/* リセットとベース設定 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Roboto', sans-serif;
  background: linear-gradient(135deg, #0c0c0c 0%, #1a1a2e 50%, #16213e 100%);
  color: #ffffff;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

/* 星空アニメーション */
.stars, .stars2, .stars3 {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
}

.stars {
  background: transparent url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="1" fill="white" opacity="0.8"/></svg>') repeat;
  animation: stars 20s linear infinite;
}

.stars2 {
  background: transparent url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="0.5" fill="white" opacity="0.6"/></svg>') repeat;
  animation: stars 15s linear infinite;
}

.stars3 {
  background: transparent url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="0.3" fill="white" opacity="0.4"/></svg>') repeat;
  animation: stars 10s linear infinite;
}

@keyframes stars {
  0% { transform: translateY(0px); }
  100% { transform: translateY(-1000px); }
}

/* メインコンテナ */
.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 1rem;
  position: relative;
  z-index: 1;
}

/* ヘッダーセクション */
.game-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 1.5rem;
  margin-bottom: 2rem;
  border: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.level-info {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.level-badge {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 15px;
  padding: 0.8rem 1.2rem;
  text-align: center;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.level-number {
  display: block;
  font-family: 'Orbitron', monospace;
  font-size: 1.5rem;
  font-weight: 900;
  color: #ffffff;
}

.level-text {
  display: block;
  font-size: 0.7rem;
  font-weight: 500;
  opacity: 0.8;
}

.exp-bar {
  position: relative;
  width: 150px;
  height: 8px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 4px;
  overflow: hidden;
}

.exp-fill {
  height: 100%;
  background: linear-gradient(90deg, #00d4ff 0%, #0099cc 100%);
  border-radius: 4px;
  transition: width 0.5s ease;
  width: 0%;
}

.exp-text {
  position: absolute;
  top: -20px;
  left: 0;
  font-size: 0.7rem;
  color: #ffffff;
  opacity: 0.8;
}

.stats {
  display: flex;
  gap: 1.5rem;
}

.stat-item {
  text-align: center;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 12px;
  padding: 0.8rem 1rem;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.stat-icon {
  display: block;
  font-size: 1.2rem;
  margin-bottom: 0.3rem;
}

.stat-value {
  display: block;
  font-family: 'Orbitron', monospace;
  font-size: 1.2rem;
  font-weight: 700;
  color: #00d4ff;
}

.stat-label {
  display: block;
  font-size: 0.6rem;
  opacity: 0.7;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* メインゲームエリア */
.game-main {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.question-card {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 2rem;
  border: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  animation: slideInUp 0.6s ease;
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.question-header {
  margin-bottom: 1.5rem;
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 1rem;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #00ff88 0%, #00cc6a 100%);
  border-radius: 3px;
  transition: width 0.5s ease;
  width: 10%;
}

.question-counter {
  text-align: center;
  font-family: 'Orbitron', monospace;
  font-size: 0.9rem;
  color: #00ff88;
  font-weight: 500;
}

.question-content {
  text-align: center;
}

.question {
  font-size: 1.3rem;
  line-height: 1.6;
  color: #ffffff;
}

.question p {
  margin-bottom: 1rem;
}

.question strong {
  color: #00ff88;
  font-weight: 700;
}

/* 選択肢コンテナ */
.choices-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.choices {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
}

.choice-btn {
  background: rgba(255, 255, 255, 0.1);
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 15px;
  padding: 1.2rem 1.5rem;
  font-size: 1.1rem;
  color: #ffffff;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(5px);
  font-weight: 500;
  position: relative;
  overflow: hidden;
}

.choice-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s;
}

.choice-btn:hover::before {
  left: 100%;
}

.choice-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: #00ff88;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 255, 136, 0.3);
}

.choice-btn:disabled {
  opacity: 0.6;
  cursor: default;
  transform: none;
}

.choice-btn.correct {
  background: linear-gradient(135deg, #00ff88 0%, #00cc6a 100%);
  border-color: #00ff88;
  color: #000000;
  font-weight: 700;
  animation: correctPulse 0.6s ease;
}

.choice-btn.incorrect {
  background: linear-gradient(135deg, #ff4757 0%, #ff3742 100%);
  border-color: #ff4757;
  color: #ffffff;
  animation: incorrectShake 0.6s ease;
}

@keyframes correctPulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

@keyframes incorrectShake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

/* 結果コンテナ */
.result-container {
  min-height: 120px;
}

.result {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-radius: 15px;
  padding: 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.2);
  animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.explain-block {
  text-align: left;
}

.explain-block .title {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.explain-block .line {
  margin-bottom: 0.8rem;
  line-height: 1.5;
}

.explain-block strong {
  color: #00ff88;
}

.correct {
  border-left: 4px solid #00ff88;
  padding-left: 1rem;
}

.incorrect {
  border-left: 4px solid #ff4757;
  padding-left: 1rem;
}

/* アクションボタン */
.action-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
}

.action-btn {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border: none;
  border-radius: 12px;
  padding: 1rem 2rem;
  font-size: 1.1rem;
  color: #ffffff;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.action-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.6);
}

.btn-icon {
  font-size: 1.2rem;
}

.restart-btn {
  background: linear-gradient(135deg, #ff6b6b 0%, #ee5a52 100%);
  box-shadow: 0 4px 15px rgba(255, 107, 107, 0.4);
}

.restart-btn:hover {
  box-shadow: 0 8px 25px rgba(255, 107, 107, 0.6);
}

/* 通知 */
.achievement-notification,
.levelup-notification {
  position: fixed;
  top: 20px;
  right: 20px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-radius: 15px;
  padding: 1.5rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.2);
  z-index: 1000;
  animation: slideInRight 0.5s ease;
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(100%);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.achievement-content,
.levelup-content {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.achievement-icon,
.levelup-icon {
  font-size: 2rem;
}

.achievement-text,
.levelup-text {
  color: #333;
}

.achievement-title,
.levelup-title {
  font-weight: 700;
  font-size: 1.1rem;
  margin-bottom: 0.3rem;
}

.achievement-desc,
.levelup-level {
  font-size: 0.9rem;
  opacity: 0.8;
}

/* レスポンシブデザイン */
@media screen and (max-width: 768px) {
  .container {
    padding: 0.5rem;
  }
  
  .game-header {
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
  }
  
  .level-info {
    width: 100%;
    justify-content: center;
  }
  
  .stats {
    width: 100%;
    justify-content: space-around;
  }
  
  .choices {
    grid-template-columns: 1fr;
  }
  
  .question-card {
    padding: 1.5rem;
  }
  
  .question {
    font-size: 1.1rem;
  }
  
  .choice-btn {
    padding: 1rem;
    font-size: 1rem;
  }
  
  .action-buttons {
    flex-direction: column;
  }
  
  .action-btn {
    width: 100%;
    justify-content: center;
  }
}

@media screen and (max-width: 480px) {
  .level-badge {
    padding: 0.6rem 1rem;
  }
  
  .level-number {
    font-size: 1.2rem;
  }
  
  .exp-bar {
    width: 120px;
  }
  
  .stat-item {
    padding: 0.6rem 0.8rem;
  }
  
  .stat-value {
    font-size: 1rem;
  }
  
  .question-card {
    padding: 1rem;
  }
  
  .question {
    font-size: 1rem;
  }
  
  .choice-btn {
    padding: 0.8rem;
    font-size: 0.9rem;
  }
}