路径：和main.js平级的lib文件夹里

./lib/rem.js

html" title=javascript>javascript">let resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize';
let recalc = function () {
    let width = document.documentElement.clientWidth;
    if (width < 1920) {
        width = 1920;
    }
    let point = 12 / 1920;
    let FontSize = point * width;
    document.documentElement.style.fontSize = FontSize + 'px';
    window.REMFontSize = FontSize;
}

window.addEventListener(resizeEvt, recalc, false);
document.addEventListener('DOMContentLoaded', recalc, false);

在main.js 引入

html" title=javascript>javascript">import './libs/rem'

cssrem_22">在项目根目录加上 .cssrem文件，内容如下

html" title=javascript>javascript">{
  "rootFontSize": 12,
  "fixedDigits": 3
}