body {
  font-family: 'Hiragino Maru Gothic ProN', 'Rounded M+ 1c', 'Meiryo', sans-serif;
  background-color: #f7f9f9;
  color: #333;
  margin: 0;
  padding: 20px;
}

.app-container {
  max-width: 800px;
  margin: 0 auto;
}

section {
  background: white;
  padding: 25px;
  border-radius: 15px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.05);
  margin-bottom: 30px;
}

h2 {
  color: #2e7d32;
  border-bottom: 2px dashed #a5d6a7;
  padding-bottom: 10px;
  margin-top: 0;
}

/* 話し合いセクションのスタイル */
.ideas-container {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 20px;
}

.idea-btn {
  background-color: #e3f2fd;
  border: 2px solid #90caf9;
  padding: 15px;
  font-size: 18px;
  font-weight: bold;
  border-radius: 10px;
  cursor: pointer;
  text-align: left;
  transition: 0.2s;
}

.idea-btn:hover {
  background-color: #bbdefb;
}

.idea-content {
  background-color: #fff9c4;
  border-left: 5px solid #fbc02d;
  padding: 15px;
  font-size: 16px;
  border-radius: 5px;
  margin-left: 20px;
  line-height: 1.6;
}

.hidden {
  display: none !important;
}

.teacher-summary {
  margin-top: 20px;
  padding: 15px;
  background-color: #e8f5e9;
  border-radius: 10px;
  font-weight: bold;
  color: #1b5e20;
}

/* 練習問題セクションのスタイル */
.quiz-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.quiz-card {
  background: #fafafa;
  border: 1px solid #ddd;
  border-radius: 10px;
  padding: 15px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.quiz-row {
  display: flex;
  align-items: center;
  font-size: 22px;
  font-weight: bold;
}

.quiz-number {
  color: #888;
  font-size: 16px;
  margin-right: 10px;
}

input[type="text"] {
  width: 60px;
  font-size: 20px;
  padding: 5px;
  margin-left: 10px;
  border: 2px solid #ccc;
  border-radius: 5px;
  text-align: center;
  transition: 0.3s;
}

/* 正誤判定のスタイル */
input.correct {
  background-color: #c8e6c9;
  border-color: #4caf50;
  color: #1b5e20;
}

input.incorrect {
  background-color: #ffcdd2;
  border-color: #f44336;
  color: #b71c1c;
}

.hint-btn {
  background-color: #ff9800;
  color: white;
  border: none;
  border-radius: 5px;
  padding: 5px 10px;
  cursor: pointer;
  font-size: 14px;
  margin-left: auto;
}

.hint-btn:hover {
  background-color: #f57c00;
}

.hint-text {
  font-size: 14px;
  color: #d84315;
  background: #ffe0b2;
  padding: 10px;
  border-radius: 5px;
}

/* 全問正解モーダル */
.modal {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(0,0,0,0.7);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

.modal-content {
  background: white;
  padding: 40px;
  border-radius: 20px;
  text-align: center;
  box-shadow: 0 5px 25px rgba(0,0,0,0.3);
  animation: pop 0.5s ease-out;
}

.modal-content h1 {
  color: #e91e63;
  font-size: 36px;
  margin-top: 0;
}

.modal-content p {
  font-size: 24px;
  font-weight: bold;
}

@keyframes pop {
  0% { transform: scale(0.8); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}