Header.js File

<template>
  <div id="nav">
    <ul>
      <router-link to="/" tag="li" active-class="active" exact> <a>Home</a> </router-link>
      <router-link to="/user" tag="li" active-class="active"> <a>User1</a> </router-link>

      <router-link to="/user">User</router-link>
    </ul>

  </div>
</template>

<script>
export default {

}
</script>

<style>
#nav {
  font-family: 'Avenir', Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}

ul {
  list-style-type: none;
  padding: 0;
}

li {
  display: inline-block;
  margin: 0 10px;
  padding: 10px;
}

a {
  color: #b96442;
}
.active{
  background-color:#42b983;
}
</style>

VueJs Routing