Add Remove Class to Body - Toggle Class

<!DOCTYPE html>
<html>
  <head>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
  </head>

<body :class="{ active: isBodyClassActive }">
    <div id="app">
      <h3>Vue js Add Remove class to Body Tag | Toggle class</h3>
      <button @click="toggleBodyClass">Toggle Body Class</button>
    </div>

<script  type="module">
      const app = new Vue({
        el: "#app",
        data() {
          return {
            isBodyClassActive: false,
          };
        },
        methods: {
          toggleBodyClass() {
            this.isBodyClassActive = !this.isBodyClassActive;
          },
        },
        watch: {
          isBodyClassActive(newVal) {
            if (newVal) {
              document.body.classList.add("active");
            } else {
              document.body.classList.remove("active");
            }
          },
        },
      });
    </script>
    <style>
      body.active {
        background-color: lightgreen;
      }
      button {
        padding: 10px 20px;
        font-size: 18px;
        background-color: #4caf50;
        color: white;
        border: none;
        cursor: pointer;
      }
    </style>
  </body>
</html>