JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Test of coderwall background effect</title>
    <meta charset="utf-8">
</head>
<body class="body-bg">
    <canvas class="blur" src="https://d3levm2kxut31z.cloudfront.net/assets/locations/Mexico-1c39f581666a50a97c5130e13837ff20.jpg" width="300" height="200"></canvas>    
</body>
</html>

CSS

.body-bg {
  background: #393939;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

.blur {
  min-width: 100%;
  min-height: 100%;
  position: fixed;
  top: 0;
  left: 0;
  z-index: -2;
  opacity: 0.7;
}