Default Theme Gallery Alignment issue

Hello there,

I need help for my website : http://www.mondobicire.it/

I’ve fixed the Body of the Theme ” Blanc ” setting the center alignment, since it was aligned to the left as a default setting.

But when you click on the images, the gallery is aligned to the right instead to the center.

You can check it here : http://www.mondobicire.it/prodotto/test-bici-1/

I need that the default gallery pops up in the Center and the black transparent background fill the missing spot on the left, when you click on the images.

So, what’s the CSS code to put in the Custom CSS in order to set the gallery in the center alignment ?

Thank you