body {
  transition: background-color 0.3s ease, color 0.3s ease;
  font-family: Arial, sans-serif;
  padding: 2rem;
  text-align: center;
}

body.light {
  background-color: #ffffff;
  color: #121212;
}

body.dark {
  background-color: #121212;
  color: #ffffff;
}

#toggle-btn {
  padding: 10px 20px;
  cursor: pointer;
  margin-top: 20px;
  border: none;
  border-radius: 5px;
  background-color: #555;
  color: #fff;
}