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

    <x:Double x:Key="LargeFontSize">24</x:Double>
    <x:Double x:Key="MediumFontSize">16</x:Double>

</ResourceDictionary>
