Breakpoints for sidebar

Hi.

First of all I want to thank you for a beautiful theme!

On my site I would like to change the breakpoint for the sidebar. At the moment the sidebar moves to the top at 992px. I would like this to happen sooner, at about 1200px.

I am working with a childtheme and I have tried to copy the parent theme’s media queries and make changes to the media queries in my own css file. However I cannot seem to change the breakpoints the way I would like.

I’m hoping you can give me some advice on how to continue ??