WP Gallery how to adjust the margin on the results page

The plugin is not in the list so I do not have the option to enter it. It is WP Gallery plugin (Rocket)

I display book covers in the gallery of my Wordpress site. When you click on the book cover a page appears with information you have entered in the form provided in the Gallery. The text appears with no margin or padding. You have the ability to change the color and size but not the margin. I also need it done globally on my site. How can I achieve this action.

Here is an example http://ebookshost.org/childrens/ click the book cover to have the page appear.

Thank you,