With custom CSS - us Firefox Inspector or one of the other browser developer tools to fine the CSS for one of the existing box variations and then duplicate that and change the styling to how you need.
You didn't say what template or Gantry version so I can't be any more specific.
Regards, Mark.
Please search forums before posting. Please make sure your post includes the version of the CMS you are using and a link to the problem. Annotations on screenshots can also be helpful to explain problems/goals. Please use the "secure" tab for confidential information.
Please search forums before posting. Please make sure your post includes the version of the CMS you are using and a link to the problem. Annotations on screenshots can also be helpful to explain problems/goals. Please use the "secure" tab for confidential information.