.popup-message {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  background-color: #333;
  color: #fff;
  text-align: center;
  font-size: 16px;
  padding: 10px;
}

@media only screen and (max-width: 767px) {
  .popup-message {
    display: block;
  }
}