WP PageNavi Styling Pagination Elements – with 2 and 3 digits bg img

I have this code in my functions.php:

[code moderated - see http://codex.wordpress.org/Forum_Welcome#Posting_Code ]

And I need to know what part of this do I need to use in my CSS to set a background image for pages 10-99 and 100-999 (set wider background image to contain the numbers)

Here is my CSS:

[CSS code removed - please post a link to your site]

And here is a current Screen Shot:

<img src="http://i43.tinypic.com/21vtrl.png"/>
http://i43.tinypic.com/21vtrl.png

10 and 100 will need a new CSS class

Thanks