.footnote .footnotetext {
  visibility: hidden;
  width: 500px;
  background-color: #E1E1E1;
  color: black;
  text-align: center;
  padding: 20px 20px;
  border-radius: 6px;
  position: absolute;
  z-index: 1;
  top: -5px;
  right: 20px;
  opacity: 0;
  transition: opacity 1s;
  ;
    }
    
    .footnote:hover .footnotetext {
      visibility: visible;
      opacity: 1;
    }