App.vue
main.js
 
<template>
  <h1>v-on Example</h1>
  <div v-bind:class="{ yelClass: bgColor }">
    <p>Click the button to change background color of this DIV box.</p>
    <button v-on:click="bgColor = !bgColor">Click</button>
    <p>bgColor property: "{{ bgColor }}"</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      bgColor: false
    };
  }
}
</script>

<style scoped>
.yelClass {
  background-color: rgb(255, 255, 136);
}
div {
  margin: 10px;
  padding: 10px;
  border: dashed black 1px;
  width: 250px;
}
</style>                  
import { createApp } from 'vue'

import App from './App.vue'

const app = createApp(App)
app.mount('#app')
                  
http://localhost:5173/