code: function font(size) {
      var cssText = selectors + '{ font-size: ' + size + 'px; }',
          el = document.createElement('style');
  
      el.type = 'text/css';
      if (el.styleSheet) {
        el.styleSheet.cssText = cssText;//IE only
      } else {
        el.appendChild(document.createTextNode(cssText));
      }
      head.appendChild(el);
    }
docs: via http://stackoverflow.com/questions/2041495/create-dynamic-inline-stylesheet