FModel/FModel/Views/CustomDir.xaml

<adonisControls:AdonisWindow x:Class="FModel.Views.CustomDir"
                             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                             xmlns:converters="clr-namespace:FModel.Views.Resources.Converters"
                             xmlns:adonisUi="clr-namespace:AdonisUI;assembly=AdonisUI"
                             xmlns:adonisControls="clr-namespace:AdonisUI.Controls;assembly=AdonisUI"
                             xmlns:adonisExtensions="clr-namespace:AdonisUI.Extensions;assembly=AdonisUI"
                             WindowStartupLocation="CenterScreen" ResizeMode="NoResize" IconVisibility="Collapsed" SizeToContent="Height"
                             MinHeight="{Binding Source={x:Static SystemParameters.MaximizedPrimaryScreenHeight}, Converter={converters:RatioConverter}, ConverterParameter='0.20'}"
                             Width="{Binding Source={x:Static SystemParameters.MaximizedPrimaryScreenWidth}, Converter={converters:RatioConverter}, ConverterParameter='0.25'}">
    <adonisControls:AdonisWindow.Style>
        <Style TargetType="adonisControls:AdonisWindow" BasedOn="{StaticResource {x:Type adonisControls:AdonisWindow}}" >
            <Setter Property="Title" Value="Custom Directory" />
        </Style>
    </adonisControls:AdonisWindow.Style>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>

        <StackPanel Grid.Row="0" Orientation="Vertical" Margin="10 5 10 10">
            <TextBlock Text="What is this?" HorizontalAlignment="Center" FontSize="20" FontWeight="SemiBold" />
            <TextBlock TextAlignment="Center" TextWrapping="Wrap" HorizontalAlignment="Center"
                       Text="Bored of opening folders? Save custom directories to quickly jump to your favorite folder. They are saved according to your current set game, so don't freak out too fast." />
        </StackPanel>
        
        <GroupBox Grid.Row="1" adonisExtensions:LayerExtension.Layer="2" Margin="10 10 10 18"
                  Padding="{adonisUi:Space 0}" Background="Transparent">
            <Grid Margin="0 5">
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="5" />
                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="10" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>

                <TextBlock Grid.Row="0" Grid.Column="0" Text="Header" VerticalAlignment="Center" />
                <TextBox x:Name="WpfSuckMyDick" Grid.Row="0" Grid.Column="2" Text="{Binding Header, Mode=TwoWay}" />
                <TextBlock Grid.Row="2" Grid.Column="0" Text="Directory" VerticalAlignment="Center" />
                <TextBox Grid.Row="2" Grid.Column="2" Text="{Binding DirectoryPath, Mode=TwoWay}" />
            </Grid>
        </GroupBox>

        <Border Grid.Row="2"
                Background="{DynamicResource {x:Static adonisUi:Brushes.Layer1BackgroundBrush}}"
                adonisExtensions:LayerExtension.IncreaseLayer="True">
            <Grid Margin="30, 12, 6, 12">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition Width="Auto"/>
                    <ColumnDefinition Width="Auto"/>
                </Grid.ColumnDefinitions>

                <Button Grid.Column="1" MinWidth="78" Margin="0 0 12 0" IsDefault="True" IsCancel="False"
                        HorizontalAlignment="Right" VerticalAlignment="Bottom" Content="OK" Click="OnClick" />
                <Button Grid.Column="2" MinWidth="78" Margin="0 0 12 0" IsDefault="False"  IsCancel="True"
                        HorizontalAlignment="Right" VerticalAlignment="Bottom" Content="Cancel" />
            </Grid>
        </Border>
    </Grid>
</adonisControls:AdonisWindow>