Zero Point

Zero Point is an advanced responsive, "mobile first", HTML5 theme, with layout and style configuration options built in that you can control through Drupal's UI. It uses Yahoo Pure.css, a powerful responsive CSS framework and also fully supports right to left languages. Pure is ridiculously tiny. The entire set of modules clocks in at 4.0KB minified and gzipped.

The theme validates HTML5, it is cross-browser compatible (including IE6), and it passes WAVE and FAE. 7.x-4.x is a complete redesign made with mobile in mind: compatible, light and fast.