.popupWindow {              /*  changed to class(.)  vs id(#)    */
     position: fixed;
     top: 50%;
     left: 50%;
     transform: translate(-50%, -50%);
     background-color: white;
     padding: 20px;
     border-radius: 5px;
     box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
     display: none; /* Hidden by default */
     z-index: 1000; /* Ensure it's on top of the overlay */
   }