#backToTopBtn {
  position: fixed;
  bottom: 40px;
  right: 25px;
  z-index: 999;
  border: none;
  outline: none;
  background-color: #15803d;
  color: white;
  cursor: pointer;
  padding: 12px 15px;
  border-radius: 50%;
  font-size: 18px;
  display: none;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

#backToTopBtn:hover {
  background-color: #166534;
}