<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
//这一行保证屏幕不能缩放
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0"/>
<title></title>
</head>
<body>
<script src="js/jquery3.3.1.js"></script>
<script type="text/javascript">
(function(){
/*rem适配*/
var html = document.documentElement;//获取根节点
var width = html. ().width; //屏幕的设备独立像素
html.style.fontSize = width/15 + "px";
//iphone5 320*568 则 fontSize为20px 也就是说 1rem=20px
})();
</script>
</body>
</html>