JSFiddle - React, Tailwind, and code Playground

HTML

<div id="app">
  <ul class="list">
    <li v-for="(b, index) in blocks">
      <div v-on:click="active = index === active ? null : index">{{ b.name }}</div>
      <div v-show="index === active" class="block">{{ index + 1 }} block</div>
    </li>
  </ul>
</div>

JavaScript

new Vue({
    el: '#app',
    data: {
      active: null,
      blocks: [
        { name: 'Один' },
        { name: 'Два' },
        { name: 'Три' }
      ]
    }
  })