Cogito is an HTML5 Drupal theme based on the foundation framework.
It is designed to make the design workflow easier by providing a standardized CSS framework (Foundation, by ZURB) and building on top of it using child themes. Very often entire themes can be accomplished in less than a page of CSS.
IE6-11 conditional stylesheets now supported:
Simply add a file named "ie6.css" in your child theme's root and it will be used conditionally. Works for ie6, ie7, ie8, ie9, ie10 and ie11 (and maybe by ie11 we won't need different stylesheets anymore)
We have a wordpress version too. you can see it here. You should be able to use stylesheets interchangeably between Wordpress and Drupal sites.