const AutoPrefixer = require("autoprefixer"); const px2rem = require("postcss-px2rem"); module.exports = ({ file }) => {   let remUnit;   // 判断条件 请自行调整 我使用的是 mand-mobile ui 没有对vant引入进行测试   //link https://github.com/youzan/vant/issues/1181   if (file && file.dirname && file.dirname.indexOf("vant") > -1) {     remUnit = 37.5;   }else {     remUnit = 75;   }   return {     plugins: [      px2rem({ remUnit: remUnit}),      AutoPrefixer({ browsers: ["last 20 versions", "android >= 4.0"] })     ], "postcss-pxtorem": { rootValue: 23.4375, // 640 propList: ['*'], selectorBlackList: ['.tree-xxx'], minPixelValue: 1, exclude: /vue-search-tree/ig // src 目录下样式全部不转义 }   }; };