I'm having a hard time explaining this, so bear with me. Does anyone know of a way to highlight the center-most list item? By that I mean the item that is at the middle of the browser when a user is scrolling. As they continue to scroll, the next item highlights as it scrolls into the center.

I've set up a codepen here: http://codepen.io/realph/pen/iucgL

Edit: Similar to something like this I guess. Try scrolling on that site to see what I mean.

Any help would be appreciated.

Thanks in advance.