SteamTools/System.Application.SteamTools.Client.Desktop.Avalonia/Application/UI/Controls/ToastMessage.axaml

<UserControl xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
             x:Class="System.Application.UI.Controls.ToastMessage">
    <Border Padding="10" Background="{DynamicResource ActiveBackgroundBrushKey}">
        <Panel>
            <TextBlock Text="Teset Message"></TextBlock>
        </Panel>
    </Border>
</UserControl>