body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 20px;
  background: #f0f2f5;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}
#quiz-container {
  max-width: 600px;
  width: 100%;
  background: white;
  padding: 40px;
  border-radius: 16px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
h1 {
  color: #1a1a1a;
  margin-top: 0;
}
button {
  background: #1877f2;
  color: white;
  border: none;
  padding: 12px 24px;
  border-radius: 6px;
  font-size: 16px;
  font-weight: bold;
  cursor: pointer;
  margin-top: 16px;
  width: 100%;
}
button:hover {
  background: #166fe5;
}
label {
  display: block;
  margin: 8px 0;
  cursor: pointer;
}
#resultado {
  margin-top: 20px;
  padding: 16px;
  background: #e7f3ff;
  border-radius: 8px;
  color: #0c3d6b;
}