OnlineMonitorSystem/HandyControl/HandyControl_Shared/Themes/Styles/Menu.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <Style BasedOn="{StaticResource MenuItemBaseStyle}" TargetType="MenuItem" />

    <Style BasedOn="{StaticResource MenuBaseStyle}" TargetType="Menu" />

    <Style x:Key="Menu.Small" BasedOn="{StaticResource MenuBaseStyle}" TargetType="Menu">
        <Setter Property="hc:MenuAttach.ItemPadding" Value="6,0" />
        <Setter Property="hc:MenuAttach.PopupVerticalOffset" Value="-3" />
        <Setter Property="hc:MenuAttach.PopupHorizontalOffset" Value="6" />
    </Style>

</ResourceDictionary>