vue-router路由问题：可以通过$router.push()跳转，但刷新后又变成空白页面

pageage.json

"vue": "~3.1.5",
"vue-axios": "~3.2.4",
"vue-router": "~4.0.10",

代码没有问题，一直搞不懂为什么通过this.$router.push(“/paper/detail”)可以跳进去，但是进去之后再刷新就一直是空白页面，各种百度/问AI，要么说 把mode的问题，换成hash/history；要么说服务端配置问题（静态前端跟服务端有毛的关系）；要么说需要路由嵌套（/paper的children里面写/detail，这2是同级的，又不是父嵌子）

最后终于意识到是publicPath: '/'的问题：
例如，在 vue.config.js 中：

module.exports = {
  publicPath: '/' // 默认是'./'
}

或者在 webpack.config.js 中配置静态资源目录：

output: {
  publicPath: '/static/',  // 根据需要修改路径
}

router.js

import { createRouter, createWebHistory } from 'vue-router';
import EleLayout from '@/layout/index';
// 静态路由
const routes = [
  {
    path: '/:pathMatch(.*)*',
    component: () => import('@/views/exception/404')
  },
];
const mainRouter = [
  {
    path: "/index",
    component: () => import('@/views/index/index'),
    meta: { title: "主页", keepAlive: true }
  },
  {
    path: "/paper",
    component: () => import('@/views/paper/index'),
    meta: { title: "公文", keepAlive: true },
  },
  {
    path: "/paper/detail",
    component: () => import('@/views/paper/detail'),
    meta: { title: "公文", keepAlive: true }
  },
]

const router = createRouter({
  mode: 'history', // hash history
  routes,
  history: createWebHistory(),
  scrollBehavior: (to, from, savedPosition) => {
    if (savedPosition) {
      return savedPosition;
    } else {
      return { top: 0, left: 0 };
    }
  }
});

router.beforeEach((to, from, next) => {
    // 将新的子路由添加到父路由中
    router.addRoute({
      path: '/',
      redirect: '/index',
      name: 'layout',
      component: EleLayout,
      children: mainRouter
    });    
    next({ ...to, replace: true });
});

export default router;