CSS
.page-header {
height: 100vh;
background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/9632/northernlights.jpg);
}
.page-header:after {
animation: grain 8s steps(10) infinite;
background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/9632/paper-pattern.png);
content: "";
height: 300%;
left: -50%;
opacity: 0.3;
position: fixed;
top: -110%;
width: 300%;
}
@keyframes grain {
0%, 100% { transform:translate(0, 0) }
10% { transform:translate(-5%, -10%) }
20% { transform:translate(-15%, 5%) }
30% { transform:translate(7%, -25%) }
40% { transform:translate(-5%, 25%) }
50% { transform:translate(-15%, 10%) }
60% { transform:translate(15%, 0%) }
70% { transform:translate(0%, 15%) }
80% { transform:translate(3%, 35%) }
90% { transform:translate(-10%, 10%) }
}