Help with sidebar bg colour inconsistency?

Here’s an image showing more or less what I’m trying to do.

There are legacy text entry widgets in the sidebar, and I’d like not to have great big white rectangles there. I’ve tried adding background: black in various places but so far have only succeeded in altering the text box itself.

Can any css savvy person tell me at which level of nesting I would need to intervene and with what syntax? Obviously I’m not expert at this, just inheriting someone else’s layout and trying to fix a thing or two here and there.

• This topic was modified 2 years, 4 months ago by tazling.

The page I need help with: [log in to see the link]