How do you fix the Silverlight application bias that occurs in Firefox?

Question

Currently, I have a Silverlight application that, when launched in the Firefox browser (version 3.6), the entire contents of the Silverlight application changes slightly, as well as the scroll bars both below and from the side appear on first use. This does not happen in IE 8. How can I fix this in Firefox to prevent this from happening? The type of project I created was "Silverlight 3 Application + Website" through Expression Blend 3. This code I use in my MainPage.xaml:

<UserControl
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 x:Class="StackoverflowExample.MainPage"
 Width="640" Height="480">

 <Grid x:Name="LayoutRoot" Background="Green">
  <Rectangle Fill="#FFBB2020" Stroke="Black" Margin="155,58,266,178"/>
  <Button Margin="199,180,302,236" Content="Button"/>
 </Grid>
</UserControl>

Answer 1

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: focus {    : 0; }

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