Make right column flush with right container edge on all pages.

I have been playing with your new column features. I want to make the right column flush with the right container edge, eliminating the “right white box” on the attached sample page. I have created a child theme and modified the .content, .sidebar top and bottom paddings, but cannot figure out the right selectors for the containers.

Note that a 1 x 2 gallery aligns this just like I would like.

Thanks much.