• css中使用>>>
• scss中使用::v-deep

1. css

<template>
  <div class="a" v-html="content"></div>
</template>

<script>
import { ref } from 'vue'

export default { 
  setup() {
    let content = ref( 'this is a <a class="b">Test</a>')
  }
  return {
      content
    }
  }
}
</script>

<style scoped>
  .a >>> .b {
    color: red;
  }
</style>

2. scss

<template>
  <div class="a" v-html="content"></div>
</template>

<script>
import { ref } from 'vue'

export default { 
  setup() {
    let content = ref( 'this is a <a class="b">Test</a>')
  }
  return {
      content
    }
  }
}
</script>

<style lang="scss" scoped>
  .a ::v-deep .b {
    color: red;
  }
</style>