Annoying area at bottom of screen

[WriterAndrew]

I'm currently building a docs portal using a Top-Nav format.

However, no matter what height settings I use across all my style sheets and skins, the pages always have a vertical scroll bar, as the "page" is always taller than the browser window.

Using the Chrome Dev Tools, it appears that the problematic area at the bottom of the page is a div.off-canvas-content.inner-wrap, however, nothing I do seems to influence this 6ish mm bar across the bottom of the screen.

Any suggestions on how I can make my default page fit the browser window?

Thanks