按照老师的教程，我把viewport.js引入到项目里了，但是px没有转换成rem ，代码如下
vue.config.js

const path = require('path')

function resolve (dir) {
  return path.join(__dirname, dir)
}

module.exports = {
  configureWebpack: config => {
    config.entry.app = ['./src/viewport.js', './src/main.js']
  },
  chainWebpack: (config) => {
    config.module.rule('css')
      .test(/\.css$/)
      .oneOf('vue')
      .resourceQuery(/\?vue/)
      .use('px2rem')
      .loader('px2rem-loader')
      .options({
        remUnit: 75,
        remPrecision: 8
      })

    config.module.rule('vue').use('vue-loader').loader('vue-loader')
    config.resolve.alias.set('@', resolve('src'))
      .set('api', resolve('src/server/api'))
      .set('utils', resolve('src/utils'))
      .set('assets', resolve('src/assets'))
      .set('components', resolve('src/components'))
      .set('views', resolve('src/views'))
      .set('layout', resolve('src/views/layout/components'))
      .set('styles', resolve('src/styles'))
  },
  devServer: {
    port: 8085, // 端口号
    // host: '192.168.0.103',
    host: 'localhost',
    https: false, // https:{type:Boolean}
    open: true, // 配置自动启动浏览器
    proxy: {
      '/api': {
        target: 'http://10.12.252.214:8080/',
        ws: true,
        changeOrigin: true
      }
    }
  }
}

标签已经有变化了，但是px没有转成rem,可以帮我看下吗？谢谢啦