InkForge/app/InkForge.Common/App.axaml

<Application xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             x:Class="InkForge.Common.App"
             RequestedThemeVariant="Default">
    <!-- "Default" ThemeVariant follows system theme variant. "Dark" or "Light" are other available options. -->

    <Application.Styles>
        <FluentTheme />
        <StyleInclude Source="avares://Avalonia.Controls.DataGrid/Themes/Fluent.xaml"/>
    </Application.Styles>
</Application>