Native JS encapsulation vue Tab switching effect

<template>
  <div class="bookcircle-header">
    <ul class="wrapper" :class="headerActive == 0 ? 'friend' : 'booklist'">
      <li @click="headerChange(0)" :class="headerActive == 0 ? 'active' : ''">
        Book Friends</li>
      <li @click="headerChange(1)" :class="headerActive == 1 ? 'active' : ''">
        Book list</li>
    </ul>
  </div>
</template>

<script>
export default {
  components: {},
  data() {
    return {
      headerActive: 0,
    };
  },
  computed: {},
  created() {},
  mounted() {
    //Initialize the send this.$emit("change", this.headerActive);
  },
  methods: {
    headerChange(index) {
      this.headerActive = index;
      this.$emit("change", index);
    },
  },
};
</script>

<style lang="less" scoped>
.bookcircle-header {
  height: 42px;
  display: flex;
  justify-content: center;
  align-items: center;
  .wrapper {
    width: 286px;
    font-size: 14px;
    height: 29px;
    color: #1489fe;
    border: 1px solid #1489fe;
    border-radius: 14px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    box-sizing: border-box; // Solve border overflow and include border inside the box li {
      flex: 1;
      height: 100%;
      display: flex;
      justify-content: center;
      align-items: center;
      z-index: 2;
    }
    .active {
      color: white;
    }
    &::before {
      content: "";
      width: 143px;
      height: 100%;
      background-color: #1489fe;
      position: absolute;
      top: 0px;
      left: 0px;
      border-radius: 13px 0px 0px 13px;
      z-index: 1;
      transition: all 0.3s;
    }
    &.firend::before {
      transform: translateX(0);
      border-radius: 13px 0px 0px 13px;
    }
    &.booklist::before {
      transform: translateX(100%);
      border-radius: 0px 13px 13px 0px;
    }
  }
}
</style>