This is light-weight responsive css library, forcegrid provides you barebone structure or skeleton to your responsive Force.com and HTML Apps.
Read detail on blog post
To learn more, go to http://mailtoharshit.github.io/ForceGrid/
Using ForceGrid is simple. First, link to forcegrid.css in your HTML document's header of your page:
<link rel="stylesheet" href="css/forcegrid.css">
If you are using CDN, then use this CDN genereated by RawGit
<link rel="stylesheet" href="https://rawgit.com/mailtoharshit/ForceGrid/master/source/forcegrid.css" />