    # File lib/active_support/vendor/builder-2.1.2/builder/css.rb, line 171
        def method_missing(sym, *args, &block)
          sym = "#{sym}:#{args.shift}" if args.first.kind_of?(Symbol)
          if block
            _start_container(sym, args.first)
            _css_block(block)
            _unify_block
          elsif @in_block
            _indent
            _css_line(sym, *args)
            _newline
            return self
          else
            _start_container(sym, args.first, false)
            _unify_block
          end
          self
        end