DiffWindow.xaml

<Window x:Class="MultiDF.Views.DiffWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        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"
        xmlns:vm="clr-namespace:MultiDF.VM;assembly=MultiDF.VM"
        xmlns:local="clr-namespace:MultiDF.Views"
        mc:Ignorable="d"
        WindowStartupLocation="CenterScreen" ShowInTaskbar="False" WindowStyle="None" 
        Background="Transparent" AllowsTransparency="True"
        ResizeMode="NoResize" Width="700" SizeToContent="Height"
        DataContext="{x:Static vm:ViewModelLocator.Diff}"
        d:DataContext="{d:DesignInstance Type=vm:DiffVM, IsDesignTimeCreatable=True}">

  <Window.Resources>
    <ResourceDictionary>
      <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="pack://application:,,,/ViewsBase;component/Styles.xaml" />
      </ResourceDictionary.MergedDictionaries>

      <Style TargetType="Button" BasedOn="{StaticResource BlueButton}" />
    </ResourceDictionary>
  </Window.Resources>

  <Border CornerRadius="15" Background="White" BorderThickness="1" BorderBrush="#00aff0" Padding="6" Margin="12">
    <Border.Effect>
      <DropShadowEffect BlurRadius="12" ShadowDepth="10" Color="LightGray" />
    </Border.Effect>

    <Grid Margin="12">
      <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*" />
        <ColumnDefinition Width="*" />
      </Grid.ColumnDefinitions>
      <Grid.RowDefinitions>
        <RowDefinition Height="Auto" />
        <RowDefinition Height="*" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="*" />
        <RowDefinition Height="Auto" />
      </Grid.RowDefinitions>

      <Grid.Resources>
        <Style TargetType="TextBlock">
          <Setter Property="Margin" Value="3" />
          <Setter Property="VerticalAlignment" Value="Center" />
        </Style>
        <Style TargetType="TextBox">
          <Setter Property="Margin" Value="6" />
          <Setter Property="Padding" Value="3" />
        </Style>

        <local:DiffTypeToColorConverter x:Key="DiffTypeToColorConverter" />
        <local:SubPiecesOrTextConverter x:Key="SubPiecesOrTextConverter" />

        <DataTemplate x:Key="DiffDataTemplate">
          <ItemsControl ItemsSource="{Binding Converter={StaticResource SubPiecesOrTextConverter}}">
            <ItemsControl.ItemsPanel>
              <ItemsPanelTemplate>
                <WrapPanel />
              </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
            <ItemsControl.ItemTemplate>
              <DataTemplate>
                <TextBlock Text="{Binding Text}" Margin="0" Padding="0" TextWrapping="Wrap">
                  <TextBlock.Background>
                    <SolidColorBrush Color="{Binding Type, Converter={StaticResource DiffTypeToColorConverter}}" />
                  </TextBlock.Background>
                </TextBlock>
              </DataTemplate>
            </ItemsControl.ItemTemplate>
          </ItemsControl>
        </DataTemplate>
      </Grid.Resources>

      <TextBlock Text="Question" Grid.ColumnSpan="2" FontSize="16" FontWeight="Bold" />

      <ListBox Height="300" ItemsSource="{Binding Q1, Mode=OneWay}" Grid.Column="0" Grid.Row="1" FontFamily="Courier New" ItemTemplate="{StaticResource DiffDataTemplate}" ScrollViewer.HorizontalScrollBarVisibility="Disabled" />
      <ListBox Height="300" ItemsSource="{Binding Q2, Mode=OneWay}" Grid.Column="1" Grid.Row="1" FontFamily="Courier New" ItemTemplate="{StaticResource DiffDataTemplate}" ScrollViewer.HorizontalScrollBarVisibility="Disabled" />

      <TextBlock Text="Answer Choices" Grid.ColumnSpan="2" Grid.Row="2" FontSize="16" FontWeight="Bold" />

      <ListBox Height="300" ItemsSource="{Binding A1, Mode=OneWay}" Grid.Column="0" Grid.Row="3" FontFamily="Courier New" ItemTemplate="{StaticResource DiffDataTemplate}" ScrollViewer.HorizontalScrollBarVisibility="Disabled" />
      <ListBox Height="300" ItemsSource="{Binding A2, Mode=OneWay}" Grid.Column="1" Grid.Row="3" FontFamily="Courier New" ItemTemplate="{StaticResource DiffDataTemplate}" ScrollViewer.HorizontalScrollBarVisibility="Disabled" />

      <StackPanel Grid.ColumnSpan="2" Grid.Row="4" Orientation="Horizontal" HorizontalAlignment="Right" Margin="3,6">
        <Button x:Name="CloseButton" Content="Close" Click="CloseButton_Click" IsCancel="true" Margin="3,12" />
      </StackPanel>
    </Grid>

  </Border>
</Window>