vue路由中设置linkActiveClass

export default new Router({
  linkActiveClass: 'active',//设置 链接激活时使用的 CSS 类名。默认值可以通过路由的构造选项 linkActiveClass 来全局配置
  routes: [
   
  ]
})

.nav .active {
  color: #ffbb22;
}

<div class="nav">
   <router-view></router-view>
   <router-link class="nav-item" to="/nav1">nav1</router-link>
   <router-link class="nav-item" to="/nav2">nav2</router-link>
   <router-link class="nav-item" to="/nav3">nav3</router-link>
</div>