code: func (inliner *Inliner) inlineStyleRules() error {
  	for _, element := range inliner.elements {
  		// remove marker
  		element.elt.RemoveAttr(eltMarkerAttr)
  
  		// inline element
  		err := element.inline()
  		if err != nil {
  			return err
  		}
  	}
  
  	return nil
  }
docs: // Inline style rules in HTML document