JSFiddle - React, Tailwind, and code Playground

HTML

<header>
    header
    </header>

    <div id="main">
    main
    </div>

    <footer>
    footer
    </footer>

CSS

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

        header {
            position:fixed;
            top:0;
            width:100%;
            height:40px;
            background-color:#333;
            padding:20px;
        }

        footer {
            background-color: #333;
            width: 100%;
            bottom: 0;
            position: fixed;
        }
        #main{
            padding-top:100px;
            text-align:center;
        }