#myBtn {
  opacity: 0;
  position: fixed;
  bottom: 20px;
  /* right: 30px; */
  left: 20px;
  z-index: 99;
  font-size: 18px;
  border: none;
  outline: none;
  /* background: linear-gradient(to bottom, #D78440, #FF179A); */
  color: white;
  cursor: pointer;
  padding: 10px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  transition: 0.5s
}

#myBtn:hover {
  box-shadow: rgba(100, 100, 111, 0.2) 0px 7px 29px 0px;
}