动态像素比，动态字体设置

var pixclPatio = 1 / window.devicePixelRatio;
document.write(‘<meta name="viewport" content="width=device-width,initial-scale=‘+pixclPatio+‘,minimum-scale=‘+pixclPatio+‘,maximum-scale=‘+pixclPatio+‘,user-scalable=no" />‘);
            
var html = document.getElementsByTagName(‘html‘)[0];
var pageWidth = html.getBoundingClientRect().width;
            html.style.fontSize = pageWidth / 16 + ‘px‘;