/* === WorkBuddy Academy — 清新治愈风 === */
:root {
  --green-primary: #7C9A6E;
  --green-light: #B8D4A8;
  --green-pale: #E8F0E4;
  --green-dark: #5A7A4E;
  --bg: #FAFBF8;
  --bg-card: #FFFFFF;
  --text: #2C3338;
  --text-secondary: #6B7C7C;
  --text-muted: #9BA8A8;
  --border: #E5EBE5;
  --shadow: 0 2px 12px rgba(0,0,0,0.06);
  --shadow-hover: 0 4px 20px rgba(0,0,0,0.10);
  --radius: 12px;
  --radius-sm: 8px;
  --sidebar-width: 380px;
  --topbar-height: 56px;
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", Menlo, Monaco, monospace;
  --transition: 0.2s ease;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  overflow: hidden;
  height: 100vh;
}

/* === Layout === */
.app { display: flex; height: 100vh; }

/* === Sidebar === */
.sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--bg-card);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  transition: transform var(--transition);
  z-index: 100;
}
.sidebar-header {
  padding: 18px 16px 14px;
  border-bottom: 1px solid var(--border);
}
.sidebar-logo {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--green-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}
.sidebar-logo .icon { font-size: 1.4rem; }
.sidebar-subtitle {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 2px;
}
.sidebar-progress {
  margin-top: 12px;
}
.progress-bar {
  height: 4px;
  background: var(--green-pale);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 4px;
}
.progress-fill {
  height: 100%;
  background: var(--green-primary);
  border-radius: 2px;
  transition: width 0.4s ease;
}
.progress-text { font-size: 0.7rem; color: var(--text-muted); }

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 8px 0;
}
.sidebar-nav::-webkit-scrollbar { width: 4px; }
.sidebar-nav::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.section-group { margin-bottom: 2px; }
.section-toggle {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border: none;
  background: none;
  cursor: pointer;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text);
  font-family: inherit;
  transition: background var(--transition);
  text-align: left;
}
.section-toggle:hover { background: var(--green-pale); }
.section-toggle .emoji { font-size: 1rem; width: 24px; text-align: center; }
.section-toggle .arrow {
  margin-left: auto;
  font-size: 0.6rem;
  transition: transform var(--transition);
  color: var(--text-muted);
}
.section-group.collapsed .section-toggle .arrow { transform: rotate(-90deg); }
.section-group.collapsed .chapter-list { display: none; }

.chapter-list { padding: 0 0 8px; }
.chapter-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 16px;
  font-size: 0.87rem;
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--transition);
  border-left: 3px solid transparent;
  position: relative;
}
.chapter-link:hover {
  background: var(--green-pale);
  color: var(--text);
}
.chapter-link.active {
  background: var(--green-pale);
  color: var(--green-dark);
  font-weight: 600;
  border-left-color: var(--green-primary);
}
.chapter-link .ch-num {
  font-size: 0.7rem;
  color: var(--text-muted);
  min-width: 20px;
}
.chapter-link .check-icon {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.6rem;
  flex-shrink: 0;
  transition: all var(--transition);
}
.chapter-link.completed .check-icon {
  background: var(--green-primary);
  border-color: var(--green-primary);
  color: white;
}
.chapter-link.completed { opacity: 0.8; }

.sidebar-footer {
  padding: 12px 16px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 8px;
}
.sidebar-footer button {
  flex: 1;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  cursor: pointer;
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-family: inherit;
  transition: all var(--transition);
}
.sidebar-footer button:hover { background: var(--green-pale); color: var(--text); }

/* === Main Content === */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* === Top Bar === */
.topbar {
  height: var(--topbar-height);
  min-height: var(--topbar-height);
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 24px;
  gap: 16px;
}
.menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.3rem;
  cursor: pointer;
  padding: 4px;
  color: var(--text);
}
.search-box {
  flex: 1;
  max-width: 400px;
  position: relative;
}
.search-box input {
  width: 100%;
  padding: 8px 16px 8px 36px;
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.85rem;
  font-family: inherit;
  background: var(--bg);
  outline: none;
  transition: all var(--transition);
}
.search-box input:focus {
  border-color: var(--green-primary);
  box-shadow: 0 0 0 3px var(--green-pale);
}
.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 0.85rem;
  pointer-events: none;
}
.topbar-actions { display: flex; gap: 8px; margin-left: auto; }
.topbar-actions button {
  width: 36px;
  height: 36px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--bg-card);
  cursor: pointer;
  font-size: 1rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}
.topbar-actions button:hover { background: var(--green-pale); color: var(--text); }
.chapter-indicator {
  font-size: 0.75rem;
  color: var(--text-muted);
  white-space: nowrap;
}

/* === Search Dropdown === */
.search-results {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-top: 4px;
  max-height: 300px;
  overflow-y: auto;
  box-shadow: var(--shadow);
  display: none;
  z-index: 200;
}
.search-results.show { display: block; }
.search-result-item {
  padding: 10px 16px;
  cursor: pointer;
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}
.search-result-item:hover { background: var(--green-pale); }
.search-result-item .sr-title { font-weight: 600; font-size: 0.85rem; }
.search-result-item .sr-section { font-size: 0.7rem; color: var(--text-muted); }
.search-result-item .sr-context {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 2px;
  line-height: 1.4;
}
.search-result-item .sr-context mark {
  background: #D4E8C4;
  color: var(--text);
  padding: 0 2px;
  border-radius: 2px;
}

/* === Content Area === */
.content {
  flex: 1;
  overflow-y: auto;
  padding: 0 48px 64px;
}
.content::-webkit-scrollbar { width: 6px; }
.content::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* Home / Welcome */
.welcome {
  max-width: 720px;
  margin: 0 auto;
  padding-top: 64px;
}
.welcome-hero {
  text-align: center;
  margin-bottom: 48px;
}
.welcome-hero .hero-icon { font-size: 4rem; margin-bottom: 16px; }
.welcome-hero h1 {
  font-size: 2rem;
  color: var(--green-dark);
  margin-bottom: 8px;
  font-weight: 700;
}
.welcome-hero p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.8;
}
.welcome-stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-bottom: 40px;
}
.stat-card {
  text-align: center;
  padding: 16px 24px;
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  min-width: 100px;
}
.stat-card .stat-num {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--green-primary);
}
.stat-card .stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 4px;
}

.section-preview { margin-bottom: 40px; }
.section-preview h2 {
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 12px;
  padding-left: 4px;
}
.preview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 10px;
}
.preview-card {
  padding: 14px 16px;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  color: var(--text);
}
.preview-card:hover {
  border-color: var(--green-light);
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}
.preview-card .pc-num { font-size: 0.7rem; color: var(--text-muted); margin-bottom: 4px; }
.preview-card .pc-title { font-size: 0.9rem; font-weight: 600; color: var(--text); }

/* Chapter Content */
.chapter-view {
  max-width: 780px;
  margin: 0 auto;
  padding-top: 40px;
}
.chapter-header {
  margin-bottom: 32px;
  padding-bottom: 20px;
  border-bottom: 2px solid var(--green-pale);
}
.chapter-header .ch-section-label {
  font-size: 0.8rem;
  color: var(--green-primary);
  font-weight: 600;
  margin-bottom: 6px;
}
.chapter-header h1 {
  font-size: 1.8rem;
  color: var(--text);
  font-weight: 700;
  line-height: 1.4;
}
.chapter-header .ch-meta {
  margin-top: 8px;
  font-size: 0.78rem;
  color: var(--text-muted);
}
.chapter-body {
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--text);
}
.chapter-body h1 { font-size: 1.5rem; margin: 28px 0 12px; color: var(--text); }
.chapter-body h2 {
  font-size: 1.2rem;
  margin: 24px 0 10px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border);
  color: var(--green-dark);
}
.chapter-body h3 { font-size: 1.05rem; margin: 20px 0 8px; color: var(--text); }
.chapter-body h4 { font-size: 0.95rem; margin: 16px 0 6px; }
.chapter-body p { margin: 10px 0; }
.chapter-body ul, .chapter-body ol { margin: 8px 0 8px 20px; }
.chapter-body li { margin: 4px 0; }
.chapter-body strong { color: var(--green-dark); }
.chapter-body code {
  background: var(--green-pale);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.88em;
  color: var(--green-dark);
}
.chapter-body pre {
  background: #F5F7F4;
  padding: 16px 20px;
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin: 12px 0;
  border: 1px solid var(--border);
  font-size: 0.85em;
}
.chapter-body pre code {
  background: none;
  padding: 0;
  color: var(--text);
}
.chapter-body blockquote {
  margin: 12px 0;
  padding: 12px 16px;
  border-left: 4px solid var(--green-light);
  background: var(--green-pale);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-secondary);
}
.chapter-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0;
  font-size: 0.9em;
}
.chapter-body th, .chapter-body td {
  padding: 8px 12px;
  border: 1px solid var(--border);
  text-align: left;
}
.chapter-body th { background: var(--green-pale); font-weight: 600; }
.chapter-body hr { border: none; border-top: 1px solid var(--border); margin: 20px 0; }
.chapter-body a { color: var(--green-dark); text-decoration: underline; }
.chapter-body a:hover { color: var(--green-primary); }
.chapter-body img { max-width: 100%; border-radius: var(--radius-sm); }

/* Chapter Footer */
.chapter-footer {
  margin-top: 48px;
  padding: 24px 0;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}
.chapter-footer .nav-btn {
  padding: 10px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  cursor: pointer;
  font-family: inherit;
  font-size: 0.85rem;
  color: var(--text-secondary);
  transition: all var(--transition);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 6px;
}
.chapter-footer .nav-btn:hover {
  border-color: var(--green-primary);
  color: var(--green-primary);
  background: var(--green-pale);
}
.chapter-footer .nav-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.complete-btn {
  padding: 10px 20px;
  border: 2px solid var(--green-primary);
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  cursor: pointer;
  font-family: inherit;
  font-size: 0.85rem;
  color: var(--green-primary);
  transition: all var(--transition);
}
.complete-btn:hover { background: var(--green-primary); color: white; }
.complete-btn.done { background: var(--green-primary); color: white; border-color: var(--green-primary); }
.complete-btn.done:hover { background: var(--bg-card); color: var(--green-primary); }

/* About page */
.about-view {
  max-width: 780px;
  margin: 0 auto;
  padding-top: 40px;
}
.about-view h1 { font-size: 1.8rem; color: var(--text); margin-bottom: 24px; }
.about-view h2 { font-size: 1.2rem; color: var(--green-dark); margin: 20px 0 10px; }

/* === Overlay (mobile sidebar) === */
.overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.3);
  z-index: 99;
}
.overlay.show { display: block; }

/* === Theme: Dark === */
body.dark {
  --bg: #1A1D1C;
  --bg-card: #242826;
  --text: #E0E4E2;
  --text-secondary: #A0A8A4;
  --text-muted: #6B7470;
  --border: #363C38;
  --green-primary: #8BB87A;
  --green-light: #5A7A4E;
  --green-pale: #2A332A;
  --green-dark: #A0D090;
  --shadow: 0 2px 12px rgba(0,0,0,0.2);
  --shadow-hover: 0 4px 20px rgba(0,0,0,0.3);
}
body.dark .chapter-body pre { background: #1E2220; }
body.dark .chapter-body code { color: var(--green-dark); }
body.dark .chapter-body blockquote { background: #2A332A; }
body.dark .chapter-body th { background: #2A332A; }
body.dark .chapter-body a { color: var(--green-dark); }
body.dark .search-result-item .sr-context mark { background: #4A6A3A; }

/* === Empty State === */
.empty-state {
  text-align: center;
  padding: 80px 20px;
  color: var(--text-muted);
}
.empty-state .empty-icon { font-size: 3rem; margin-bottom: 12px; opacity: 0.6; }
.empty-state h3 { font-size: 1.1rem; margin-bottom: 4px; color: var(--text-secondary); }

/* === Responsive === */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    transform: translateX(-100%);
    box-shadow: none;
  }
  .sidebar.open { transform: translateX(0); box-shadow: var(--shadow-hover); }
  .menu-btn { display: flex; }
  .content { padding: 0 20px 48px; }
  .welcome { padding-top: 32px; }
  .welcome-hero h1 { font-size: 1.5rem; }
  .welcome-stats { gap: 16px; flex-wrap: wrap; }
  .stat-card { padding: 12px 18px; min-width: 80px; }
  .stat-card .stat-num { font-size: 1.3rem; }
  .preview-grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); }
  .chapter-view, .about-view { padding-top: 24px; }
  .chapter-footer { flex-direction: column; align-items: stretch; }
  .search-box { max-width: none; }
  .topbar { padding: 0 16px; gap: 10px; }
  .chapter-indicator { display: none; }
}