The border styles for replacing underlined links could be re-written like this:

border-bottom-style: solid;
border-width: 1px;

Then the border would pick up whatever colour’s already being used for links, without having to duplicate that value.

you can add an id of current (or something similar) in appropriate places in your navigation

I’ve used a strong or em element instead, so that there’s still some indication of the current page for screen readers and non-CSS folks..