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

:root {
  --bg: #f8fafc;
  --text: #0f172a;
  --text-secondary: #64748b;
  --border: #e2e8f0;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --accent: #f97316;
  --card-bg: #ffffff;
  --card-shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --card-shadow-hover: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --radius: 12px;
}

/* 深色模式 */
[data-theme="dark"] {
  --bg: #0b1120;
  --text: #e2e8f0;
  --text-secondary: #94a3b8;
  --border: #1e293b;
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --primary-light: #172554;
  --accent: #fb923c;
  --card-bg: #1e293b;
  --card-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.3);
  --card-shadow-hover: 0 10px 15px -3px rgb(0 0 0 / 0.4);
}

body {
  font-family: 'Inter', system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  transition: background 0.3s ease, color 0.3s ease;
  -webkit-font-smoothing: antialiased;
}

/* 统一按钮和输入框字体 */
button,
input,
select,
textarea {
  font-family: inherit;
}

/* 头部 */
.header {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background-color: transparent;
  /* 支持背景模糊 */
}

/* 深色模式下的头部背景 */
[data-theme="dark"] .header {
  background-color: rgba(30, 41, 59, 0.8);
}

[data-theme="light"] .header {
  background-color: rgba(255, 255, 255, 0.8);
}

.header-inner {
  max-width: 1024px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 20px;
  font-weight: 600;
  color: var(--primary);
  text-decoration: none;
}

.nav {
  display: flex;
  gap: 24px;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  padding: 8px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

.nav-link:hover,
.nav-link.active {
  color: var(--text);
  border-bottom-color: var(--primary);
}

/* 主内容区 */
main {
  max-width: 1024px;
  margin: 0 auto;
  padding: 40px 24px;
}

/* 首页 */
.home {
  text-align: center;
  padding: 80px 0;
}

.home h1 {
  font-size: 32px;
  font-weight: 600;
  margin-bottom: 16px;
}

.home p {
  color: var(--text-secondary);
  font-size: 16px;
  margin-bottom: 24px;
}

/* 首页词汇统计 */
.vocab-stats {
  margin: 32px 0;
  padding: 24px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  max-width: 400px;
  margin-left: auto;
  margin-right: auto;
}

.stats-loading {
  color: var(--text-secondary);
  font-size: 14px;
}

.stats-card {
  margin-bottom: 16px;
}

.stats-number {
  font-size: 48px;
  font-weight: 600;
  color: var(--primary);
  line-height: 1;
}

.stats-label {
  color: var(--text-secondary);
  font-size: 14px;
  margin-top: 8px;
}

.stats-info {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.6;
}

.home .btn-start {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  padding: 14px 32px;
  border-radius: var(--radius);
  text-decoration: none;
  font-weight: 500;
  font-size: 16px;
  transition: background 0.2s;
}

.home .btn-start:hover {
  background: #1d4ed8;
}

/* 学习页面 */
.learn-page h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 20px;
}

/* 分类网格 */
.categories {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 40px;
}

.category-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: var(--card-shadow);
}

.category-card:hover {
  border-color: var(--primary);
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-2px);
}

.category-card.active {
  border-color: var(--primary);
  background: var(--primary-light);
}

.category-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.category-card span {
  color: var(--text-secondary);
  font-size: 13px;
}

/* 发音模式列表 */
.patterns {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 32px;
}

.pattern-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 8px 16px;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.2s;
}

.pattern-chip:hover {
  border-color: var(--primary);
}

.pattern-chip.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.pattern-chip .ipa {
  color: var(--text-secondary);
  font-size: 13px;
}

.pattern-chip.active .ipa {
  color: rgba(255, 255, 255, 0.8);
}

/* 练习区域 */
.practice-area {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--card-shadow);
}

.practice-header {
  text-align: center;
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

.word-count {
  text-align: center;
  color: var(--text-secondary);
  font-size: 14px;
  margin-bottom: 20px;
}

.practice-header .pattern {
  font-size: 48px;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 8px;
}

.practice-header .ipa {
  font-size: 24px;
  color: var(--text-secondary);
}

.practice-header .play-btn {
  margin-top: 16px;
  background: none;
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 48px;
  height: 48px;
  cursor: pointer;
  font-size: 18px;
  transition: all 0.2s;
}

.practice-header .play-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

/* 单词列表 */
.word-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 16px;
}

.word-card {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 16px;
  cursor: pointer;
  transition: all 0.2s;
  border: 1px solid transparent;
}

.word-card:hover {
  background: var(--primary-light);
}

.word-card .word {
  font-size: 20px;
  font-weight: 500;
  margin-bottom: 4px;
}

.word-card .word .highlight {
  color: var(--accent);
  font-weight: 600;
}

.word-card .meaning {
  color: var(--text-secondary);
  font-size: 13px;
}

.word-card .phonetic {
  color: var(--text-secondary);
  font-size: 12px;
  margin-top: 4px;
}

/* 加载更多 */
.load-more {
  text-align: center;
  margin-top: 24px;
}

.load-more button {
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 24px;
  cursor: pointer;
  font-size: 14px;
  color: var(--text-secondary);
  transition: all 0.2s;
}

.load-more button:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.load-more .ai-btn {
  background: var(--primary);
  border: none;
  color: #fff;
  margin-left: 12px;
}

.load-more .ai-btn:hover {
  background: #1d4ed8;
  color: #fff;
}

.load-more .clear-btn {
  background: none;
  border: 1px solid #ff4d4f;
  color: #ff4d4f;
  margin-left: 12px;
}

.load-more .clear-btn:hover {
  background: #fff1f0;
  border-color: #ff7875;
  color: #ff7875;
}

/* 空状态 */
.empty {
  text-align: center;
  padding: 40px;
  color: var(--text-secondary);
}

/* 加载状态 */
.loading {
  text-align: center;
  padding: 40px;
  color: var(--text-secondary);
}

/* 响应式 - 平板 */
@media (max-width: 768px) {
  .header-inner {
    padding: 0 16px;
    height: 56px;
  }

  .nav {
    gap: 16px;
  }

  .nav-link {
    font-size: 13px;
  }

  main {
    padding: 24px 16px;
  }

  .practice-area {
    padding: 24px 16px;
  }
}

/* 响应式 - 手机 */
@media (max-width: 640px) {

  /* PWA 安全区域 */
  body {
    padding-top: env(safe-area-inset-top);
    padding-bottom: env(safe-area-inset-bottom);
    padding-left: env(safe-area-inset-left);
    padding-right: env(safe-area-inset-right);
  }

  .home {
    padding: 40px 0;
  }

  .home h1 {
    font-size: 24px;
  }

  .home p {
    font-size: 14px;
  }

  .categories {
    grid-template-columns: 1fr;
  }

  .category-card {
    padding: 16px;
  }

  .patterns {
    gap: 8px;
  }

  .pattern-chip {
    padding: 6px 12px;
    font-size: 13px;
  }

  .practice-header .pattern {
    font-size: 36px;
  }

  .practice-header .ipa {
    font-size: 20px;
  }

  .word-list {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }

  .word-card {
    padding: 12px;
    /* 移动端改为垂直布局 */
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    min-height: auto;
  }

  .word-card .word {
    font-size: 18px;
    margin-bottom: 6px;
  }

  .word-card .phonetic {
    font-size: 13px;
    margin-bottom: 4px;
  }

  .word-card .meaning {
    font-size: 12px;
    line-height: 1.4;
  }

  /* 触控优化 - 增大点击区域 */
  .pattern-chip,
  .category-card,
  .limit-btn,
  .shuffle-btn {
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .nav-link {
    padding: 12px 8px;
  }

  /* 词数选择器移动端优化 */
  .limit-selector {
    gap: 6px;
  }

  .limit-btn {
    padding: 8px 12px;
    font-size: 13px;
  }

  .shuffle-btn {
    margin-left: 4px;
    padding: 8px 12px;
    font-size: 13px;
  }

  /* 底部留白，避免被手机底部操作条遮挡 */
  main {
    padding-bottom: 80px;
  }

  /* 统计卡片 */
  .vocab-stats {
    margin: 24px 0;
    padding: 20px;
  }

  .stats-number {
    font-size: 40px;
  }
}

/* 设置按钮 */
.settings-btn {
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 4px;
  transition: background 0.2s;
}

.settings-btn:hover {
  background: var(--primary-light);
}

/* 弹窗 */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal-content {
  background: var(--card-bg);
  border-radius: var(--radius);
  width: 90%;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--card-shadow-hover);
  border: 1px solid var(--border);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 {
  font-size: 18px;
  font-weight: 600;
}

.close-btn {
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 0 8px;
}

.close-btn:hover {
  color: var(--text);
}

.modal-body {
  padding: 24px;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 12px;
  justify-content: flex-end;
}

/* 隐私声明 */
.privacy-notice {
  background: #f0f9ff;
  border: 1px solid #bae6fd;
  border-radius: 8px;
  padding: 16px;
  margin-bottom: 24px;
}

.privacy-notice h3 {
  font-size: 14px;
  margin-bottom: 8px;
  color: #0369a1;
}

.privacy-notice ul {
  list-style: none;
  font-size: 13px;
  line-height: 1.8;
}

.privacy-notice li {
  margin-bottom: 4px;
}

/* 模型信息 */
.model-info {
  background: #f5f5f5;
  padding: 12px 16px;
  border-radius: 6px;
  font-size: 14px;
  color: var(--text-secondary);
}

.model-info strong {
  color: var(--primary);
}

/* 表单 */
.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 6px;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 15px;
  background: var(--bg);
  color: var(--text);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.form-group small {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  color: var(--text-secondary);
}

.form-group small a {
  color: var(--primary);
}

/* 按钮 */
/* 按钮 */
.btn-primary {
  background: var(--primary);
  color: white;
  border: none;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-size: 15px;
  cursor: pointer;
  font-weight: 500;
  transition: background 0.2s;
  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

.btn-primary:hover {
  background: var(--primary-hover);
}

.btn-secondary {
  background: none;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  padding: 10px 20px;
  border-radius: 6px;
  font-size: 14px;
  cursor: pointer;
}

.btn-secondary:hover {
  background: #f5f5f5;
}

/* 自动扩词状态面板 */
.auto-expand-status {
  background: #f5f5f5;
  border-radius: 8px;
  padding: 16px;
  margin-top: 16px;
}

.status-item {
  padding: 8px 0;
  border-bottom: 1px solid #e0e0e0;
  font-size: 14px;
}

.status-item:last-child {
  border-bottom: none;
}

.status-item span {
  font-weight: 600;
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* 词数控制区 */
.word-controls {
  text-align: center;
  margin-bottom: 20px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}

.word-controls .word-count {
  margin-bottom: 12px;
}

.limit-selector {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
}

.limit-selector span {
  color: var(--text-secondary);
  font-size: 14px;
}

.limit-btn {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 14px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
}

.limit-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.limit-btn.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.shuffle-btn {
  background: none;
  border: 1px solid var(--primary);
  color: var(--primary);
  border-radius: 6px;
  padding: 6px 14px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
  margin-left: 8px;
}

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

/* 深色模式补充样式 */
[data-theme="dark"] .privacy-notice {
  background: rgba(30, 58, 138, 0.4);
  border-color: #1e40af;
}

[data-theme="dark"] .privacy-notice h3 {
  color: #60a5fa;
}

[data-theme="dark"] input:focus,
[data-theme="dark"] select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.3);
}

/* 主题切换按钮 */
.theme-btn {
  min-width: 36px;
}

/* 过渡效果 */
.header,
.category-card,
.pattern-chip,
.practice-area,
.word-card,
.modal-content,
input,
select {
  transition: background 0.3s, border-color 0.3s, color 0.3s;
}

/* 分类介绍区域 */
.category-intro {
  margin-bottom: 24px;
}

.category-description {
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--bg) 100%);
  border: 1px solid var(--border);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.category-description .desc-text {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  margin: 0;
}

.category-description .desc-tip {
  font-size: 13px;
  color: var(--text-secondary);
  margin: 8px 0 0 0;
  padding-top: 8px;
  border-top: 1px dashed var(--border);
}

/* 发音规则说明区域 */
.rule-section {
  background: linear-gradient(135deg, #fef3c7 0%, #fffbeb 100%);
  border: 1px solid #fcd34d;
  border-radius: var(--radius);
  padding: 16px 20px;
  margin-bottom: 24px;
  text-align: left;
}

[data-theme="dark"] .rule-section {
  background: linear-gradient(135deg, rgba(251, 191, 36, 0.15) 0%, rgba(251, 191, 36, 0.05) 100%);
  border-color: rgba(251, 191, 36, 0.4);
}

.rule-text {
  font-size: 15px;
  line-height: 1.7;
  color: #92400e;
  font-weight: 500;
}

[data-theme="dark"] .rule-text {
  color: #fcd34d;
}

.rule-tip {
  font-size: 13px;
  color: #b45309;
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px dashed rgba(180, 83, 9, 0.3);
}

[data-theme="dark"] .rule-tip {
  color: #fbbf24;
  border-top-color: rgba(251, 191, 36, 0.3);
}