<div id="app">
  <p class="alert alert-info">{{ message }}</p>
  <input type="text" v-model="message">
</div>

html, body {
  display: grid;
  justify-content: center;
  align-content: center;
  
  height: 100%;
  width: 100%;
}

const app = Vue.createApp({
  data: function () {
    return { message: 'Hello' }
  }
})

const vm = app.mount('#app')