Hi

I am try to customize the theme but I am encountering a problem. I want to change some things like the background color of the second sidebar & probably add a background, but cannot make out which style to change. I thought it is l/themes/zircon/css/page.css & the element "#sidebar-second-wrapper", but if I add any changes, they do not show at the frontend.

So my question is which style script & element are responsible for this and other changes?

Thank you in advance.