Style the text input box in admin area

On my WP site some of the posts will have to be done using <pre>. This is because the blog owner wants to be able to make shapes with the words and the way they achieve this is just by using spaces. So it would be a bit like this:

    So this would
    be a        box
    with            a
    hole           in
    it  if you see my

That has helped me go on to style the individual posts using CSS on the <pre> tag so I have made it a bit smaller and a bit condensed. The problem with that is that the page doesn’t look like the text in the entry panel. Can I style them the same?