Responsive grid problem

Hi,

great plugin! I have only a very small issue. When I reduce my browser width the number of columns reduces automatically which is fine. But in the last cell the logos are not within the grid but centered in the cell.

How can I have the logos within the grid like in the cells above ?

Thanks for your help.
See screenshot here: http://s000.tinyupload.com/index.php?file_id=11611542078978579537

Here’s the site: http://bit.ly/1R4H8Kz

https://ww.wp.xz.cn/plugins/wp-logo-showcase-responsive-slider-slider/