text: (function (document) {
    var metas = document.getElementsByTagName("meta"),
      changeViewportContent = function (content) {
        for (var i = 0; i < metas.length; i++) {
          if (metas[i].name == "viewport") {
            metas[i].content = content;
          }
        }
      },
      initialize = function () {
        changeViewportContent(
          "width=device-width, minimum-scale=1.0, maximum-scale=1.0"
        );
      },
      gestureStart = function () {
        changeViewportContent(
          "width=device-width, minimum-scale=0.25, maximum-scale=1.6"
        );
      },
      gestureEnd = function () {
        initialize();
      };
  
    if (navigator.userAgent.match(/iPhone/i)) {
      initialize();
  
      document.addEventListener("touchstart", gestureStart, false);
      document.addEventListener("touchend", gestureEnd, false);
    }
  })(document);
  