body:before{
content: 'Please turn on Javascript';

color: white;
font-family: sans-serif;
font-size: 1em;
font-weight: bold;
text-align: center;

width: 100%;
height: 100%;
padding: 25% 0;

background: rgba(0,0,0,0.9);
position: fixed;
top: 0;
left: 0;
z-index: 99999;
}