#back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: #f5f5f5;
    color: #73a1c9;
    padding: 10px;
    border-radius: 5px;
    cursor: pointer;
    z-index: 1000;
  }
  #back-to-top:hover {
    background-color: #e9e9e9;
  }