.qr-button {
  font-family: arial;
  font-weight: bold;
  display: inline-block;
  text-decoration: none;
  background-color: #339933;
  color: #fff;
  padding: 10px 25px;
  border-radius: 5px;
  margin: 5px;
}

.qr-button:hover {
  color: #000;
  background-color: #aaffaa;
}