header::before {
    content: "";
     position: absolute;
     top: 0;
     left: 0;
     width: 100%;
     height: 100%;
     background-image: url('../images/1.jpg'); 
     background-position: bottom;
     background-size: cover;
     opacity: 0.8; 
     z-index: -1;
     box-shadow: inset 0px 700px 300px -600px #121212;
 
 }