AutoCompleteTextBox.xaml

<TextBox x:Class="Upsilon.Apps.Passkey.GUI.WPF.Views.Controls.AutoCompleteTextBox"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:Upsilon.Apps.Passkey.GUI.WPF.Views.Controls"
             mc:Ignorable="d">
    <TextBox.Style>
        <Style TargetType="TextBox">
            <Setter Property="Background" Value="{StaticResource SecondaryBackgroundBrush}"/>
            <Setter Property="Foreground" Value="{StaticResource ForegroundBrush}"/>
            <Setter Property="BorderBrush" Value="{StaticResource BorderBrush}"/>
            <Setter Property="Margin" Value="5"/>
            <Setter Property="VerticalContentAlignment" Value="Center"/>
            <Setter Property="FontFamily" Value="Courier New"/>
        </Style>
    </TextBox.Style>
</TextBox>