My understanding is that because Twenty Twelve only comes in a “Boxed” layout without a built-in option to make it a full width “Fluid” layout (i.e. edge to edge in your browser), making changes to the css won’t be enough to override the page template. I could be wrong, but I think you will need to modify the built-in page templates or make a new custom one to get the result you’re looking for.
I’m hoping one of the Beaver Builder support team has an easier way for you, though:)
Colin is right in that Twenty Twelve is strictly a boxed layout theme. You would need to do some theme modification in order to make it full width which would probably be more work than it is worth. I would recommend using a theme that is full width out of the box. It appears you have the Pro version of our product which comes with the Beaver Builder theme. The BB theme can be full width if desired with ease. Let me know if I can assist further and thanks again!
Very cool, glad that worked for you and thanks for letting us know! I am assuming you have zeroed out the left/right padding already on your rows/modules. Have you accessed the global settings for Beaver Builder to turn off the global 20px padding by chance? That can be accessed via the Tools button > Global Settings while in editing mode. If that doesn’t work for you, would you mind sending along temp credentials so I can take a look for you?
This is a bit beyond what we support in here, but the selector you will want to apply the 0 left/right padding rules would be ‘.fl-builder’ before your other selectors.