Another day another 5 CSS snippets to share that you can use for NextGEN Gallery, Plus and Pro. To see more CSS snippets, look here.
To use any of this custom CSS please go to NextGEN Gallery >> Other Options >> Styling. From there, make sure custom styling is turned on and then the custom CSS block will display.
Any custom CSS you place in this block (and save) is upgrade proof. That means the custom CSS will remain each time you update so you do not have to think about redoing it.