Base is A super simple CSS Framework for building responsive websites that work well in all devices like smartphone, tablets, netbooks and desktop PC . With this framework you can built a responsive website for all devices big and small, base has got you covered.
It comes with custom styles for headings, tables, blockquotes forms, lists and more. There is a 960px (max), 12-column grid and it is created with screen readers in mind.
Works with screen readers in mind and has comes with JS fallbacks. Covers IE7+ and modern browsers such as Chrome, Firefox and Opera.
Website: http://matthewhartman.github.com/base/
Demo: http://matthewhartman.github.com/base/demo/
Download: https://github.com/matthewhartman/base/