JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <section id="container">
    <link />
    <section id="box">
        <h1>
           Hello there. 
        </h1>
        <p>What is up, friend?</p>
        
    </section><div class="clear"></div>
    </section>
</body>

CSS

html, body {
    margin: 0;
    padding: 0;
}

#container {padding: 10px; background: grey}

#container * {margin: 10px; background: lightgrey;}

#box {margin: 0; background: green;}

.clear {
  clear: both;
  display: block;
  overflow: hidden;
  visibility: hidden;
  width: 0;
  height: 0;
}