code: function fixGradient(str) {
    var ret = str.replace(GRADIENT_REPLACE_RE, function($0, $1, $2){
      return $1 ?
        $0 :
        ($2 == 'right') ?
          'left' :
          ($2 == 'left') ?
            'right' :
            (parseInt($2) % 180 == 0) ?
              $2 :
              ($2.substr(0,1) == '-') ?
                $2.substr(1) :
                ('-' + $2);
      });
    return ret;
  }
docs: Fixes most gradient definitions
  
  Replaces `left` with `right`, `X(X(X))deg` to `-X(X(X))deg`, and the opposites
  
  fixGradient("-webkit-gradient(linear, left bottom, right top, color-stop(0%,#000), color-stop(100%,#fff))")
  -> "fixGradient("-webkit-gradient(linear, right bottom, left top, color-stop(0%,#000), color-stop(100%,#fff))")"
  fixGradient("background: linear-gradient(45deg, #000 0%, #fff 100%)")
  -> "linear-gradient(-45deg, #000 0%,#fff 100%)"