how to center block link button in product theme

Hi, I am using the product theme for another site im creating (i use it for every site - thank you tammie!) but i am having an issue with the link button on the blocks. if you go to you will see "block 3" has a link button under it's image, however the link is aligned left. how can i align the link center?

i tried attaching a screenshot but there is no section on this window to upload an image?