Change header space on individual post in Split Theme

Tom, quick question here on this one too:

In the split theme, on an individual post template, I see the grey backdrop which houses the Title of the post, "admin" and post date.

But then theres a huge gap between the header container and the actual blog content.

(1) How do I reduce the header container (ie with the Title of post/admin/post date) OR move UP the blog content, just to reduce all that white space between the two?

I've been fiddling with the containers section in the customize part of the theme, but can't seem to find the right toggle slider.

Thanks!
Kunal