* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 30px 15px;
  font-family: Arial, sans-serif;
  background-color: #f1f5f9;
  color: #1e293b;
}

.container {
  max-width: 850px;
  margin: auto;
  padding: 30px;
  background-color: white;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.12);
}

h1 {
  margin-top: 0;
  color: #2563eb;
  text-align: center;
}

.intro {
  text-align: center;
  margin-bottom: 30px;
}

.question {
  margin: 25px 0;
  padding: 20px;
  background-color: #f8fafc;
  border-left: 5px solid #2563eb;
  border-radius: 6px;
}

.question h2 {
  margin-top: 0;
  font-size: 18px;
}

label {
  display: block;
  margin: 8px 0;
  padding: 10px;
  border-radius: 6px;
  cursor: pointer;
}

label:hover {
  background-color: #e2e8f0;
}

input {
  margin-right: 8px;
}

button {
  width: 100%;
  padding: 14px;
  border: none;
  border-radius: 8px;
  background-color: #2563eb;
  color: white;
  font-size: 17px;
  cursor: pointer;
}

button:hover {
  background-color: #1d4ed8;
}

.correct {
  background-color: #dcfce7;
  color: #166534;
  font-weight: bold;
}

.wrong {
  background-color: #fee2e2;
  color: #991b1b;
  font-weight: bold;
}

.feedback-correct {
  margin: 12px 0 0;
  padding: 10px;
  border-radius: 6px;
  background-color: #bbf7d0;
  color: #166534;
  font-weight: bold;
}

#result {
  display: none;
  margin-top: 25px;
  padding: 18px;
  border-radius: 8px;
  background-color: #dbeafe;
  color: #1e40af;
  text-align: center;
  font-size: 18px;
  font-weight: bold;
}