Centering category images in a Joomla article

[ben1265]

I have a Joomla article and would like to display images from a Phoca Gallery. The version of the Plugin is 6.1.1. The problem is that the image grid is left aligned, which is not very attractive. I want the grid to be centered. I have played with CSS to achieve this but I haven't gotten anywhere.
It seems to ne having the image grid centered would be what most people would want. Is that not possible using the Phoca Gallery plugin?