/**
 * 记忆配对游戏 - 样式表
 * 响应式设计，支持桌面和移动端
 */

/* ========== CSS 变量 ========== */
:root {
  --primary-color: #667eea;
  --primary-dark: #5a67d8;
  --secondary-color: #764ba2;
  --success-color: #48bb78;
  --warning-color: #ed8936;
  --danger-color: #f56565;
  --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --card-back-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --card-bg: #ffffff;
  --text-primary: #2d3748;
  --text-secondary: #718096;
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.1);
  --border-radius: 16px;
  --card-radius: 12px;
}

/* ========== 基础样式 ========== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-gradient);
  min-height: 100vh;
  color: var(--text-primary);
  overflow-x: hidden;
}

.game-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 16px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ========== 游戏头部 ========== */
.game-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
  padding: 16px;
  background: rgba(255, 255, 255, 0.95);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-md);
}

.score-panel {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.score-item {
  text-align: center;
}

.score-label {
  font-size: 12px;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.score-value {
  font-size: 24px;
  font-weight: bold;
  color: var(--primary-color);
  min-width: 60px;
}

.score-item.high-score .score-value {
  color: var(--warning-color);
}

.control-buttons {
  display: flex;
  gap: 10px;
}

.btn {
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-secondary {
  background: var(--text-secondary);
  color: white;
}

.btn-secondary:hover {
  background: #4a5568;
  transform: translateY(-2px);
}

.btn-home {
  background: var(--primary-color);
  color: white;
}

.btn-home:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
}

/* ========== 游戏区域 ========== */
.game-area {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  padding: 20px;
}

.board {
  display: grid;
  gap: 12px;
  padding: 20px;
  background: rgba(255, 255, 255, 0.95);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-lg);
  max-width: 100%;
}

/* 不同难度的网格布局 */
.board[data-size="16"] {
  grid-template-columns: repeat(4, 1fr);
}

.board[data-size="24"] {
  grid-template-columns: repeat(4, 1fr);
}

.board[data-size="32"] {
  grid-template-columns: repeat(4, 1fr);
}

.board[data-size="40"] {
  grid-template-columns: repeat(5, 1fr);
}

/* ========== 卡片样式 ========== */
.card {
  width: 70px;
  height: 70px;
  perspective: 1000px;
  cursor: pointer;
  position: relative;
}

.card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
}

.card.flipped .card-inner {
  transform: rotateY(180deg);
}

.card.matched .card-inner {
  animation: matchPulse 0.5s ease;
}

@keyframes matchPulse {
  0%, 100% { transform: rotateY(180deg) scale(1); }
  50% { transform: rotateY(180deg) scale(1.1); }
}

.card-front,
.card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: var(--card-radius);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 36px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.card-back {
  background: var(--card-back-gradient);
  background-size: 200% 200%;
  animation: gradientShift 3s ease infinite;
}

.card-back::after {
  content: '?';
  font-size: 28px;
  color: white;
  font-weight: bold;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.card-front {
  background: var(--card-bg);
  transform: rotateY(180deg);
}

.card.matched .card-front {
  background: var(--success-color);
  box-shadow: 0 0 20px rgba(72, 187, 120, 0.5);
}

/* ========== 游戏覆盖层 ========== */
.game-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.85);
  border-radius: var(--border-radius);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 100;
  backdrop-filter: blur(4px);
}

.overlay-content {
  text-align: center;
  padding: 40px;
  color: white;
  max-width: 500px;
}

.overlay-title {
  font-size: 36px;
  font-weight: bold;
  margin-bottom: 12px;
  background: linear-gradient(135deg, #fff 0%, #e2e8f0 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.overlay-subtitle {
  font-size: 18px;
  color: #cbd5e0;
  margin-bottom: 30px;
}

/* 难度选择 */
.difficulty-selector {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-bottom: 30px;
}

.difficulty-btn {
  padding: 12px 24px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

.difficulty-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.5);
  transform: translateY(-2px);
}

.difficulty-btn.active {
  background: var(--success-color);
  border-color: var(--success-color);
}

.difficulty-btn span {
  display: block;
  font-size: 11px;
  opacity: 0.8;
  margin-top: 4px;
}

/* 主题选择 */
.theme-selector {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-bottom: 30px;
}

.theme-btn {
  padding: 12px 20px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 8px;
}

.theme-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.5);
  transform: translateY(-2px);
}

.theme-btn.active {
  background: var(--warning-color);
  border-color: var(--warning-color);
}

/* 开始按钮 */
.btn-start {
  padding: 16px 48px;
  background: linear-gradient(135deg, var(--success-color) 0%, #38a169 100%);
  color: white;
  border: none;
  border-radius: 12px;
  font-size: 18px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 20px rgba(72, 187, 120, 0.4);
}

.btn-start:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 30px rgba(72, 187, 120, 0.6);
}

.btn-restart {
  padding: 16px 48px;
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  color: white;
  border: none;
  border-radius: 12px;
  font-size: 18px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s ease;
  margin: 10px;
}

.btn-restart:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 30px rgba(102, 126, 234, 0.6);
}

/* 结算统计 */
.game-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 30px 0;
}

.stat-item {
  background: rgba(255, 255, 255, 0.1);
  padding: 16px;
  border-radius: 12px;
}

.stat-label {
  font-size: 12px;
  color: #cbd5e0;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.stat-value {
  font-size: 28px;
  font-weight: bold;
  color: white;
}

.stat-stars {
  font-size: 36px;
  margin: 20px 0;
}

/* ========== 移动端提示 ========== */
.mobile-hint {
  text-align: center;
  color: rgba(255, 255, 255, 0.8);
  font-size: 14px;
  margin-top: 16px;
  padding: 12px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 8px;
}

/* ========== 暂停指示器 ========== */
.pause-indicator {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(0, 0, 0, 0.8);
  color: white;
  padding: 20px 40px;
  border-radius: 12px;
  font-size: 24px;
  font-weight: bold;
  z-index: 50;
  display: none;
}

.pause-indicator.visible {
  display: block;
}

/* ========== 响应式设计 ========== */
@media (max-width: 768px) {
  .game-container {
    padding: 12px;
  }
  
  .game-header {
    padding: 12px;
    flex-direction: column;
    align-items: stretch;
  }
  
  .score-panel {
    justify-content: center;
    gap: 16px;
  }
  
  .score-value {
    font-size: 20px;
  }
  
  .control-buttons {
    justify-content: center;
  }
  
  .card {
    width: 60px;
    height: 60px;
  }
  
  .card-front {
    font-size: 28px;
  }
  
  .board {
    gap: 8px;
    padding: 12px;
  }
  
  .overlay-title {
    font-size: 28px;
  }
  
  .overlay-subtitle {
    font-size: 16px;
  }
  
  .difficulty-btn,
  .theme-btn {
    padding: 10px 16px;
    font-size: 13px;
  }
  
  .game-stats {
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
  }
  
  .stat-item {
    padding: 12px 8px;
  }
  
  .stat-value {
    font-size: 22px;
  }
}

@media (max-width: 480px) {
  .card {
    width: 50px;
    height: 50px;
  }
  
  .card-front {
    font-size: 24px;
  }
  
  .board[data-size="40"] {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .score-panel {
    gap: 12px;
  }
  
  .score-value {
    font-size: 18px;
    min-width: 50px;
  }
}

/* ========== 横屏优化 ========== */
@media (max-height: 600px) and (orientation: landscape) {
  .game-container {
    padding: 8px;
  }
  
  .game-header {
    margin-bottom: 12px;
    padding: 10px;
  }
  
  .score-panel {
    gap: 12px;
  }
  
  .score-label {
    font-size: 10px;
  }
  
  .score-value {
    font-size: 18px;
  }
  
  .board {
    padding: 12px;
    gap: 8px;
  }
  
  .card {
    width: 55px;
    height: 55px;
  }
}

/* ========== 动画效果 ========== */
@keyframes cardFlip {
  0% { transform: rotateY(0deg); }
  100% { transform: rotateY(180deg); }
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.overlay-content {
  animation: fadeIn 0.4s ease;
}

/* ========== 辅助类 ========== */
.hidden {
  display: none !important;
}

.visible {
  display: flex !important;
}