.back-to-top {
    position: fixed;
    visibility: hidden;
    opacity: 0;
    right: 30px;
    bottom: 50px;
    z-index: 996;
    width: 65px;
    height: 65px;
    border-radius: 4px;
    transition: all 0.4s;
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.7);
    border-radius: 50%;
  }
  
  .back-to-top i {
    font-size: 28px;
    color: #fff;
    line-height: 0;
  }
  
  
  .back-to-top.active {
    visibility: visible;
    opacity: 1;
  }