In attempting to duplicate the look of a ZCv1.2.5 cart on a ZCv1.3.02 cart

I'm trying to get an image in the upper/center of my index page

I edited english/index.php "Congratulations you've successfully installed..." and replaced it with an image define('HEADING_TITLE', '<img src="/images/xxxx.jpg" alt="xxx" />');

and

centered it in my stylesheet:
.centerColumn,
text-align: center;

looks fine, but now of course all the text from everything else is showing centered which I don't want. I wouldn't mind the heading text centered as long as the body text was aligned left...

not really sure how I did it before, but now that the Plainbox is gone I'm looking for an alternative way to have an image on the index page at the top and center of the centerColumn or what ever that area may be called.

ideas?