title: blurred opacity
body: <p>I need to create a transparent blurred background. Lets suppose I have a border with a white blurry transparent background. Everything that is behind the border is blurred.</p>
  
  <p>I'm trying to avoid dependencies; I'm currently using .NET 3.0, and want it to run with XP too.</p>
  
  <p>Mockup image:</p>
  
  <p><img src="https://i.stack.imgur.com/rmKkp.png" alt="Mockup Image"></p>