.popup {
   opacity: 0;
   position: fixed;

   left: 50%;
   transform: translate(-50%, 0);

   z-index: 1;
   top: 40px;
   font-weight: 400;
   font-size: 14px;
   color: white;
   background-color: black;
   padding: 10px;
   border-radius: 5px;

   transition-property: opacity;
   transition-duration: 500ms;
   transition-timing-function: ease-in-out;
}

.popup.show {
   opacity: 1;

}