# File lib/nokogiri/xml/node.rb, line 135
      def css *rules
        # Pop off our custom function handler if it exists
        handler = ![
          Hash, String, Symbol
        ].include?(rules.last.class) ? rules.pop : nil

        ns = rules.last.is_a?(Hash) ? rules.pop : document.root.namespaces

        rules = rules.map { |rule|
          CSS.xpath_for(rule, :prefix => ".//", :ns => ns)
        }.flatten.uniq + [ns, handler].compact

        xpath(*rules)
      end