<div id="app">
  <h1 class="bigFontSize" :class="{ bgColor: isChange}">標題一</h1>
  <button class="btn btn-primary" @click="isChange = !isChange">轉換樣式</button>
</div>
.bigFontSize {
  font-size: 30px;
}
.bgColor {
  background-color: red;
}
.FontColor {
  color: #fff;
}
.btn {
  padding: 10px 20px;
  border-radius: 5px;
  border:1px solid transparent;
  font-size: 2rem;
}
.btn:hover {
  cursor: pointer;
}
.btn-primary {
  background-color: #0d6efd;
  border:1px solid #0d6efd;
  color: #fff;
}
;(function(){
  let vm = new Vue({
    el: '#app',
    data: {
      link: {
        href: 'https://www.google.com/',
        target: '_black',
        content: 'Google'
      },
      isChange: true
    }
  })
})()

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/vue/2.6.11/vue.min.js