontFamily">Segoe Fluent Icons, Segoe MDL2 Assets</FontFamily>
            <Style x:Key="HeadingTextBlock" TargetType="TextBlock" />
            <Style
                x:Key="SubtleButtonStyle"
                BasedOn="{StaticResource {x:Type Button}}"
                TargetType="Button">
                <Setter Property="Background" Value="Transparent" />
                <Setter Property="BorderBrush" Value="Transparent" />
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="Button">
                            <Border
                                x:Name="Border"
                                Padding="{TemplateBinding Padding}"
                                Background="{TemplateBinding Background}"
                                BorderBrush="{TemplateBinding BorderBrush}"
                                BorderThickness="{TemplateBinding BorderThickness}"
                                CornerRadius="4"
                                SnapsToDevicePixels="True">
                                <ContentPresenter
                                    HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                    VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                                    Focusable="False"
                                    RecognizesAccessKey="True"
                                    SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
                            </Border>
                            <ControlTemplate.Triggers>
                                <Trigger Property="IsMouseOver" Value="True">
                                    <Setter TargetName="Border" Property="Background" Value="{DynamicResource SubtleFillColorSecondaryBrush}" />
                                    <Setter TargetName="Border" Property="BorderBrush" Value="{DynamicResource SubtleFillColorSecondaryBrush}" />
                                </Trigger>
                                <Trigger Property="IsPressed" Value="True">
                                    <Setter TargetName="Border" Property="Background" Value="{DynamicResource SubtleFillColorTertiaryBrush}" />
                                    <Setter TargetName="Border" Property="BorderBrush" Value="{DynamicResource SubtleFillColorTertiaryBrush}" />
                                    <Setter Property="Foreground" Value="{DynamicResource TextFillColorSecondaryBrush}" />
                                </Trigger>
                                <Trigger Property="IsEnabled" Value="False">
                                    <Setter Property="Foreground" Value="{DynamicResource TextFillColorDisabledBrush}" />
                                </Trigger>
                            </ControlTemplate.Triggers>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </ResourceDictionary>
    </Application.Resources>
</Application>