Footer Divider

Hey everyone,

I’m trying to change my current footer’s item divider from a simple 1px line to a 2px “pressed style” line where the line on top is e.g. #999 and the bottom line is e.g. #FFF.

Could anyone tell me what and where I need to add into the theme’s style.css in order to realize this?

Here is a screenshot of my current footer with the 1px divider:
https://imageshack.us/photo/my-images/100/show1.png/

And here of what I am trying to do:
https://imageshack.us/photo/my-images/191/show2l.png/

Could anyone help me out?

Thanks