yj_vue3/src/App.vue

<template>
	<div id="app">
	  <router-view/>
	</div>
  </template>
  
  <style>
  #app {
	font-family: Avenir, Helvetica, Arial, sans-serif;
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
	text-align: center;
	color: #2c3e50;
  }
  
  nav {
	padding: 30px;
  
	a {
	  font-weight: bold;
	  color: #2c3e50;
  
	  &.router-link-exact-active {
		color: #42b983;
	  }
	}
  }
  </style>