Shaker/Avalonia/SukiUI/Theme/MenuFlyoutPresenter.axaml

<ResourceDictionary xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <ControlTheme x:Key="SukiMenuFlyoutPresenterStyle" TargetType="MenuFlyoutPresenter">
        <Setter Property="Background" Value="{DynamicResource SukiCardBackground}" />
        <Setter Property="CornerRadius" Value="6" />
        <Setter Property="BorderBrush" Value="{DynamicResource SukiMenuBorderBrush}" />
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="Template">
            <ControlTemplate>
                <Panel Margin="1,0,0,0">
                    <Border Margin="16"
                            BoxShadow="{DynamicResource SukiPopupShadow}"
                            CornerRadius="{TemplateBinding CornerRadius}" />
                    <Border Margin="15"
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            ClipToBounds="True"
                            CornerRadius="{TemplateBinding CornerRadius}">
                        <Panel Background="{DynamicResource PopupGradientBrush}">
                            <ItemsPresenter Name="PART_ItemsPresenter"
                                            HorizontalAlignment="Left"
                                            VerticalAlignment="Center"
                                            ItemsPanel="{TemplateBinding ItemsPanel}"
                                            KeyboardNavigation.TabNavigation="Continue" />
                        </Panel>
                    </Border>
                </Panel>
            </ControlTemplate>
        </Setter>
        <Style Selector="^ /template/ MenuItem">
            <Setter Property="Padding" Value="10,0,0,0" />
        </Style>
    </ControlTheme>
    <ControlTheme x:Key="{x:Type MenuFlyoutPresenter}"
                  BasedOn="{StaticResource SukiMenuFlyoutPresenterStyle}"
                  TargetType="MenuFlyoutPresenter" />
</ResourceDictionary>