Example

I want to have in "HD" resolutions (>1000px width)
|----content----| |-sidebar1-| |-sidebar2-|

"Tablet" resolutions (~800-1000px width)
|----content----| |-sidebar1-|
|----------sidebar2------------|

Mobile resolutions (<800px width)
|----content----|
|----sidebar1---|
|----sidebar2---|

Omega can do "HD" and "Mobile", but not "Tablet". AT themes have this in the settings page.

What is the best way (most Omega way) to do theme setting which adapts to some medium sized screens?

Thank you.