body {
  font-family: Arial, sans-serif;
  background-color: #f4f4f4;
  color: #333;
  display: flex;
  justify-content: center;
  padding: 2rem;
  transition: background 0.3s, color 0.3s;
}

body.dark {
  background-color: #111;
  color: #eee;
}

.container {
  max-width: 400px;
  width: 100%;
  text-align: center;
}

input {
  width: 100%;
  padding: 0.7rem;
  font-size: 1rem;
  margin-bottom: 1rem;
}

button {
  padding: 0.7rem 1.2rem;
  background: #007bff;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  margin-top: 1rem;
}

button:hover {
  background: #0056b3;
}

#qrBox {
  margin-top: 1.5rem;
}

#downloadLink {
  display: block;
  margin-top: 1rem;
  color: #007bff;
  text-decoration: none;
}

.toggle {
  margin-top: 2rem;
  background: #444;
}