I’m struggling to style a css drop down menu. I’ve looked at a few tutorials but I’m not quite getting there. Please look at this pen, [http://cdpn.io/yiKbo](http://cdpn.io/yiKbo “pen”). The aim is for the sub menu to be centred beneath its parent item. Also when hovering over a sub-menu item, the positioning of the sub menu is off.
I tried to follow a newish tutorial and amend the css values to fit my requirements but I don’t understand why nav ul ul is defined twice in the css and how to position the sub menu so it sits nicely centred under its parent item. Thanks for any help.