.centered {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}
@keyframes terrain {
    from{ opacity: 0; }
    to {opacity:1; }

}
.container {
    z-index:10;
    border-style: solid;
    border-color: black;
    background-color: black;
    width: 906px;
    border-radius: 10px;
    animation-name: terrain;
    animation-duration: 0.4s;
}
.terrain {
    z-index: 9;
    backgound-color:black;
    opacity:0.7
}
.fullscreen {
    position: fixed;
    top: 0;
    left: 0;
    bottom:0;
    right:0;
   
}