Windows Explorer-like search box on Aero glass frame with WPF

This is my attempt to recreate the look of the Windows Explorer search box in WPF:

It doesn't look 100% like the original, but it's pretty close.

Here's the code:

<Border BorderBrush="#40FFFFFF" BorderThickness="1" CornerRadius="2">
  <Border BorderBrush="#80000000" BorderThickness="1,1,0,0" CornerRadius="2">
    <Border BorderBrush="#30000000" BorderThickness="0,0,1,1" CornerRadius="2">
      <Border BorderBrush="#F0FFFFFF" BorderThickness="1" CornerRadius="1">
        <TextBox Background="#C0FFFFFF" BorderThickness="0"></TextBox>
      </Border>
    </Border>
  </Border>
</Border>