#scroll-to-top {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: orange;
    color: white;
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    z-index: 99;
    opacity: 0.7;
    transition: opacity 0.3s;
  }
  
  #scroll-to-top:hover {
    opacity: 1;
  }
  
  #scroll-to-top i {
    font-size: 20px;
  }