tailwind.config.js#
export default {
  darkMode: "class",
  ...
};
App.vue#
<template>
  <div :class="{ dark: isdark }">
    <div
      class="w-screen h-screen bg-white dark:bg-gray-800 transform transition-all duration-300"
    >
      <button @click="isdark = true">深色模式</button>
      <button @click="isdark = false">浅色模式</button>
    </div>
  </div>
</template>
<script setup lang="ts">
import { ref } from "vue";
const isdark = ref(false);
</script>