body {
  font-family: Arial, sans-serif;
  max-width: 600px;
  margin: auto;
  padding: 20px;
  background: #f9f9f9;
}
h1 {
  text-align: center;
  color: #333;
}
button {
  margin: 8px;
  padding: 8px 12px;
}
.correct {
  background-color: #aaf0aa;
}
.wrong {
  background-color: #f0aaaa;
}
#feedback {
  margin-top: 10px;
  font-weight: bold;
}