Categories Plus Latest Layout How to Use Full Screen Width?

I’m trying to make the Categories + Latest view on desktop use the full available screen width.

Everything else on the site can remain the same — I only want this one layout (categories on the left, latest topics on the right) to expand to full width instead of staying in a fixed-width centered column.

I’ve tried overriding many elements’ containers (.wrap, .container, #main-outlet, etc.), but this specific view still stays restricted, so I believe there is another wrapper or grid controlling its width.

Could someone point me to the correct CSS that controls the width of the Categories + Latest layout?

Thank you.