Sandbox Branding Solutions in SharePoint 2013

Sandbox Solutions have been deprecated in SharePoint 2013.  If I wanted to create a branding solution (WSP) using Visual Studio, so I can deploy/activate it in SharePoint Online (e.g. O365) I thought it would need to be a Sandbox solution.  If these have been deprecated what kind of solution should we be using - in my branding solution example? 

Thanks for any information the community can provide.