Removing Blank Space between widgets

This plug in is just fantastic !!! Thanks for your time to create this.

I am just trying to tweak one last thing, and can’t find the css to do it.

Between widgets there is a lot of blank space I would like to remove. For example, with the link below, I’d like to remove the blank space between the Buy Prints/Request Image Quote buttons, and the next section of Newsletter & Photo Tips Signup.

http://shetzers.com/category/photography-blog/

I’ve tried Googles developers tools, but can’t seem to locate the css. I’d love to know how it can be found out.

Thanks again !
Matt

https://wordpress.org/plugins/posts-in-sidebar/