.position-container {
position: relative;
}
.position-container:after {
content : "";
display: block;
position: absolute;
top: 0;
left: 0;
background-image: url(https://hsto.org/webt/5b/ac/ff/5bacff616663f822951184.jpeg);
width: 100%;
height: 100%;
opacity : 1;
z-index: -1;
}