JSFiddle - React, Tailwind, and code Playground

HTML

<div> Some Content</div>

CSS

body
{
    background-image: url(http://placehold.it/200x200/ff0000/ffffff&text=BG+Image);
}


body:before
{
    display:block;
    opacity:0.5;
    background-color:darkgrey;
    position:absolute;
    top:0;
    bottom:0;
    left:0;
    right:0;
    content:"";
    z-index:-1;
    
    
}