Using Panels 3 on your Drupal 7 site? Is the fact that your site is stuck at 99% width driving you crazy? Don’t want to throw a width:100% !important; and some random panels generated class?
I stumbled acorss this nifty setting under Pages > Variants > Content > Canvas > Canvas Settings:
Uncheck this badboy and you should be good to go.
Happy drupaling.