Vue3 navigation bar component encapsulation implementation method

<template>
  <header class="app-header">
    <div class="container">
      <!-- Header navigation area -->
      <HeaderNavCommon />
      <div class="search">
        <i class="iconfont icon-search"></i>
        <input type="text" placeholder="Search" />
      </div>
      <div class="cart">
        <a href="#" class="curr">
          <i class="iconfont icon-cart"></i>
          <em>2</em>
        </a>
      </div>
    </div>
  </header>
</template>
 
<script>
import HeaderNavCommon from '@/components/header-nav-common.vue'
export default {
  name: 'AppHeader',
  components:
    HeaderNavCommon
  }
}
</script>
 
<style scoped lang="less">
.app-header {
  background: #fff;
  .container {
    display: flex;
    align-items: center;
  }
  .navs {
    width: 820px;
    display: flex;
    justify-content: space-around;
    padding-left: 40px;
    li {
      margin-right: 40px;
      width: 38px;
      text-align: center;
      a {
        display: inline-block;
        font-size: 16px;
        line-height: 32px;
        height: 32px;
      }
      &:hover {
        a {
          color: @xtxColor;
          border-bottom: 1px solid @xtxColor;
        }
      }
    }
  }
  .search {
    width: 170px;
    height: 32px;
    position: relative;
    border-bottom: 1px solid #e7e7e7;
    line-height: 32px;
    .icon-search {
      font-size: 18px;
      margin-left: 5px;
    }
    input {
      width: 140px;
      padding-left: 5px;
      color: #666;
    }
  }
  .cart {
    width: 50px;
    .curr {
      height: 32px;
      line-height: 32px;
      text-align: center;
      position: relative;
      display: block;
      .icon-cart {
        font-size: 22px;
      }
      em {
        font-style: normal;
        position: absolute;
        right: 0;
        top: 0;
        padding: 1px 6px;
        line-height: 1;
        background: @helpColor;
        color: #fff;
        font-size: 12px;
        border-radius: 10px;
        font-family: Arial;
      }
    }
  }
}
</style>

<template>
  <ul class="app-header-nav">
    <li class="home"><RouterLink to="/">Home</RouterLink></li>
    <li><a href="#" >Delicious food</a></li>
    <li><a href="#" >Kitchen</a></li>
    <li><a href="#" >Art</a></li>
    <li><a href="#" >Electrical appliances</a></li>
    <li><a href="#" >Home</a></li>
    <li><a href="#" >Care</a></li>
    <li><a href="#" >Pregnancy and Infant</a></li>
    <li><a href="#" >Clothing</a></li>
    <li><a href="#" >Groceries</a></li>
  </ul>
</template>
 
<script>
 export default {
    name: 'AppHeaderNav'
   }
</script>
 
<style scoped lang='less'>
.app-header-nav {
    width: 820px;
    display: flex;
    padding-left: 40px;
    position: relative;
    z-index: 998;
  li {
    margin-right: 40px;
    width: 38px;
    text-align: center;
  a {
    font-size: 16px;
    line-height: 32px;
    height: 32px;
    display: inline-block;
   }
  &:hover {
    a {
    color: @xtxColor;
    border-bottom: 1px solid @xtxColor;
        }
      }
  }
}
</style>

<template>
  <div class="app-header-sticky" :class="{ show: top >= 78 }">
    <div class="container" v-if="top >= 78">
      <!-- Middle -->
      <HeaderNavCommon />
      <!-- Right button -->
      <div class="right">
        <RouterLink to="/">Brand</RouterLink>
        <RouterLink to="/">Topic</RouterLink>
      </div>
    </div>
  </div>
</template>
 
<script>
import HeaderNavCommon from '@/components/header-nav-common.vue'
// import { ref } from 'vue'
import { useWindowScroll } from '@vueuse/core'
export default {
  name: 'AppHeaderSticky',
  components: { HeaderNavCommon },
  setup() {
    // Page scroll distance // const top = ref(0)
    // window.onscroll = () => {
    // top.value = document.documentElement.scrollTop
    // }
    // Page scrolling using third-party packages const { y: top } = useWindowScroll()
    return { top }
  }
}
</script>
 
<style scoped lang="less">
.app-header-sticky {
  width: 100%;
  height: 80px;
  position: fixed;
  left: 0;
  top: 0;
  z-index: 999;
  background-color: #fff;
  border-bottom: 1px solid #e4e4e4;
  // This is the key style!!!
  // By default, move yourself completely to the top transform: translateY(-100%);
  // Completely transparent opacity: 0;
  //Displayed class name&.show {
    transition: all 0.3s linear;
    transform: none;
    opacity: 1;
  }
  .container {
    display: flex;
    align-items: center;
  }
  .right {
    width: 220px;
    display: flex;
    text-align: center;
    padding-left: 40px;
    border-left: 2px solid @xtxColor;
    a {
      width: 38px;
      margin-right: 40px;
      font-size: 16px;
      line-height: 1;
      &:hover {
        color: @xtxColor;
      }
    }
  }
}
</style>