Mesen2/UI/Styles/AvaloniaNumericUpDownStyles.xaml

<Styles
	xmlns="https://github.com/avaloniaui"
	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	xmlns:sys="clr-namespace:System;assembly=netstandard"
>
	<Design.PreviewWith>
		<Window Width="440" Height="620" Padding="5">
			<StackPanel>
				<NumericUpDown Value="1" />
				<NumericUpDown Value="1" Minimum="1" />
				<NumericUpDown Value="1" Maximum="1" />
				<NumericUpDown Value="100" IsEnabled="False" />
			</StackPanel>
		</Window>
	</Design.PreviewWith>
	
	<!-- NumericUpDown -->
	<Style Selector="NumericUpDown ButtonSpinner">
		<Setter Property="Template">
			<ControlTemplate>
				<Border Background="{TemplateBinding Background}"
							BorderBrush="{TemplateBinding BorderBrush}"
							BorderThickness="{TemplateBinding BorderThickness}"
							CornerRadius="{TemplateBinding CornerRadius}"
							MinHeight="{TemplateBinding MinHeight}">
					<DockPanel>
						<Border BorderThickness="1 0 0 0" BorderBrush="Gray" DockPanel.Dock="Right">
							<Grid Name="PART_SpinnerPanel" RowDefinitions="*,Auto,*"
											IsVisible="{TemplateBinding ShowButtonSpinner}">
								<RepeatButton Name="PART_IncreaseButton"
												  Grid.Row="0"
													BorderBrush="{TemplateBinding BorderBrush}"
													BorderThickness="0"
													VerticalAlignment="Stretch"
													VerticalContentAlignment="Center"
													Foreground="{TemplateBinding Foreground}"
													FontSize="{TemplateBinding FontSize}"
													MaxWidth="14"
													MinWidth="14"
										>
									<PathIcon
											Width="10"
											Margin="0 -2 0 0"
											Height="8"
											Data="{StaticResource ButtonSpinnerIncreaseButtonIcon}" />
								</RepeatButton>
								<Rectangle Fill="Gray" Height="1" Grid.Row="1" />
								<RepeatButton Name="PART_DecreaseButton" Grid.Row="2"
													BorderBrush="{TemplateBinding BorderBrush}"
													BorderThickness="0 0 0 0"
													VerticalAlignment="Stretch"
													VerticalContentAlignment="Center"
													Foreground="{TemplateBinding Foreground}"
													FontSize="{TemplateBinding FontSize}"
													MaxWidth="14"
													MinWidth="14"
										>
									<PathIcon
											Width="10"
											Margin="0 -1 0 0"
											Height="8"
											Data="{StaticResource ButtonSpinnerDecreaseButtonIcon}" />
								</RepeatButton>
							</Grid>
						</Border>
						<ContentPresenter Name="PART_ContentPresenter"
												Grid.Column="1"
												ContentTemplate="{TemplateBinding ContentTemplate}"
												Content="{TemplateBinding Content}"
												HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
												VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
												Padding="{TemplateBinding Padding}" />
					</DockPanel>
				</Border>
			</ControlTemplate>
		</Setter>
	</Style>
</Styles>