#qr-reader {
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
}

#result {
    text-align: center;
    font-size: 1.5em;
    margin-top: 20px;
    padding: 10px;
}

.install-btn {
  display: none;
  margin: 20px auto;
  padding: 10px 20px;
  background: #4a90e2;
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}

.install-btn:hover {
  background: #3a7bc8;
}