.viewer-full {
    position: fixed;
    top: 0px;
    width: 90%;
    margin-left: auto;
    margin-right: auto;
    display: block;
    text-align: center;
    left: 5%;
    right: 5%;
    display: none;
}

.closebtn-full {
    position: fixed;
    right: 7%;
    top: 3%;
}

.img-box {
    height: 98vh;
    overflow-y: scroll;
    margin-top: 1%;
}
.img-box ::-webkit-scrollbar {
    width: 5px;
  }
  
  .img-box ::-webkit-scrollbar-track {
    background: #f1f1f1;
  }
  
  .img-box ::-webkit-scrollbar-thumb {
    background: #888;
  }
  
  .img-box ::-webkit-scrollbar-thumb:hover {
    background: #555;
  }

@media only screen and (max-width:768px) {
    .viewer-full {
        position: fixed;
        top: 0px;
        width: 96%;
        margin-left: auto;
        margin-right: auto;
        display: block;
        text-align: center;
        left: 2%;
        right: 2%;
        display: none;
    }

    .closebtn-full {
        position: fixed;
        right: 3%;
        top: 3%;
    }
}