Avalonia/src/Avalonia.Themes.Fluent/Controls/Carousel.xaml

<Style xmlns="https://github.com/avaloniaui" Selector="Carousel">
  <Setter Property="Template">
    <ControlTemplate>
      <Border Background="{TemplateBinding Background}"
              BorderBrush="{TemplateBinding BorderBrush}"
              BorderThickness="{TemplateBinding BorderThickness}"
              CornerRadius="{TemplateBinding CornerRadius}">
        <CarouselPresenter IsVirtualized="{TemplateBinding IsVirtualized}"
                           Items="{TemplateBinding Items}"
                           ItemsPanel="{TemplateBinding ItemsPanel}"
                           Margin="{TemplateBinding Padding}"
                           SelectedIndex="{TemplateBinding SelectedIndex}"
                           PageTransition="{TemplateBinding PageTransition}"/>
      </Border>
    </ControlTemplate>
  </Setter>
</Style>