body {
  font-family: Arial, sans-serif;
  background-color: #f8f9fa;
  color: #333;
  margin: 0;
  padding: 2rem;
  transition: background-color 0.3s ease, color 0.3s ease;
}
.container {
  max-width: 600px;
  margin: auto;
  text-align: center;
}
.dark-mode {
  background-color: #121212;
  color: #f0f0f0;
}
button {
  margin-top: 20px;
  padding: 10px 15px;
  font-size: 16px;
  cursor: pointer;
}