参考：https://www.jianshu.com/p/b00cd3506782
1、简易版rem布局（375px的设计稿，其实一般来说应该是750）
2、图片不缓存
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="viewport" content="width=device-width,minimum-scale=1.0,maximum-scale=1.0,user-scalable=no">
<title>简易版rem布局</title>
</head>
<body>
<div class="box">
<div class="content">
<div class="title">
<div class="logo"></div>
<div class="version">版本号：V1.6</div>
</div>
<div class="code-box ios-code-box">
<div class="ios-tag tag"></div>
<img id="iosCode" alt="">
</div>
<div class="code-box and-code-box">
<div class="and-tag tag"></div>
<img id="andCode" alt="">
</div>
</div>
</div>
<script>
(function (doc, win) {
var docEl = doc.documentElement,
resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
recalc = function () {
var clientWidth = docEl.clientWidth;
if (!clientWidth) return;
if(clientWidth>1024){
docEl.style.fontSize = '100px';
docEl.style.paddingTop = '20px'
}else{
docEl.style.fontSize = 100 * (clientWidth / 375) + 'px';
}
};
win.addEventListener(resizeEvt, recalc, false);
doc.addEventListener('DOMContentLoaded', recalc, false);
var ios = document.querySelector('#iosCode')
var and = document.querySelector('#andCode')
ios.setAttribute('src', 'ios-code.png?time=' + (new Date().getTime()))
and.setAttribute('src', 'and-code.png?time=' + (new Date().getTime()))
})(document, window);
</script>
</body>
</html>
