Navigation styling help

I am having trouble with my navigation menu, I have some li that are floated left of each other, and each li has a back ground image set to the right to give a seperation effect, within the li I have a a that is text aligned center.

On hover I have a bottom-border but I need said board to span the fu开发者_如何学JAVAll width of the li not the a is this possible?

Here is a fiddle of my current attempt,

Fiddle

The following CSS should do the trick:

header nav a { width:100%; }