JSFiddle - React, Tailwind, and code Playground

HTML

<h1 class="box">Hello World</h1>
<div class="box" id="first"></div>
<div class="box" id="second"></div>

CSS

.box { height: 50px; background: #0F0; width: 100%; margin-top: 10px; }
#first { margin-top: 20px; }
#second { background: #00F; }
h1.box { background: #F00; margin-bottom: 50px;  }