JSFiddle - React, Tailwind, and code Playground

HTML

<div class="content">

</div>

CSS

.content {
  overflow: auto;
  position: relative;
}
.content:before {
  content: "";
  position: fixed;
  left: -1%;
  right: -1%;
  top: -1%;
  bottom: -1%;
  z-index: -1;
  
  display: block;
  background-image: url(http://hdwallpaperfun.com/wp-content/uploads/2014/08/Snow-Mountain-Wallpaper-High-Definition.jpg);
  background-size: cover;
  width: 102%;
  height: 102%;
  
  -webkit-filter: blur(5px);
  -moz-filter: blur(5px);
  -o-filter: blur(5px);
  -ms-filter: blur(5px);
  filter: blur(5px);
}