ClassicAssist.Avalonia/ClassicAssist/Resources/ResourceDictionary.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:controls="clr-namespace:ClassicAssist.UI.Controls">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="DarkTheme.xaml" />
    </ResourceDictionary.MergedDictionaries>
</ResourceDictionary>