Conditional Tags and Date Modified

I’d like to display a list of the three most recently modified posts, and if the modified date of a post is also today‘s date, I’d like to apply a different CSS class. (so that I can alter how it looks, making it more obvious that it’s a brand new version of a post.) I looked through the Conditional Tags article in the documentation, but couldn’t find the “if” statement that tied those two factors (the modified date and today’s date) together.

Thanks!