JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<body style="background-color:gray;">

<div class="container" style="width:100%; height:100%;">

    Some content
    <button>Some Button</button>
</div>


</div>

</body>
</html>

CSS

html, body {
    height: 100%;
    width: 100%;
    margin: 0;
    padding: 0;
}
body {
   display: table;
}
.container {
    display: table-row;
    height: 100%;
}