ViewController中的UINavigationController，视图顶部的间隙

I'm working on a universal app, and I'm trying to share as much code as possible between the iPhone and iPad versions. I need to use a TabBarController as my root view controller and though I'd like to use a SplitViewController in each of the tabs, SplitViewController's docs say it needs to be the root view controller. So, with all of that in mind - understand that I'm attempting to place two navigation controllers side-by-side and (mostly) replicate the behavior/layout of a SplitViewController.I'm working on a universal app, and I'm trying