:root {
  /* 主色调 - 更年轻活泼的配色 */
  --bg: #f8fafc;
  --fg: #1e293b;
  --muted: #64748b;
  --card: #ffffff;
  --border: #e2e8f0;
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --green: #10b981;
  --green-100: #d1fae5;
  --green-600: #059669;
  --amber: #f59e0b;
  --amber-100: #fef3c7;
  --rose: #ef4444;
  --rose-100: #fee2e2;
  --emerald-100: #d1fae5;
  
  /* 新增颜色 */
  --purple: #8b5cf6;
  --purple-100: #ede9fe;
  --blue-50: #eff6ff;
  --blue-100: #dbeafe;
  
  /* 字体 */
  --font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, Arial, 'Noto Sans', sans-serif;
  
  /* 间距 */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 12px;
  --spacing-lg: 16px;
  --spacing-xl: 24px;
  --spacing-2xl: 32px;
  
  /* 圆角 */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  
  /* 阴影 */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 var(--font-family);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-lg);
}
/* 头部样式 */
header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-sm) var(--spacing-lg);
}

.header-content h1 {
  margin: 0;
  font-size: 24px;
  font-weight: 700;
  color: var(--fg);
  background: linear-gradient(135deg, var(--primary), var(--purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  margin: var(--spacing-xs) 0 0 0;
  font-size: 14px;
  font-weight: 500;
  color: var(--purple);
}

.sub {
  font-size: 12px;
  margin-top: var(--spacing-xs);
  line-height: 1.4;
}

/* 工具栏样式 */
.toolbar {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
  align-items: center;
}

.search-group {
  position: relative;
}

.control-group {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
  align-items: center;
}

input[type="text"] {
  border: 2px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xs) var(--spacing-sm);
  background: var(--card);
  font-size: 13px;
  transition: all 0.2s ease;
  min-width: 180px;
  height: 32px; /* 与按钮高度保持一致 */
  box-sizing: border-box;
}

input[type="text"]:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--blue-100);
}

.btn, label.btn {
  border: 2px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xs) var(--spacing-sm);
  background: var(--card);
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.2s ease;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  height: 32px; /* 与搜索框高度保持一致 */
  box-sizing: border-box;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

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

.btn.green {
  background: var(--green);
  color: white;
  border-color: var(--green);
}

.btn.green:hover {
  background: var(--green-600);
  border-color: var(--green-600);
}

.btn.amber {
  background: var(--amber);
  color: white;
  border-color: var(--amber);
}

.btn.gray {
  background: var(--border);
  color: var(--fg);
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  cursor: pointer;
}

input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
}

/* 进度条样式 */
.progress-section {
  margin-top: 0;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.progress-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--fg);
  margin: 0;
  flex-shrink: 0;
}

.progress {
  height: 12px;
  background: var(--border);
  border-radius: 999px;
  overflow: hidden;
  position: relative;
  flex: 1;
}

.bar {
  height: 100%;
  background: linear-gradient(90deg, var(--green), var(--green-600));
  transition: width 0.3s ease;
  position: relative;
}

.bar::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

.progress-text {
  font-size: 13px;
  font-weight: 600;
  color: var(--green-600);
  margin: 0;
  flex-shrink: 0;
}

/* 周导航样式 */
.week-nav {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: var(--spacing-sm) 0;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(12px);
}

.week-nav-content {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  margin-bottom: var(--spacing-sm);
}

.week-nav-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
  white-space: nowrap;
}

.week-nav-buttons {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
}

.week-nav-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 32px;
  height: 28px;
  padding: 0 var(--spacing-sm);
  background: var(--border);
  color: var(--fg);
  border: none;
  border-radius: var(--radius-md);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

.week-nav-btn:hover {
  background: var(--primary);
  color: white;
  transform: translateY(-1px);
}

.week-nav-btn.active {
  background: var(--primary);
  color: white;
}

.week-nav-btn.completed {
  background: var(--green);
  color: white;
}

/* sticky状态下的样式 */
.week-nav.is-sticky .progress-section {
  margin-top: var(--spacing-xs);
}

.week-nav.is-sticky .progress {
  height: 8px;
}

.week-nav.is-sticky .progress-text {
  font-size: 12px;
  margin: 0;
}

.week-nav.is-sticky .progress-label {
  font-size: 12px;
}

/* 工具栏区域样式 */
.toolbar-section {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: var(--spacing-sm) 0;
}

/* 周和日样式 */
section.week {
  margin: var(--spacing-2xl) 0;
  scroll-margin-top: 120px; /* 为sticky导航和工具栏留出空间 */
}

.week-head {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
  margin-bottom: var(--spacing-md);
}

.week-head h2 {
  margin: 0;
  font-size: 24px;
  font-weight: 600;
  color: var(--fg);
}

.week-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s ease;
}

.week-card:hover {
  box-shadow: var(--shadow-md);
}

.day {
  padding: var(--spacing-lg);
  border-top: 1px solid var(--border);
  transition: background-color 0.2s ease;
}

.day:first-child {
  border-top: none;
}

.day:hover {
  background: var(--blue-50);
}

.day-head {
  display: flex;
  justify-content: space-between;
  gap: var(--spacing-sm);
  align-items: flex-start;
}

.day-head h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
  color: var(--fg);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.w3schools-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  text-decoration: none;
  font-size: 12px;
  font-weight: bold;
  transition: all 0.2s ease;
  flex-shrink: 0;
  cursor: pointer;
}

.w3schools-link:hover {
  background: var(--primary-hover);
  transform: scale(1.1);
  box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3);
}

.w3schools-link:active {
  transform: scale(0.95);
}

.youtube-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background: #ff0000;
  color: white;
  border-radius: 50%;
  text-decoration: none;
  font-size: 12px;
  font-weight: bold;
  transition: all 0.2s ease;
  flex-shrink: 0;
  cursor: pointer;
}

.youtube-link:hover {
  background: #cc0000;
  transform: scale(1.1);
  box-shadow: 0 2px 8px rgba(255, 0, 0, 0.3);
}

.youtube-link:active {
  transform: scale(0.95);
}

.badge {
  font-size: 12px;
  font-weight: 600;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 999px;
  background: var(--border);
  color: var(--muted);
  white-space: nowrap;
}

.badge.done {
  background: var(--emerald-100);
  color: var(--green-600);
}

.muted {
  color: var(--muted);
}

.groups {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
}

.group {
  background: var(--blue-50);
  border: 1px solid var(--blue-100);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  transition: all 0.2s ease;
}

.group:hover {
  background: var(--blue-100);
  transform: translateY(-1px);
}

.group h4 {
  margin: 0 0 var(--spacing-sm) 0;
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.group-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.item {
  display: flex;
  gap: var(--spacing-sm);
  align-items: flex-start;
  padding: var(--spacing-xs) 0;
}

.item + .item {
  border-top: 1px solid var(--border);
  padding-top: var(--spacing-sm);
}

.item input[type="checkbox"] {
  margin-top: 2px;
  flex-shrink: 0;
}

.item label {
  cursor: pointer;
  line-height: 1.5;
  transition: all 0.2s ease;
}

.item label:hover {
  color: var(--primary);
}

.strike {
  text-decoration: line-through;
  color: var(--muted);
  opacity: 0.7;
}

/* 页脚样式 */
footer {
  color: var(--muted);
  padding: var(--spacing-2xl) 0;
  margin-top: var(--spacing-2xl);
  border-top: 1px solid var(--border);
}

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

.learning-tip {
  background: var(--amber-100);
  border: 1px solid var(--amber);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
  font-size: 15px;
  line-height: 1.6;
}

.footer-links {
  font-size: 14px;
}

/* 自检浮条 */
.test-float {
  position: fixed;
  right: var(--spacing-md);
  bottom: var(--spacing-md);
  z-index: 50;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  font-size: 14px;
  font-weight: 500;
  backdrop-filter: blur(8px);
}

.ok {
  background: var(--emerald-100);
  color: var(--green-600);
  border: 1px solid var(--green);
}

.fail {
  background: var(--rose-100);
  color: var(--rose);
  border: 1px solid var(--rose);
}

/* 无障碍样式 */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* 隐藏元素 */
[hidden] {
  display: none !important;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .container {
    padding: var(--spacing-md);
  }
  
  .header-inner {
    flex-direction: column;
    align-items: stretch;
    gap: var(--spacing-md);
  }
  
  .toolbar {
    flex-direction: column;
    align-items: stretch;
  }
  
  .control-group {
    justify-content: center;
  }
  
  input[type="text"] {
    min-width: auto;
    width: 100%;
  }
  
  .groups {
    grid-template-columns: 1fr;
  }
  
  .day-head {
    flex-direction: column;
    align-items: stretch;
    gap: var(--spacing-sm);
  }
  
  .w3schools-link {
    width: 20px;
    height: 20px;
    font-size: 10px;
  }
  
  .youtube-link {
    width: 20px;
    height: 20px;
    font-size: 10px;
  }
  
  .week-nav-content {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-xs);
  }
  
  .week-nav-buttons {
    justify-content: center;
    width: 100%;
  }
  
  .toolbar-section {
    padding: var(--spacing-xs) 0;
  }
  
  .week-nav.is-sticky .progress-section {
    margin-top: var(--spacing-xs);
  }
  
  .progress-section {
    flex-direction: column;
    align-items: stretch;
    gap: var(--spacing-xs);
  }
  
  .progress-label {
    text-align: center;
  }
  
  .progress-text {
    text-align: center;
  }
  
  .header-content h1 {
    font-size: 24px;
  }
  
  .week-head h2 {
    font-size: 20px;
  }
}

@media (max-width: 480px) {
  .header-content h1 {
    font-size: 20px;
  }
  
  .subtitle {
    font-size: 14px;
  }
  
  .btn {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 13px;
  }
  
  .day {
    padding: var(--spacing-md);
  }
  
  .group {
    padding: var(--spacing-sm);
  }
}