:root {
  --bg-page: #faf6f1;
  --bg-card: #ffffff;
  --bg-sidebar: #f5f0ea;
  --bg-callout-guideline: #e8f0e8;
  --bg-callout-logic: #fff8e1;
  --bg-callout-trap: #fce8e8;
  --bg-highlight-yellow: rgba(255, 235, 59, 0.35);
  --bg-highlight-green: rgba(129, 199, 132, 0.35);
  --bg-highlight-blue: rgba(100, 181, 246, 0.35);
  --bg-highlight-pink: rgba(244, 143, 177, 0.35);
  --bg-collapsible: #f9f5ef;
  --text-primary: #3d3530;
  --text-secondary: #6b5e54;
  --text-muted: #9a8d82;
  --text-link: #8b6914;
  --border: #e6ddd4;
  --border-strong: #d4c8bc;
  --accent: #c4952a;
  --accent-light: #f0e2c0;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans TC", sans-serif;
  --radius: 8px;
  --sidebar-width: 280px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: var(--font-sans);
  background: var(--bg-page);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 15px;
}

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

.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  padding: 1.5rem 0;
  position: fixed;
  top: 0;
  left: 0;
  height: 100vh;
  overflow-y: auto;
  z-index: 10;
  transition: transform 0.3s ease;
}

.sidebar-header {
  padding: 0 1.25rem 1rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.75rem;
}

.sidebar-header h1 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
}

.sidebar-header p {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.nav-section {
  padding: 0.25rem 0;
}

.nav-specialty {
  display: flex;
  align-items: center;
  padding: 0.5rem 1.25rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background 0.15s;
}

.nav-specialty:hover {
  background: rgba(0,0,0,0.04);
}

.nav-specialty.active {
  color: var(--accent);
  background: var(--accent-light);
}

.nav-specialty .arrow {
  margin-right: 0.5rem;
  font-size: 0.7rem;
  transition: transform 0.2s;
}

.nav-specialty.expanded .arrow {
  transform: rotate(90deg);
}

.nav-diseases {
  display: none;
  padding-left: 1rem;
}

.nav-diseases.show {
  display: block;
}

.nav-disease {
  display: block;
  padding: 0.35rem 1.25rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  text-decoration: none;
  cursor: pointer;
  transition: color 0.15s, background 0.15s;
}

.nav-disease:hover {
  color: var(--text-primary);
  background: rgba(0,0,0,0.03);
}

.nav-disease.active {
  color: var(--accent);
  font-weight: 500;
}

/* Main content */
.main {
  flex: 1;
  margin-left: var(--sidebar-width);
  max-width: 800px;
  padding: 2rem 3rem;
  position: relative;
}

/* Right-side annotation panel */
.annotation-panel {
  position: fixed;
  right: 0;
  top: 0;
  width: 260px;
  height: 100vh;
  overflow-y: auto;
  padding: 1rem 0.75rem;
  background: var(--bg-page);
  border-left: 1px solid var(--border);
  z-index: 5;
}

.annotation-panel h3 {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
}

.ann-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.6rem;
  margin-bottom: 0.5rem;
  font-size: 0.78rem;
  cursor: pointer;
  transition: border-color 0.15s;
}

.ann-card:hover {
  border-color: var(--accent);
}

.ann-card .ann-quote {
  color: var(--text-muted);
  font-style: italic;
  margin-bottom: 0.3rem;
  border-left: 2px solid var(--accent-light);
  padding-left: 0.4rem;
  max-height: 2.4em;
  overflow: hidden;
}

.ann-card .ann-body {
  color: var(--text-primary);
  line-height: 1.5;
}

.ann-card .ann-meta {
  color: var(--text-muted);
  font-size: 0.7rem;
  margin-top: 0.3rem;
}

.ann-card .ann-delete {
  float: right;
  border: none;
  background: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.75rem;
  padding: 0;
}

.ann-card .ann-delete:hover {
  color: #f44336;
}

@keyframes ann-flash-anim {
  0%, 100% { background: transparent; }
  30% { background: var(--bg-highlight-yellow); }
}

.ann-flash {
  animation: ann-flash-anim 1.5s ease;
  border-radius: 3px;
}

/* Username prompt overlay */
.user-prompt-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
}

.user-prompt-box {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 2rem;
  width: 320px;
  text-align: center;
  box-shadow: 0 4px 20px rgba(0,0,0,0.12);
}

.user-prompt-box h2 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.user-prompt-box p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.user-prompt-box input {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.9rem;
  margin-bottom: 0.75rem;
  font-family: var(--font-sans);
}

.user-prompt-box button {
  padding: 0.5rem 1.5rem;
  border: none;
  border-radius: 4px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  font-size: 0.9rem;
  font-family: var(--font-sans);
}

/* Table of Contents */
.note-toc {
  position: sticky;
  top: 0;
  z-index: 8;
  background: var(--bg-page);
  border-bottom: 1px solid var(--border);
  margin: 0 -3rem;
  padding: 0.5rem 3rem;
}

.toc-sections {
  display: flex;
  gap: 0.2rem;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.toc-sections::-webkit-scrollbar { display: none; }

.toc-link {
  flex-shrink: 0;
  padding: 0.3rem 0.6rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: 4px;
  white-space: nowrap;
  transition: all 0.15s;
  text-decoration: none;
}

.toc-link:hover {
  color: var(--text-primary);
  background: rgba(0,0,0,0.04);
}

.toc-link.active {
  color: var(--accent);
  background: var(--accent-light);
  font-weight: 500;
}

.toc-sub {
  display: flex;
  gap: 0.15rem;
  overflow-x: auto;
  margin-top: 0.3rem;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.toc-sub::-webkit-scrollbar { display: none; }

.toc-sub:empty {
  display: none;
  margin-top: 0;
}

.toc-sublink {
  flex-shrink: 0;
  padding: 0.2rem 0.5rem;
  font-size: 0.7rem;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: 3px;
  white-space: nowrap;
  transition: all 0.15s;
  text-decoration: none;
}

.toc-sublink:hover {
  color: var(--text-primary);
  background: rgba(0,0,0,0.04);
}

/* Note content */
.note-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.note-header h1 {
  font-size: 1.75rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.note-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.note-meta span {
  margin-right: 1rem;
}

.note-section {
  margin-bottom: 2rem;
}

.note-section h2 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--accent-light);
  margin-bottom: 0.75rem;
}

.note-section h3 {
  font-size: 1rem;
  font-weight: 500;
  margin: 1rem 0 0.4rem;
}

/* Callouts */
.callout {
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  margin: 0.75rem 0;
  font-size: 0.9rem;
  line-height: 1.6;
}

.callout-guideline {
  background: var(--bg-callout-guideline);
  border-left: 3px solid #4caf50;
}

.callout-logic {
  background: var(--bg-callout-logic);
  border-left: 3px solid #ffc107;
}

.callout-trap {
  background: var(--bg-callout-trap);
  border-left: 3px solid #f44336;
}

.callout .callout-icon {
  margin-right: 0.4rem;
}

/* Collapsible */
details.collapsible {
  background: var(--bg-collapsible);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: 0.75rem 0;
}

details.collapsible summary {
  padding: 0.6rem 1rem;
  cursor: pointer;
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

details.collapsible .content {
  padding: 0 1rem 0.75rem;
  font-size: 0.9rem;
}

/* Tables */
.note-table {
  width: 100%;
  border-collapse: collapse;
  margin: 0.75rem 0;
  font-size: 0.85rem;
}

.note-table th {
  background: var(--bg-sidebar);
  font-weight: 500;
  text-align: left;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
}

.note-table td {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
}

/* Image upload */
.img-dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 0.75rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  cursor: pointer;
  margin-top: 0.75rem;
  transition: border-color 0.2s, background 0.2s;
}

.img-dropzone:hover {
  border-color: var(--accent);
  color: var(--text-secondary);
}

.img-dropzone.dragover {
  border-color: var(--accent);
  background: var(--accent-light);
  color: var(--text-primary);
}

.img-dropzone.uploading {
  opacity: 0.6;
  pointer-events: none;
}

.img-block {
  background: var(--bg-collapsible);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin: 0.75rem 0;
}

.img-block summary {
  padding: 0.6rem 1rem;
  cursor: pointer;
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.img-content {
  padding: 0 1rem 0.75rem;
}

.img-content img {
  max-width: 100%;
  border-radius: 4px;
  display: block;
}

.img-actions {
  margin-top: 0.5rem;
  text-align: right;
}

.img-delete-btn {
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-muted);
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}

.img-delete-btn:hover {
  color: #f44336;
  border-color: #f44336;
}

/* Cross-links */
.related-notes {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.related-notes h3 {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.related-link {
  display: inline-block;
  padding: 0.3rem 0.75rem;
  margin: 0.25rem 0.25rem 0.25rem 0;
  background: var(--accent-light);
  color: var(--text-link);
  border-radius: var(--radius);
  font-size: 0.8rem;
  text-decoration: none;
  transition: background 0.15s;
}

.related-link:hover {
  background: #e8d5a8;
}

/* Highlight colors for user annotations */
.highlight-yellow { background: var(--bg-highlight-yellow); }
.highlight-green { background: var(--bg-highlight-green); }
.highlight-blue { background: var(--bg-highlight-blue); }
.highlight-pink { background: var(--bg-highlight-pink); }

/* Margin notes / annotations */
.margin-note {
  position: absolute;
  right: -220px;
  width: 200px;
  padding: 0.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.75rem;
  color: var(--text-secondary);
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}

/* Source citations */
.source-tag {
  font-size: 0.7rem;
  color: var(--text-muted);
  background: var(--bg-sidebar);
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
  margin-left: 0.3rem;
  vertical-align: super;
}

/* Welcome page */
.welcome {
  text-align: center;
  padding: 4rem 2rem;
}

.welcome h1 {
  font-size: 2rem;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.welcome p {
  color: var(--text-muted);
  font-size: 1rem;
}

.specialty-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-top: 2rem;
  text-align: left;
}

.specialty-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  cursor: pointer;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.specialty-card:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.specialty-card h3 {
  font-size: 0.95rem;
  font-weight: 500;
  margin-bottom: 0.25rem;
}

.specialty-card .count {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Mobile menu */
.menu-toggle {
  display: none;
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 20;
  width: 40px;
  height: 40px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 1.2rem;
  line-height: 40px;
  text-align: center;
}

@media (max-width: 1200px) {
  .annotation-panel { display: none; }
}

@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .main {
    margin-left: 0;
    padding: 1.5rem 1.25rem;
    padding-top: 4rem;
  }
  .menu-toggle {
    display: block;
  }
  .annotation-panel { display: none; }
  .note-toc {
    margin: 0 -1.25rem;
    padding: 0.5rem 1.25rem;
  }
}