.hovertext {
    position: relative;
    border-bottom: 1px dotted black;
  }
  
  .hovertext:before {
    content: attr(data-hover);
    visibility: hidden;
    opacity: 0;
    width: 250px;
    background-color: black;
    color: #fff;
    text-align: center;
    border-radius: 5px;
    padding: 5px 0;
    transition: opacity 1s ease-in-out;
  
    position: absolute;
    z-index: 1;
    left: 0;
    top: 110%;
  }
  
  .hovertext:hover:before {
    opacity: 1;
    visibility: visible;
  }