var baseW = 980;
var baseSP = 767;
var iOSviewportW = 0;
var ua = navigator.userAgent.toLowerCase();
var isiOS = (ua.indexOf("iphone") > -1) || (ua.indexOf("ipod") > -1) || (ua.indexOf("ipad") > -1);
if(isiOS){
	iOSviewportW = document.documentElement.clientWidth;
}
function updateMetaViewport(){
	var viewportContent;
	var w = window.outerWidth;
	if(isiOS){
		w = iOSviewportW;
	}
	if(w < baseW && w > baseSP){
		viewportContent = "width="+baseW+"px,initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no, shrink-to-fit=no";
	}if(w < baseSP){
		viewportContent = "width=device-width,initial-scale=1";
	}else{
		viewportContent = "width=device-width,initial-scale=1";
	}
	document.querySelector("meta[name='viewport']").setAttribute("content", viewportContent);
}



//イベントハンドラ登録
document.addEventListener('touchstart', event => {
  if (event.touches.length > 1) {
    event.preventDefault();
  }
}, true);
let lastTouch = 0;
document.addEventListener('touchend', event => {
  const now = window.performance.now();
  if (now - lastTouch <= 500) {
    event.preventDefault();
  }
  lastTouch = now;
}, true);