button.back-to-top {
  margin: 0 !important;
  padding: 0 !important;
  background: #fff;
  height: 0px;
  width: 0px;
  overflow: hidden;
  border-radius: 50px;
  -webkit-border-radius: 50px;
  -moz-border-radius: 50px;
  color: transparent;
  clear: both;
  visibility: hidden;
  position: fixed;
  cursor: pointer;
  display: block;
  border: none;
  right: 50px;
  bottom: 75px;
  font-size: 0px;
  outline: 0 !important;
  z-index: 99;
  -webkit-transition: all .3s ease-in-out;
  transition: all .3s ease-in-out;
}
button.back-to-top i{
  color: #FF001A;
  font-size: 15px;
}

button.back-to-top:hover,
button.back-to-top:active,
button.back-to-top:focus {
  outline: 0 !important;
}



button.back-to-top.show {
  display: block;
  background: #fff;
  right: 25px;
  bottom: 50px;
  height: 40px;
  width: 40px;
  visibility: visible;
  box-shadow: 0px 2px 4px 1px rgba(0, 0, 0, 0.55);
  -webkit-box-shadow: 0px 2px 4px 1px rgba(0, 0, 0, 0.55);
  -moz-box-shadow: 0px 2px 4px 1px rgba(0, 0, 0, 0.55);
}

button.back-to-top.show:active {
  box-shadow: 0px 4px 8px 2px rgba(0, 0, 0, 0.25);
  -webkit-box-shadow: 0px 4px 8px 2px rgba(0, 0, 0, 0.25);
  -moz-box-shadow: 0px 4px 8px 2px rgba(0, 0, 0, 0.25);
}