rainmeter-studio/RainmeterStudio/UI/App.xaml

<Application x:Class="RainmeterStudio.UI.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Styles/Common.xaml" />
            </ResourceDictionary.MergedDictionaries>

            <Style TargetType="ToolBar">
                <Setter Property="Background" Value="Transparent" />
            </Style>
            <Style TargetType="ToolBarTray">
                <Setter Property="Background" Value="Transparent" />
            </Style>
            
            <Style x:Key="CommandMenuItemStyle" TargetType="MenuItem">
                <Setter Property="Command" Value="{Binding}" />
                <Setter Property="Header" Value="{Binding DisplayText}" />
                <Setter Property="ToolTip" Value="{Binding ToolTip}" />
                <Setter Property="InputGestureText" Value="{Binding ShortcutText}" />
            </Style>
            
            <Style x:Key="CommandButtonStyle" TargetType="ButtonBase">
                <Setter Property="Command" Value="{Binding}" />
                <Setter Property="ToolTip" Value="{Binding ToolTip}" />
                <Style.Triggers>
                    <Trigger Property="IsEnabled" Value="False">
                        <Setter Property="Opacity" Value=".5" />
                    </Trigger>
                </Style.Triggers>
            </Style>

            <Style x:Key="CommandAutoHideButtonStyle" TargetType="ButtonBase" BasedOn="{StaticResource CommandButtonStyle}">
                <Style.Triggers>
                    <Trigger Property="IsEnabled" Value="False">
                        <Setter Property="Visibility" Value="Collapsed" />
                    </Trigger>
                </Style.Triggers>
            </Style>

        </ResourceDictionary>
    </Application.Resources>
</Application>