JSFiddle - React, Tailwind, and code Playground

HTML

<div class = "tint">
    <span class = "whitecontent">Hey -- I'm some content!</span>
</div>

CSS

html {
 background-image: url(http://www.impawards.com/tv/posters/glee_ver9_xlg.jpg   );
    background-attachment: fixed;
    background-size: 100%;
}
html, body {
 min-height: 100%;
 min-wwidth: 100%;    
}
.tint {
    z-index: 1;
 height: 100%;
width: 100%;
position: absolute;
top: 0px;
left: 0px;
background: rgba(0, 0, 0, 0.7);    
}
.whitecontent {
 color: white;
}