JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
<img src="http://via.placeholder.com/450x700"/>
  <div class="fixed">
  </div>
</body>
</html>

CSS

body{
  margin:0;
}
.fixed{
  position:fixed;
  bottom:0;
  background:#f00;
  width:100%;
  height:30px;
}