html {
  scroll-behavior: smooth;
}
#myBtn {
  display: none;
  position: fixed;
  bottom: 20%;
  right: 30px;
  z-index: 99;
  font-size: 18px;
  border: none;
  outline: none;
  background-color: #a51f04;
  color: white;
  cursor: pointer;
  padding: 15px;
  border-radius: 4px;
  opacity: 0.4;
}