<template>
  <div class="menu-item" @click="isOpen = !isOpen">
    <a href="#">
      {{ title }}
    </a>
    <svg viewBox="0 0 1030 638" width="10">
      <path d="M1017 68L541 626q-11 12-26 12t-26-12L13 68Q-3 49 6 24.5T39 0h952q24 0 33 24.5t-7 43.5z" fill="#FFF"></path>
    </svg>
    <transition name="fade" appear>
      <div class="sub-menu" v-if="isOpen">
        <div v-for="(item, i) in items" :key="i" class="menu-item">
          <a :href="item.link">{{ item.title }}</a>
        </div>
      </div>
    </transition>
  </div>
</template>

<script>
export default {
  name: 'dropdown',
  props: ['title', 'items'],
  data () {
    return {
      isOpen: false
    }
  }
}
</script>

<style>
nav .menu-item svg {
  width: 10px;
  margin-left: 10px;
}

nav .menu-item .sub-menu {
  position: absolute;
  background-color: #222;
  top: calc(100% + 18px);
  left: 50%;
  transform: translateX(-50%);
  width: max-content;
  border-radius: 0px 0px 16px 16px;
}

.fade-enter-active,
.fade-leave-active {
  transition: all .5s ease-out;
}

.fade-enter,
.fade-leave-to {
  opacity: 0;
}
</style>

<template>
  <nav>
    <div class="menu-item"><a href="#">点赞</a></div>
    <div class="menu-item"><a href="#">投币</a></div>
    <Dropdown title="关注" :items="关注" />
    <div class="menu-item"><a href="#">收藏</a></div>
  </nav>
</template>

<script>
import Dropdown from './Dropdown';

export default {
  name: '关注',
  components: {
    Dropdown
  },
  data () {
    return {
      '关注': [
        {
          title: '少轻狂',
          link: 'https://space.bilibili.com/237173875/'
        },
        {
          title: '敏捷开发',
          link:'https://space.bilibili.com/237173875/'
        },
        {
          title: '导航栏',
          link: 'https://space.bilibili.com/237173875/'
        }
      ]
    }
  }
}
</script>

<style>
nav {
  display: flex;
  align-items: center;
  justify-content: center;
}

nav .menu-item {
  color: #FFF;
  padding: 10px 20px;
  position: relative;
  text-align: center;
  border-bottom: 3px solid transparent;
  display: flex;
  transition: 0.4s;
}

nav .menu-item.active,
nav .menu-item:hover {
  background-color: #444;
  border-bottom-color: #FF5858;
}

nav .menu-item a {
  color: inherit;
  text-decoration: none;
}
</style>