* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: #f5f5f5;
  font-family: Arial, sans-serif;
  color: #222;
}

.container {
  max-width: 700px;
  margin: auto;
  padding: 16px;
}

h1 {
  text-align: center;
  margin-bottom: 24px;
}

.section-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.section-btn {
  padding: 16px;
  border: none;
  border-radius: 12px;
  background: white;
  cursor: pointer;
  font-size: 16px;
}

.mode-buttons {
  margin-top: 20px;
}

.mode-buttons button {
  width: 100%;
  padding: 16px;
  border: none;
  border-radius: 12px;
  background: #111;
  color: white;
  cursor: pointer;
}

.hidden {
  display: none;
}

.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.card {
  background: white;
  border-radius: 16px;
  padding: 20px;
}

.chapter {
  font-size: 14px;
  color: #666;
}

.question-number {
  margin-top: 10px;
  color: #999;
}

.question {
  margin-top: 20px;
  font-size: 20px;
  line-height: 1.6;
}

.translate-btn {
  margin-top: 16px;
  padding: 10px 14px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

.translation {
  margin-top: 12px;
  background: #f3f3f3;
  padding: 14px;
  border-radius: 10px;
  line-height: 1.6;
}

.options {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.option-btn {
  padding: 14px;
  border: 1px solid #ddd;
  border-radius: 10px;
  background: white;
  cursor: pointer;
  text-align: left;
}

.option-btn.correct {
  background: #d7ffd7;
}

.option-btn.wrong {
  background: #ffd7d7;
}

.answer-area {
  margin-top: 20px;
}

#result {
  font-size: 20px;
  font-weight: bold;
}

#correctAnswer {
  margin-top: 10px;
  color: #666;
}

.answer-area button {
  margin-top: 20px;
  padding: 12px 16px;
  border: none;
  border-radius: 10px;
  background: #111;
  color: white;
  cursor: pointer;
}

@media (max-width: 600px) {
  .question {
    font-size: 18px;
  }
}