I'm trying to integrate a sliding "featured posts" thing into my design. It'll have left and right arrows for navigation on each side.

I don't understand how to make the arrows automatically hide when the browser width gets too low. For example: Droid-Life. There featured bar is similar to the one I want to create. When my browser viewport is small, the arrows on each side go away. When I make it wide enough, they come into view.

How can I achieve this effect?