html {
  scroll-behavior: smooth;
}

a#backToTop{
    border-radius:50%;
    padding:10px;
    font-size:25px;
    text-align:center;
    color: var(--white-theme-color);
    background:rgba(0, 0, 0, 0.25);
    position:fixed;
    right:20px;
    opacity:1;
    z-index:99999;
    transition:all ease-in 0.5s;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    text-decoration: none;
    width: 6rem;
    height: 6rem;
  }

  a#backToTop:hover{
    background-color: var(--orange-theme-color);
    transition:all ease-in 0.2s;
  }

  a#backToTop.isNotVisible{
    bottom:-35px;
    opacity:0;
    transition:all ease-in 0.5s;
  }
  
  a#backToTop.isVisible{
    bottom:30px;
    opacity:1;
  }