.button {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

#buy {
  padding: 1.2rem 6rem;
  border: 0.065rem solid #000;
  border-radius: 6px;
  color: #fff;
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.111rem;
  transition: all 0.15s ease-in-out;
  background-color: #000;
}

#buy:hover {
  cursor: pointer;
  background-color: #ff91e7;
  color: #000;
  scale: 0.9;
}

#btn_back {
  width: 100%;
  height: 100%;
  background-color: #000;
  position: absolute;
  bottom: 0;
  right: 0;
  border-radius: 6px;
  z-index: -1;
}