Styling Images

Hello!)

I installed the plugin and I love the way it works.
The only problem I have is that i want to change the spacing/padding between the images so it would look like this:
http://sm-web.ru/photos/index.html

I tried to play with css but nothing seem to work.
Can you help me out?
the website is:
http://photorush.ru/

Thanks!

https://ww.wp.xz.cn/plugins/jquery-masonry-image-gallery/