#back-to-top {
  position: fixed;
  bottom: 40px;
  right: 40px;
  z-index: 9999;
  width: 64px;
  height: 64px;
  text-align: center;
  line-height: 60px;
  background: @text_color;//rgba(0,0,0,0.5);
  //    webkit-box-shadow: 0px 0px 10px 0px rgba(0, 0, 0, .8);
   -webkit-transition: all 0.5s ease-out;
  //    box-shadow: 0px 0px 10px 0px rgba(0, 0, 0, .8);
  color: #fff;
  cursor: pointer;
  border: 0;
  border-radius: 50%;
  text-decoration: none;
  transition: all 1s ease;
  opacity: 1;

  -webkit-box-shadow: 0px 0px 10px 0px rgba(0, 0, 0, .8);
  box-shadow: 0px 0px 10px 0px rgba(0, 0, 0, .8);
  img {
    //    transform: rotate(90deg);
    width: 50px;
    padding: 8px;
  }
}
#back-to-top:hover {
  background: @major_color;

}
#back-to-top.show {
  opacity: 0;
   bottom: -999px;
    transition: all 1s ease;
}