How to customize border and background of a textbox in a Universal Windows 10 app?
<p>I am developing a universal Windows 10 app. I want to customize a textbox to remove its default border hover and background.</p>

<p>My problem is that I do not know how to customize on the Universal Windows Platform.</p>

<p><strong>Here is the code that I am using:</strong></p>

<pre><code>&lt;Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"&gt;
    &lt;!--layoutroot where all page content is placed--&gt;
    &lt;Grid x:Name="layoutRoot" Background="#1BA1E2"&gt;
        &lt;Grid.RowDefinitions&gt;
            &lt;RowDefinition Height="Auto"/&gt;
            &lt;RowDefinition Height="*"/&gt;
        &lt;/Grid.RowDefinitions&gt;

        &lt;StackPanel Grid.Row="0" Margin="12,0,12,0"&gt;
            &lt;!--Title Page--&gt;
            &lt;TextBlock Text="Login Here" Foreground="White" FontSize="40" Padding="60,80,60,80"/&gt;

            &lt;!--username--&gt;
            &lt;Border CornerRadius="10" Background="Transparent" BorderBrush="White" BorderThickness="1" Margin="5"&gt;
                &lt;TextBox PlaceholderText="Username" Name="Username" Background="Transparent" BorderBrush="{x:Null}" GotFocus="Username_GotFocus"/&gt;
            &lt;/Border&gt;
            &lt;!--Password--&gt;
            &lt;Border CornerRadius="10" Background="Transparent" BorderBrush="White" BorderThickness="1" Margin="5"&gt;
                &lt;TextBox PlaceholderText="Password" Name="Password" Background="Transparent" BorderBrush="{x:Null}" GotFocus="Password_GotFocus"/&gt;
            &lt;/Border&gt;

            &lt;!--Button login--&gt;
            &lt;Border CornerRadius="10" Background="Transparent" BorderBrush="White" BorderThickness="1" Margin="5"&gt;
                &lt;TextBlock Text="Log In" Foreground="White" Margin="0" Padding="200,5,0,5"/&gt;
            &lt;/Border&gt;

        &lt;/StackPanel&gt;&lt;!--end StackPanel--&gt;
    &lt;/Grid&gt;&lt;!--end Grid layoutRoot--&gt;
&lt;/Grid&gt;
</code></pre>

<p><strong>Here is a screenshot of my UI problem:</strong></p>

<p>When I put the mouse pointer over a textbox, it changes the border and the background.</p>

<p><img src="https://i.stack.imgur.com/vny1n.png" alt="screenshot"></p>