body {
  font-family: sans-serif;
  background: #f8f8f8;
}
.quiz-container {
  max-width: 600px;
  margin: auto;
  background: white;
  padding: 20px;
  border-radius: 10px;
}
button {
  background: #0073bb;
  color: white;
  padding: 10px;
  border: none;
  cursor: pointer;
}
.hidden {
  display: none;
}