How to center gallery on page

Hi,

I am using WP 4.7, Twenty Thirteen theme and am having an issue with my Carousel Galleries.
As you can see here (https://www.freemovin.com/index.php/2016-trash-trophies/), the gallery is not centered on the page. I have tried to edit my child theme CSS with no success.
Is it something that is possible to do ?

Thanks