MergedDictionaries can not be referenced from App.xaml - xaml

Question

My styles are separated in separate files for better organization and readability. All files are referenced in my App.xaml. Some styles are BasedOn other styles, so I have placed them in the proper order so that the inherited styles are loaded before the dependent ones. However, I am still getting the following error on my XAML views that reference a font style, for example...Cannot find a Resource with the Name/Key SourceSansPro-Light.
Can someone enlighten me on why this Name/Key cannot be found? Here's the relevant code.
App.xaml
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Common/Styles/StyleResources.xaml" />
<ResourceDictionary Source="Common/Styles/InputStyles.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
StyleResources.xaml
<ResourceDictionary.ThemeDictionaries>
<ResourceDictionary x:Key="Light">
<SolidColorBrush x:Key="TextBoxBackgroundBrush" Color="White"/>
</ResourceDictionary>
</ResourceDictionary.ThemeDictionaries>
<FontFamily x:Key="SourceSansPro-Light">../../Assets/Fonts/SourceSansPro-Light.otf#Source Sans Pro</FontFamily>
<Style x:Key="TextBlockStyle" TargetType="TextBlock" BasedOn="{StaticResource BaseTextBlockStyle}">
<Setter Property="FontSize" Value="18"/>
<Setter Property="FontFamily" Value="{StaticResource SourceSansPro-Semibold}" />
</Style>
InputStyles.xaml
<Style x:Key="SecondaryTextStyle" TargetType="TextBlock" BasedOn="{StaticResource TextBlockStyle}">
<Setter Property="FontFamily" Value="{StaticResource SourceSansPro-Light}"/>
</Style>
HomePage.xaml (where style, SourceSansPro-Light, is being called in this view)
<Page.Resources>
<Style x:Name="InfoBodyTextStyle" TargetType="TextBlock">
<Setter Property="FontFamily" Value="{StaticResource SourceSansPro-Light}"/>
</Style>

Answer 1

Please try this code.
<Style TargetType="TextBlock">
<Setter Property="Foreground" Value="#FF64CCEF"/>
<Setter Property="SnapsToDevicePixels" Value="True"/>
<Setter Property="FontFamily" Value="{DynamicResource FontFamilyResource}"/>
</Style>
<FontFamily x:Key="FontFamilyResource">/ApplicationName(SolutionName);component/Resources/Fonts/#Vladimir Script</FontFamily>