/* ============================================================
   BUFFETT LETTERS WIKI — Editorial Heritage Design System
   ============================================================
   Sophisticated, minimalist luxury inspired by high-end 
   publications. Typography-first, refined color palette, 
   generous spacing, and subtle depth effects. */

:root {
  /* Modern Executive Palette: High-Contrast Slate + Pure White + Vibrant Accents */
  --primary-ink: #0f172a; /* Deeper slate for text */
  --secondary-ink: #475569;
  --light-text: #94a3b8;
  --pale-bg: #f8fafc; /* Crisp light gray-blue */
  --cream-bg: #ffffff; /* Pure white */
  --surface-card: #ffffff;
  --line-color: #e2e8f0; /* Softer, cleaner borders */
  --accent-gold: #ca8a04; /* Slightly more vibrant gold */
  --accent-navy: #0f172a; /* Slate 900 for modern feel */
  --accent-blue: #2563eb; /* Modern vibrant blue */
  --accent-green: #10b981; /* Emerald 500 */
  
  /* Glassmorphism & Depth */
  --glass-bg: rgba(255, 255, 255, 0.8);
  --glass-border: rgba(255, 255, 255, 0.3);
  
  /* Typography */
  --font-display: 'Playfair Display', 'Georgia', serif;
  --font-serif: 'Source Serif Pro', 'Georgia', serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  
  /* Spacing & Layout */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 12px;
  --space-lg: 16px;
  --space-xl: 24px;
  --space-2xl: 32px;
  --space-3xl: 48px;
  
  /* Border Radius */
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  /* Shadows: Modern, larger, softer */
  --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);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* Transitions: Fluid & Snappy */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

body.dark {
  --primary-ink: #f1f5f9;
  --secondary-ink: #94a3b8;
  --light-text: #64748b;
  --pale-bg: #0f172a;
  --cream-bg: #020617;
  --surface-card: #1e293b;
  --line-color: #334155;
  --accent-gold: #f59e0b;
  --accent-navy: #38bdf8;
  --accent-green: #34d399;
  
  --glass-bg: rgba(15, 23, 42, 0.8);
  --glass-border: rgba(255, 255, 255, 0.05);
  
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.5);
}

body.dark .sun-icon { display: none; }
body.dark .moon-icon { display: block !important; }

* {
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  min-width: 320px;
  background: var(--pale-bg);
  color: var(--primary-ink);
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--pale-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--line-color);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--light-text);
}

/* ============================================================
   FORM ELEMENTS & BUTTONS */

input,
select,
textarea,
button {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: none;
  padding: 0;
  background: transparent;
}

input,
select,
textarea {
  border: 1px solid var(--line-color);
  border-radius: 4px;
  background: var(--cream-bg);
  padding: var(--space-md);
  transition: all var(--transition-fast);
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--accent-navy);
  box-shadow: 0 0 0 3px rgba(26, 58, 82, 0.1);
}

/* ============================================================
   LAYOUT: APP SHELL */

.app-shell {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 100vh;
  background: var(--cream-bg);
}

/* ============================================================
   HEADER: TOPBAR */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-xl);
  padding: var(--space-md) var(--space-2xl);
  border-bottom: 1px solid var(--line-color);
  background: var(--glass-bg);
  backdrop-filter: blur(12px) saturate(180%);
  position: sticky;
  top: 0;
  z-index: 100;
  height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  min-width: 0;
}

.mark {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2px;
  background: var(--accent-navy);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  flex-shrink: 0;
  transition: transform var(--transition-fast);
}

.mark:hover {
  transform: scale(1.05) rotate(-2deg);
}

.mark-letter {
  color: white;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.brand-text {
  min-width: 0;
}

.brand-main {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.3px;
  color: var(--primary-ink);
}

.brand-status {
  font-size: 10px;
  color: var(--light-text);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-top: 2px;
  font-weight: 600;
}

.toolbar {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
  flex-wrap: wrap;
  justify-content: flex-end;
}
.toolbar-group {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.panel-toggle-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: transparent;
  border: 1px solid transparent;
  color: var(--secondary-ink);
  padding: 0;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-base);
}

.panel-toggle-btn:hover {
  background: var(--pale-bg);
  color: var(--accent-navy);
  border-color: var(--line-color);
  transform: translateY(-1px);
}

.panel-toggle-btn svg {
  display: block;
}

.toolbar-label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--light-text);
  font-weight: 700;
}

.toolbar-select,
.toolbar-input {
  height: 34px;
  padding: 0 var(--space-md);
  font-size: 12px;
  border-radius: var(--radius-sm);
  min-width: 90px;
  border: 1px solid var(--line-color);
  background: var(--cream-bg);
  transition: all var(--transition-base);
}

.toolbar-select:hover,
.toolbar-input:hover {
  border-color: var(--light-text);
}

.toolbar-select:focus,
.toolbar-input:focus {
  border-color: var(--accent-navy);
  box-shadow: 0 0 0 3px rgba(15, 23, 42, 0.1);
}

.year-range {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.year-dash {
  color: var(--light-text);
  font-weight: 300;
}

.support-link {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 0 var(--space-lg);
  height: 36px;
  background: var(--pale-bg);
  border: 1px solid var(--line-color);
  border-radius: var(--radius-sm);
  color: var(--secondary-ink);
  text-decoration: none;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: all var(--transition-base);
}

.support-link:hover {
  background: var(--cream-bg);
  color: var(--accent-gold);
  border-color: var(--accent-gold);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.support-link svg {
  color: var(--accent-gold);
}

.toolbar-input {
  width: 64px;
  text-align: center;
}

/* ============================================================
   MAIN WORKSPACE: 3-COLUMN GRID */

.workspace {
  display: grid;
  grid-template-columns: 280px 1fr 340px;
  gap: 0;
  height: calc(100vh - 72px);
  transition: grid-template-columns var(--transition-slow);
}

.workspace.left-collapsed {
  grid-template-columns: 0px 1fr 340px;
}

.workspace.right-collapsed {
  grid-template-columns: 280px 1fr 0px;
}

.workspace.left-collapsed.right-collapsed {
  grid-template-columns: 0px 1fr 0px;
}

/* ============================================================
   SIDEBAR: ARCHIVE NAVIGATION */

.sidebar-nav {
  display: grid;
  grid-template-rows: auto auto 1fr;
  border-right: 1px solid var(--line-color);
  background: var(--cream-bg);
  overflow: hidden;
  transition: transform var(--transition-slow), opacity var(--transition-slow);
}

.left-collapsed .sidebar-nav {
  transform: translateX(-100%);
  opacity: 0;
  pointer-events: none;
}

/* ============================================================
   SIDEBAR TABS (Modern Pill Style) */

.sidebar-tabs {
  display: flex;
  gap: var(--space-xs);
  padding: var(--space-md);
  border-bottom: 1px solid var(--line-color);
  background: var(--pale-bg);
}

.tab-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 4px;
  border: none;
  background: transparent;
  color: var(--secondary-ink);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  user-select: none;
}

.tab-btn:hover {
  background: rgba(15, 23, 42, 0.04);
  color: var(--accent-navy);
}

.tab-btn:active {
  transform: scale(0.95);
}

.tab-btn.active {
  background: var(--cream-bg);
  color: var(--accent-navy);
  box-shadow: var(--shadow-sm);
}

/* Tab Content Visibility */
.tab-content {
  display: none;
  grid-template-rows: auto auto 1fr;
  overflow: hidden;
}

.tab-content.active {
  display: grid;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding: var(--space-xl);
  border-bottom: 1px solid var(--line-color);
}

.sidebar-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  color: var(--primary-ink);
  letter-spacing: -0.3px;
}

.sidebar-home-btn {
  padding: var(--space-sm) var(--space-md);
  height: 32px;
  border: 1px solid var(--line-color);
  border-radius: 3px;
  font-size: 12px;
  font-weight: 500;
  color: var(--accent-navy);
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.sidebar-home-btn:hover {
  background: var(--pale-bg);
  border-color: var(--accent-navy);
}

/* Category Tabs (Sub-nav) */
.category-tabs {
  display: flex;
  gap: var(--space-xs);
  padding: var(--space-md) var(--space-lg);
  border-bottom: 1px solid var(--line-color);
  background: var(--cream-bg);
  overflow-x: auto;
  scrollbar-width: none; /* Hide scrollbar for clean look */
  -ms-overflow-style: none;
}

.category-tabs::-webkit-scrollbar {
  display: none;
}

.cat-tab {
  padding: 6px 12px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 700;
  color: var(--secondary-ink);
  background: var(--pale-bg);
  border: 1px solid var(--line-color);
  white-space: nowrap;
  transition: all var(--transition-base);
  cursor: pointer;
}

.cat-tab:hover {
  background: var(--line-color);
  color: var(--accent-navy);
}

.cat-tab.active {
  background: var(--accent-navy);
  color: white;
  border-color: var(--accent-navy);
  box-shadow: var(--shadow-sm);
}

.sidebar-search {
  position: relative;
  padding: var(--space-md) var(--space-lg);
}

/* Search Tab Styles */
.sidebar-search-full {
  display: grid;
  gap: var(--space-md);
  padding: var(--space-lg);
}

.search-mode-selector,
.year-filter {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.mode-label,
.year-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--light-text);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.mode-select {
  flex: 1;
  height: 34px;
  padding: 0 var(--space-md);
  font-size: 12px;
  border: 1px solid var(--line-color);
  border-radius: 3px;
  background: var(--cream-bg);
  color: var(--primary-ink);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.mode-select:hover,
.mode-select:focus {
  border-color: var(--accent-navy);
  background: var(--surface-card);
}

.year-filter {
  justify-content: space-between;
}

.year-input {
  width: 50px;
  height: 34px;
  padding: 0 var(--space-sm) !important;
  text-align: center;
  font-size: 12px;
  border: 1px solid var(--line-color);
  border-radius: 3px;
}

.year-sep {
  color: var(--light-text);
  font-size: 12px;
}

.sidebar-search-input {
  width: 100%;
  height: 36px;
  padding: 0 var(--space-md) !important;
  font-size: 13px;
  border: 1px solid var(--line-color);
  border-radius: 3px;
}

.search-btn-sidebar {
  width: 100%;
  padding: var(--space-md);
  height: 36px;
  background: var(--accent-navy);
  color: white;
  border: none;
  border-radius: 3px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.search-btn-sidebar:hover {
  background: #2a5a7a;
  box-shadow: var(--shadow-md);
}

.results-list-sidebar {
  overflow-y: auto;
  padding: var(--space-md);
  display: grid;
  gap: var(--space-md);
  min-height: 0;
}

/* Chat Tab Styles */
.chat-box-sidebar {
  display: grid;
  grid-template-rows: 1fr auto;
  gap: var(--space-md);
  padding: var(--space-lg);
  min-height: 0;
  overflow: hidden;
}

.chat-log-sidebar {
  overflow-y: auto;
  padding: var(--space-md);
  background: rgba(255, 255, 255, 0.5);
  border-radius: 3px;
  border: 1px solid var(--line-color);
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.chat-form-sidebar {
  display: grid;
  gap: var(--space-md);
}

.chat-input-sidebar {
  width: 100%;
  min-height: 60px;
  max-height: 120px;
  resize: vertical;
  border: 1px solid var(--line-color);
  border-radius: 3px;
  padding: var(--space-md) !important;
  font-size: 12px;
  line-height: 1.4;
}

.chat-submit-sidebar {
  width: 100%;
  padding: var(--space-md);
  height: 34px;
  background: var(--accent-green);
  color: white;
  border: none;
  border-radius: 3px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.chat-submit-sidebar:hover {
  background: #2a5e50;
  box-shadow: var(--shadow-md);
}

/* ============================================================
   BOOKMARKS SIDEBAR */

.bookmark-actions {
  display: flex;
  gap: var(--space-sm);
}

.sidebar-action-btn {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line-color);
  border-radius: 3px;
  background: transparent;
  color: var(--light-text);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: 12px;
}

.sidebar-action-btn:hover {
  background: rgba(26, 58, 82, 0.06);
  border-color: var(--accent-navy);
  color: var(--accent-navy);
}

.bookmark-filter {
  width: 100%;
  padding: var(--space-md);
  border: 1px solid var(--line-color);
  border-radius: 3px;
  font-size: 13px;
  background: var(--cream-bg);
  margin-bottom: var(--space-md);
}

.bookmarks-container {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 0;
  overflow: hidden;
  padding: var(--space-md);
}

.bookmarks-list {
  overflow-y: auto;
  display: grid;
  gap: var(--space-md);
}

.bookmark-item {
  padding: var(--space-md);
  background: white;
  border: 1px solid var(--line-color);
  border-radius: 3px;
  display: grid;
  gap: var(--space-sm);
  font-size: 12px;
}

.bookmark-item-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-md);
}

.bookmark-item-title {
  font-weight: 600;
  color: var(--accent-navy);
  flex: 1;
  font-size: 13px;
  cursor: pointer;
}

.bookmark-item-title:hover {
  text-decoration: underline;
}

.bookmark-item-meta-top {
  display: flex;
  gap: var(--space-sm);
  align-items: center;
  flex-wrap: wrap;
  padding: var(--space-sm) var(--space-md) 0;
  font-size: 11px;
}

.collection-badge {
  display: inline-block;
  padding: 3px 8px;
  background: rgba(184, 134, 11, 0.15);
  border: 1px solid rgba(184, 134, 11, 0.3);
  border-radius: 3px;
  color: var(--accent-navy);
  font-weight: 500;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.bookmark-item-tags {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

.tag-badge {
  display: inline-block;
  padding: 2px 6px;
  background: rgba(26, 58, 82, 0.1);
  border: 1px solid rgba(26, 58, 82, 0.2);
  border-radius: 2px;
  color: var(--accent-navy);
  font-size: 10px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.tag-badge:hover {
  background: rgba(26, 58, 82, 0.2);
  border-color: var(--accent-navy);
}

.tag-badge.removable::after {
  content: " ✕";
  margin-left: 3px;
  opacity: 0.6;
}

.tag-badge.removable:hover::after {
  opacity: 1;
}

.bookmark-item-meta {
  display: flex;
  gap: var(--space-md);
  font-size: 11px;
  color: var(--light-text);
}

.bookmark-item-text {
  padding: var(--space-md);
  background: var(--cream-bg);
  border-left: 2px solid var(--accent-gold);
  font-style: italic;
  line-height: 1.5;
  color: var(--dark-text);
}

.bookmark-item-note {
  padding: var(--space-sm) var(--space-md);
  background: var(--pale-bg);
  border-radius: 2px;
  font-size: 12px;
  color: var(--dark-text);
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.bookmark-item-note:hover {
  background: rgba(255, 255, 200, 0.3);
}

.bookmark-item-note-label {
  font-weight: 600;
  font-size: 11px;
  color: var(--light-text);
  text-transform: uppercase;
  flex-shrink: 0;
}

.note-text {
  flex: 1;
}

.note-edit-btn {
  background: none;
  border: none;
  color: var(--light-text);
  font-size: 12px;
  cursor: pointer;
  opacity: 0;
  transition: all var(--transition-fast);
  padding: 2px 4px;
  flex-shrink: 0;
}

.bookmark-item-note:hover .note-edit-btn {
  opacity: 1;
  color: var(--accent-navy);
}

.bookmark-item-note.empty {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  padding: var(--space-md);
  background: rgba(255, 255, 200, 0.15);
  border: 1px dashed var(--line-color);
  border-radius: 2px;
  min-height: 40px;
}

.note-add-btn {
  background: none;
  border: none;
  color: var(--light-text);
  font-size: 12px;
  cursor: pointer;
  font-weight: 500;
  transition: color var(--transition-fast);
  padding: 4px 8px;
}

.bookmark-item-note.empty:hover .note-add-btn {
  color: var(--accent-navy);
}

/* Annotation Edit Mode */
.bookmark-item-note-edit {
  padding: var(--space-md);
  background: var(--pale-bg);
  border-radius: 2px;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.note-edit-textarea {
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--accent-gold);
  border-radius: 2px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 12px;
  line-height: 1.5;
  resize: vertical;
  min-height: 80px;
  max-height: 150px;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1);
  transition: all var(--transition-fast);
}

.note-edit-textarea:focus {
  outline: none;
  border-color: var(--accent-gold);
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1), 0 0 0 2px rgba(184, 134, 11, 0.2);
}

.note-edit-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-md);
  padding-top: var(--space-sm);
  border-top: 1px solid rgba(26, 58, 82, 0.1);
}

.note-char-count {
  font-size: 11px;
  color: var(--light-text);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.note-edit-buttons {
  display: flex;
  gap: var(--space-sm);
}

.note-save-btn,
.note-cancel-btn {
  padding: 4px 12px;
  border: 1px solid var(--line-color);
  border-radius: 2px;
  background: transparent;
  font-size: 11px;
  font-weight: 600;
  color: var(--accent-navy);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.note-save-btn {
  background: rgba(184, 134, 11, 0.1);
  border-color: var(--accent-gold);
  color: var(--accent-gold);
}

.note-save-btn:hover {
  background: rgba(184, 134, 11, 0.2);
  border-color: var(--accent-gold);
}

.note-cancel-btn:hover {
  background: rgba(26, 58, 82, 0.06);
  border-color: var(--accent-navy);
}

.note-preview-btn,
.note-edit-back-btn {
  padding: 6px 12px;
  font-size: 12px;
  font-weight: 500;
  border: 1px solid var(--line-color);
  border-radius: 3px;
  background: rgba(184, 134, 11, 0.05);
  color: var(--accent-navy);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.note-preview-btn:hover,
.note-edit-back-btn:hover {
  background: rgba(184, 134, 11, 0.15);
  border-color: var(--accent-gold);
}

.bookmark-item-note-preview {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  padding: var(--space-md);
  background: rgba(253, 253, 251, 0.5);
  border: 1px solid var(--line-color);
  border-radius: 3px;
  animation: fadeIn var(--transition-normal);
}

.note-preview-content {
  line-height: 1.6;
  font-size: 13px;
  color: var(--primary-ink);
  word-wrap: break-word;
}

.note-preview-content p {
  margin: var(--space-sm) 0;
}

.note-preview-content strong {
  font-weight: 700;
  color: var(--accent-navy);
}

.note-preview-content em {
  font-style: italic;
  color: var(--accent-navy);
}

.note-preview-content code {
  background: rgba(61, 110, 95, 0.1);
  color: var(--accent-green);
  padding: 2px 6px;
  border-radius: 2px;
  font-family: 'Monaco', 'Menlo', monospace;
  font-size: 11px;
}

.note-preview-content pre {
  background: rgba(26, 58, 82, 0.05);
  border: 1px solid var(--line-color);
  border-radius: 3px;
  padding: var(--space-sm);
  overflow-x: auto;
  margin: var(--space-sm) 0;
}

.note-preview-content pre code {
  background: transparent;
  color: var(--primary-ink);
  padding: 0;
  border-radius: 0;
}

.note-preview-content h1,
.note-preview-content h2,
.note-preview-content h3 {
  margin: var(--space-md) 0 var(--space-sm) 0;
  color: var(--accent-navy);
}

.note-preview-content h1 {
  font-size: 16px;
  font-weight: 700;
}

.note-preview-content h2 {
  font-size: 14px;
  font-weight: 700;
}

.note-preview-content h3 {
  font-size: 13px;
  font-weight: 600;
}

.note-preview-content blockquote {
  border-left: 3px solid var(--accent-gold);
  padding-left: var(--space-md);
  margin: var(--space-md) 0;
  color: var(--light-text);
  font-style: italic;
}

.note-preview-content ul,
.note-preview-content ol {
  margin: var(--space-sm) 0 var(--space-sm) var(--space-lg);
  padding-left: var(--space-lg);
}

.note-preview-content li {
  margin: 4px 0;
}

.note-preview-content a {
  color: var(--accent-gold);
  text-decoration: none;
  border-bottom: 1px solid rgba(184, 134, 11, 0.3);
  transition: all var(--transition-fast);
}

.note-preview-content a:hover {
  border-bottom-color: var(--accent-gold);
}

/* ============================================================ */
/* PHASE 6: TAGS, COLLECTIONS & FILTERING */

.collections-panel {
  background: rgba(253, 253, 251, 0.5);
  border-bottom: 1px solid var(--line-color);
  padding: var(--space-md);
  margin-bottom: var(--space-md);
}

.collections-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-sm);
}

.collections-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--light-text);
  margin: 0;
}

.collections-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.collection-item {
  padding: 6px 8px;
  background: transparent;
  border: 1px solid var(--line-color);
  border-radius: 2px;
  font-size: 12px;
  color: var(--dark-text);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.collection-item:hover {
  background: rgba(184, 134, 11, 0.05);
  border-color: var(--accent-gold);
}

.collection-item.active {
  background: rgba(184, 134, 11, 0.1);
  border-color: var(--accent-gold);
  font-weight: 600;
  color: var(--accent-navy);
}

.collection-count {
  font-size: 10px;
  color: var(--light-text);
  background: rgba(26, 58, 82, 0.1);
  padding: 1px 5px;
  border-radius: 2px;
}

.filter-panel {
  background: rgba(253, 253, 251, 0.3);
  border-bottom: 1px solid var(--line-color);
  padding: var(--space-md);
  margin-bottom: var(--space-md);
}

.filter-group {
  margin-bottom: var(--space-md);
}

.filter-label {
  display: block;
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--light-text);
  margin-bottom: 6px;
}

.quick-filters {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
}

.quick-filter {
  padding: 6px 8px;
  font-size: 11px;
  font-weight: 500;
  border: 1px solid var(--line-color);
  border-radius: 2px;
  background: transparent;
  color: var(--light-text);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.quick-filter:hover {
  background: rgba(184, 134, 11, 0.1);
  border-color: var(--accent-gold);
  color: var(--accent-navy);
}

.quick-filter.active {
  background: rgba(184, 134, 11, 0.2);
  border-color: var(--accent-gold);
  color: var(--accent-navy);
  font-weight: 600;
}

.bookmark-filter {
  width: 100%;
  padding: 8px 12px;
  margin-bottom: var(--space-sm);
  font-size: 12px;
  border: 1px solid var(--line-color);
  border-radius: 3px;
  background: white;
  color: var(--dark-text);
  transition: all var(--transition-fast);
}

.bookmark-filter:focus {
  outline: none;
  border-color: var(--accent-gold);
  box-shadow: 0 0 0 2px rgba(184, 134, 11, 0.1);
}

.filter-tags {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
  font-size: 11px;
}

.filter-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 6px;
  background: rgba(61, 110, 95, 0.1);
  border: 1px solid rgba(61, 110, 95, 0.3);
  border-radius: 2px;
  color: var(--accent-green);
  font-weight: 500;
}

.filter-tag-remove {
  background: none;
  border: none;
  color: inherit;
  cursor: pointer;
  font-weight: 700;
  padding: 0;
  margin: 0;
  font-size: 10px;
}

.filter-tag-remove:hover {
  opacity: 0.7;
}

/* Tag badges in bookmark items */
.tag-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 8px;
  background: rgba(26, 58, 82, 0.05);
  border: 1px solid var(--line-color);
  border-radius: 3px;
  font-size: 12px;
  color: var(--accent-navy);
}

.tag-badge .tag-remove {
  background: none;
  border: none;
  color: inherit;
  cursor: pointer;
  padding: 0 4px;
  font-weight: 700;
  margin-left: 6px;
  font-size: 11px;
}

.tag-badge .tag-remove:hover {
  opacity: 0.8;
}

.tag-input-container {
  display: flex;
  gap: 6px;
  align-items: flex-start;
  margin-left: 6px;
}

.tag-input {
  padding: 6px 8px;
  font-size: 12px;
  border: 1px solid var(--line-color);
  border-radius: 3px;
  min-width: 120px;
}

.tag-suggestions {
  position: relative;
  background: white;
  border: 1px solid var(--line-color);
  margin-top: 6px;
  border-radius: 3px;
  box-shadow: var(--shadow-md);
  max-height: 160px;
  overflow: auto;
  z-index: 1500;
}

.tag-suggestion {
  padding: 6px 8px;
  cursor: pointer;
  font-size: 12px;
}

.tag-suggestion:hover {
  background: rgba(26, 58, 82, 0.04);
}

/* Mobile optimization for preview */
@media (max-width: 600px) {
  .bookmark-item-note-preview {
    padding: var(--space-md);
  }

  .note-preview-content {
    font-size: 13px;
  }

  .note-preview-content h1 {
    font-size: 15px;
  }

  .note-preview-content h2 {
    font-size: 13px;
  }

  .note-preview-content h3 {
    font-size: 12px;
  }

  .note-preview-content code {
    font-size: 11px;
    padding: 2px 4px;
  }

  .note-preview-btn,
  .note-edit-back-btn {
    padding: 8px 12px;
    font-size: 13px;
    min-height: 44px;
  }
}

.bookmark-item-actions {
  display: flex;
  gap: var(--space-sm);
  justify-content: flex-end;
}

.bookmark-btn {
  padding: 4px 8px;
  font-size: 11px;
  border: 1px solid var(--line-color);
  border-radius: 2px;
  background: transparent;
  color: var(--light-text);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.bookmark-btn:hover {
  background: rgba(26, 58, 82, 0.06);
  border-color: var(--accent-navy);
  color: var(--accent-navy);
}

.bookmark-btn.delete:hover {
  background: rgba(220, 53, 69, 0.1);
  border-color: #dc3545;
  color: #dc3545;
}

.bookmark-btn.favorite {
  color: var(--light-text);
  font-size: 13px;
}

.bookmark-btn.favorite:hover {
  color: var(--accent-gold);
  border-color: var(--accent-gold);
  background: rgba(184, 134, 11, 0.1);
}

.empty-state {
  padding: var(--space-2xl) var(--space-md);
  text-align: center;
  color: var(--light-text);
  font-size: 13px;
}

.bookmark-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  background: rgba(184, 134, 11, 0.1);
  border-radius: 2px;
  color: var(--accent-gold);
  font-size: 12px;
  cursor: pointer;
  transition: all var(--transition-fast);
  margin-left: var(--space-sm);
}

.bookmark-icon:hover {
  background: rgba(184, 134, 11, 0.2);
  transform: scale(1.1);
}

.bookmark-icon.bookmarked {
  background: rgba(184, 134, 11, 0.3);
}

/* Share Menu Styles */
.share-menu {
  position: absolute;
  bottom: 100%;
  right: 0;
  background: white;
  border: 1px solid var(--line-color);
  border-radius: 4px;
  box-shadow: 0 4px 12px rgba(26, 58, 82, 0.15);
  z-index: 1000;
  animation: slideInUp var(--transition-base) ease-out;
  margin-bottom: var(--space-sm);
  min-width: 240px;
  overflow: hidden;
}

.share-menu-header {
  padding: var(--space-md);
  border-bottom: 1px solid var(--line-color);
  font-weight: 600;
  font-size: 12px;
  color: var(--accent-navy);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.share-menu-buttons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line-color);
  padding: 1px;
}

.share-btn {
  padding: var(--space-md);
  background: white;
  border: none;
  font-size: 12px;
  font-weight: 500;
  color: var(--accent-navy);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.share-btn:hover {
  background: rgba(184, 134, 11, 0.08);
  color: var(--accent-gold);
}

.share-btn:active {
  background: rgba(184, 134, 11, 0.15);
}

.sidebar-filter {
  width: 100%;
  padding-left: var(--space-2xl);
  font-size: 13px;
}

.icon-search {
  position: absolute;
  left: var(--space-lg);
  top: 50%;
  transform: translateY(-50%);
  color: var(--light-text);
  pointer-events: none;
}

.page-list {
  overflow-y: auto;
  padding: 0 var(--space-md) var(--space-lg);
}

.category {
  margin: var(--space-xl) 0 var(--space-md);
  padding: 0 var(--space-md);
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent-gold);
  border-left: 2px solid var(--accent-gold);
  padding-left: var(--space-md);
}

.page-button {
  width: 100%;
  display: flex;
  align-items: center;
  padding: 10px 14px;
  margin: var(--space-xs) 0;
  text-align: left;
  border: 1px solid transparent;
  background: transparent;
  color: var(--primary-ink);
  font-size: 13px;
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  font-weight: 500;
}

.page-button:hover {
  background: var(--cream-bg);
  border-color: var(--line-color);
  transform: translateX(4px);
  color: var(--accent-navy);
  box-shadow: var(--shadow-sm);
}

.page-button.active {
  background: var(--accent-navy);
  color: white;
  font-weight: 600;
  box-shadow: var(--shadow-md);
}

.page-button.active:hover {
  transform: translateX(0);
  border-color: var(--accent-navy);
}

/* ============================================================
   READER PANEL: CENTER */

.reader-panel {
  display: grid;
  grid-template-rows: auto 1fr;
  background: var(--cream-bg);
  border-right: 1px solid var(--line-color);
  overflow: hidden;
  position: relative;
}

.reader-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-lg);
  padding: var(--space-2xl) var(--space-3xl);
  border-bottom: 1px solid var(--line-color);
  background: var(--surface-card);
}

.reader-meta {
  min-width: 0;
}

.page-category {
  display: inline-block;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent-gold);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  padding: 2px 8px;
  background: rgba(202, 138, 4, 0.1);
  border-radius: var(--radius-full);
}

.page-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 36px;
  font-weight: 800;
  line-height: 1.1;
  color: var(--primary-ink);
  letter-spacing: -1px;
  word-break: break-word;
}

.reader-action-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line-color);
  border-radius: var(--radius-sm);
  color: var(--secondary-ink);
  flex-shrink: 0;
  transition: all var(--transition-base);
  background: var(--cream-bg);
}

.reader-action-btn:hover {
  background: var(--pale-bg);
  border-color: var(--accent-navy);
  color: var(--accent-navy);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.markdown-body {
  overflow-y: auto;
  padding: var(--space-3xl) clamp(var(--space-2xl), 10vw, 120px);
  font-family: var(--font-serif);
  font-size: 17px;
  line-height: 1.8;
  color: var(--primary-ink);
  background: var(--cream-bg);
  scrollbar-gutter: stable;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
  font-family: var(--font-display);
  margin: 2em 0 0.8em;
  color: var(--primary-ink);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.5px;
}

.markdown-body h1 {
  font-size: 42px;
  padding-bottom: var(--space-xl);
  border-bottom: 3px solid var(--accent-gold);
}

.markdown-body h2 {
  font-size: 28px;
  color: var(--accent-navy);
}

.markdown-body blockquote {
  margin: var(--space-3xl) 0;
  padding: var(--space-xl) var(--space-2xl);
  border-left: 4px solid var(--accent-gold);
  background: var(--pale-bg);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-style: italic;
  color: var(--secondary-ink);
  font-size: 16px;
  line-height: 1.9;
  box-shadow: inset 2px 0 8px rgba(0, 0, 0, 0.02);
}

.markdown-body blockquote p {
  margin: 0;
}

.markdown-body code {
  padding: 2px 6px;
  border-radius: 3px;
  background: rgba(26, 58, 82, 0.06);
  font-family: 'Monaco', 'Courier New', monospace;
  font-size: 13px;
  color: var(--accent-navy);
}

.markdown-body pre {
  background: rgba(26, 58, 82, 0.04);
  border-left: 4px solid var(--accent-navy);
  padding: var(--space-lg);
  border-radius: 4px;
  overflow-x: auto;
}

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-2xl) 0;
  font-size: 14px;
}

.markdown-body th,
.markdown-body td {
  padding: var(--space-md);
  text-align: left;
  border-bottom: 1px solid var(--line-color);
}

.markdown-body th {
  background: rgba(26, 58, 82, 0.03);
  font-weight: 600;
  color: var(--accent-navy);
}

.wiki-link {
  display: inline-block;
  padding: 0 var(--space-sm);
  border: none;
  background: rgba(26, 58, 82, 0.08);
  color: var(--accent-navy);
  border-radius: 3px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}

.wiki-link::after {
  content: '↗';
  display: inline-block;
  margin-left: 2px;
  font-size: 0.8em;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.wiki-link:hover {
  background: rgba(26, 58, 82, 0.15);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.wiki-link:hover::after {
  opacity: 1;
}

/* ============================================================
   ASSISTANT PANEL: RIGHT */

.assistant-panel {
  display: grid;
  grid-template-rows: auto 1fr auto;
  border-left: 1px solid var(--line-color);
  background: linear-gradient(to bottom, var(--pale-bg) 0%, var(--cream-bg) 100%);
  overflow: hidden;
  transition: transform var(--transition-slow), opacity var(--transition-slow);
}

.right-collapsed .assistant-panel {
  transform: translateX(100%);
  opacity: 0;
  pointer-events: none;
}

.assistant-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding: var(--space-xl);
  border-bottom: 1px solid var(--line-color);
  background: var(--surface-card);
}

.assistant-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -0.3px;
}

.assistant-action-btn {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line-color);
  border-radius: 3px;
  color: var(--light-text);
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.assistant-action-btn:hover {
  background: rgba(26, 58, 82, 0.06);
  border-color: var(--accent-navy);
  color: var(--accent-navy);
}

.search-section {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 0;
  overflow: hidden;
  border-bottom: 1px solid var(--line-color);
}

.search-box {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-md);
  padding: var(--space-lg);
}

.search-input {
  border-radius: 3px;
  font-size: 13px;
  padding: var(--space-md) !important;
}

.search-btn {
  padding: var(--space-md) var(--space-lg);
  height: 36px;
  background: var(--accent-navy);
  color: white;
  border-radius: 3px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: all var(--transition-fast);
  border: 1px solid var(--accent-navy);
}

.search-btn:hover {
  background: #2a5a7a;
  box-shadow: var(--shadow-md);
}

.results-list {
  overflow-y: auto;
  padding: 0 var(--space-lg) var(--space-lg);
  display: grid;
  gap: var(--space-md);
}

.result {
  margin-bottom: 0;
  padding: var(--space-lg);
  border: 1px solid var(--line-color);
  border-radius: var(--radius-md);
  background: var(--surface-card);
  transition: all var(--transition-base);
  animation: slideInUp 400ms cubic-bezier(0.16, 1, 0.3, 1) both;
}

.result:hover {
  border-color: var(--accent-gold);
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.result button {
  display: block;
  padding: 0;
  margin: 0 0 var(--space-xs);
  border: none;
  background: none;
  text-align: left;
  color: var(--accent-navy);
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  word-break: break-word;
  transition: color var(--transition-fast);
}

.result button:hover {
  color: var(--accent-gold);
}

.result p:first-of-type {
  font-size: 11px;
  color: var(--light-text);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0 0 var(--space-md);
}

.result p:last-of-type {
  margin: 0;
  color: var(--secondary-ink);
  font-size: 13px;
  line-height: 1.6;
}

/* Staggered entry for results */
.result:nth-child(1) { animation-delay: 50ms; }
.result:nth-child(2) { animation-delay: 100ms; }
.result:nth-child(3) { animation-delay: 150ms; }
.result:nth-child(4) { animation-delay: 200ms; }
.result:nth-child(5) { animation-delay: 250ms; }

.chat-section {
  display: grid;
  grid-template-rows: auto 1fr;
  min-height: 0;
  overflow: hidden;
}

.chat-form {
  display: grid;
  gap: var(--space-md);
  padding: var(--space-lg);
  border-bottom: 1px solid var(--line-color);
  background: var(--surface-card);
}

.chat-input {
  width: 100%;
  min-height: 80px;
  max-height: 160px;
  resize: vertical;
  border-radius: var(--radius-sm);
  padding: var(--space-md) !important;
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.5;
  border: 1px solid var(--line-color);
  transition: all var(--transition-base);
}

.chat-input:focus {
  border-color: var(--accent-navy);
  box-shadow: 0 0 0 3px rgba(15, 23, 42, 0.1);
}

.chat-submit {
  padding: var(--space-md) var(--space-lg);
  height: 40px;
  background: var(--accent-green);
  color: white;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: all var(--transition-base);
  border: none;
}

.chat-submit:hover {
  background: #059669;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.chat-log {
  overflow-y: auto;
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.message {
  margin-bottom: 0;
  animation: slideInUp 400ms cubic-bezier(0.16, 1, 0.3, 1) both;
}

.message .role {
  display: block;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--light-text);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  padding-left: 2px;
}

.message .bubble {
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  border: 1px solid var(--line-color);
  background: var(--surface-card);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
  line-height: 1.6;
}

.message.user .bubble {
  background: var(--pale-bg);
  border-color: var(--line-color);
  color: var(--primary-ink);
  border-bottom-right-radius: 2px;
}

.message.assistant .bubble {
  border-left: 4px solid var(--accent-navy);
  border-bottom-left-radius: 2px;
}

.message .bubble:hover {
  box-shadow: var(--shadow-md);
}

.citation {
  margin-top: var(--space-lg);
  padding: var(--space-md);
  border-left: 4px solid var(--accent-gold);
  background: var(--pale-bg);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.citation button {
  color: var(--accent-navy);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  cursor: pointer;
  transition: color var(--transition-fast);
}

.citation button:hover {
  color: var(--accent-gold);
}

.citation p {
  margin: var(--space-xs) 0 0;
  font-size: 11px;
  color: var(--light-text);
  line-height: 1.5;
  font-weight: 500;
}

.empty {
  color: var(--light-text);
  font-size: 13px;
  padding: var(--space-lg);
  text-align: center;
  font-style: italic;
}

.loading {
  color: var(--light-text);
  font-style: italic;
  animation: pulse 1.4s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================================
   RESPONSIVE DESIGN */

@media (max-width: 1280px) {
  .workspace {
    grid-template-columns: 240px 1fr 280px;
  }
}

@media (max-width: 1024px) {
  .workspace {
    grid-template-columns: 1fr;
    grid-template-rows: 1fr;
  }

  .sidebar-nav {
    display: none;
  }

  .assistant-panel {
    position: fixed;
    right: 0;
    top: 77px;
    width: 360px;
    height: calc(100vh - 77px);
    z-index: 50;
    border-left: 1px solid var(--line-color);
    border-right: none;
    background: var(--cream-bg);
    box-shadow: -2px 0 12px rgba(15, 20, 25, 0.1);
    transform: translateX(100%);
    transition: transform var(--transition-slow);
  }

  .assistant-panel.visible {
    transform: translateX(0);
  }

  .reader-panel {
    width: 100%;
  }
}

@media (max-width: 768px) {
  .topbar {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-md);
    padding: var(--space-lg);
  }

  .toolbar {
    width: 100%;
    gap: var(--space-lg);
  }

  .workspace {
    height: auto;
  }

  .reader-panel {
    min-height: 60vh;
  }

  .markdown-body {
    padding: var(--space-lg) var(--space-md);
  }

  .markdown-body h1 {
    font-size: 28px;
  }

  .page-title {
    font-size: 24px;
  }

  .assistant-panel {
    width: 100%;
    position: static;
    height: auto;
    max-height: 50vh;
    transform: none;
  }

  .reader-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-lg);
  }
}

/* ============================================================
   MOBILE OPTIMIZATION (≤600px) */

@media (max-width: 600px) {
  /* Viewport & Spacing */
  html {
    font-size: 14px;
  }

  body {
    padding: 0;
    overflow-x: hidden;
  }

  /* Typography Scaling */
  .markdown-body h1 {
    font-size: 24px;
    line-height: 1.3;
    margin-top: var(--space-lg);
    margin-bottom: var(--space-md);
  }

  .markdown-body h2 {
    font-size: 20px;
    line-height: 1.35;
    margin-top: var(--space-lg);
    margin-bottom: var(--space-md);
  }

  .markdown-body h3 {
    font-size: 16px;
    margin-top: var(--space-md);
    margin-bottom: var(--space-sm);
  }

  .page-title {
    font-size: 20px;
  }

  .page-category {
    font-size: 12px;
  }

  body {
    font-size: 14px;
    line-height: 1.5;
  }

  /* Topbar Optimization */
  .topbar {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    height: auto;
    padding: var(--space-md);
    flex-wrap: nowrap;
  }

  .brand {
    font-size: 14px;
    width: 36px;
    height: 36px;
  }

  .toolbar {
    display: flex;
    gap: var(--space-sm);
    width: auto;
  }

  .toolbar button {
    font-size: 11px;
    padding: var(--space-sm) var(--space-md);
  }

  /* Sidebar Optimization */
  .sidebar {
    width: 100%;
    max-height: auto;
    border-right: none;
    border-bottom: 1px solid var(--line-color);
    overflow-y: auto;
    max-height: 200px;
  }

  .sidebar-tabs {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-sm);
    padding: var(--space-md);
  }

  .tab-btn {
    height: 44px;
    padding: var(--space-sm);
    font-size: 12px;
    min-width: 0;
  }

  .tab-btn svg {
    width: 16px;
    height: 16px;
  }

  .page-filter {
    font-size: 13px;
    height: 36px;
    padding: 0 var(--space-md);
  }

  .page-list {
    max-height: 150px;
    font-size: 12px;
  }

  .page-button {
    font-size: 12px;
    padding: var(--space-sm) var(--space-md);
    height: 36px;
  }

  /* Search UI Optimization */
  .sidebar-search-full {
    padding: var(--space-md);
    gap: var(--space-sm);
  }

  .mode-select,
  .year-filter input,
  #searchInputSidebar {
    font-size: 13px;
    height: 40px;
    padding: var(--space-sm) var(--space-md);
  }

  .search-btn-sidebar {
    height: 40px;
    font-size: 12px;
  }

  .year-filter {
    gap: var(--space-sm);
  }

  .year-filter span {
    font-size: 12px;
  }

  /* Chat UI Optimization */
  .chat-box-sidebar {
    padding: var(--space-md);
    gap: var(--space-sm);
  }

  .chat-input-sidebar {
    font-size: 13px;
    min-height: 36px;
    max-height: 80px;
    padding: var(--space-sm) var(--space-md);
  }

  .chat-submit-sidebar {
    height: 40px;
    font-size: 12px;
  }

  #chatLogSidebar {
    max-height: 120px;
    font-size: 12px;
  }

  /* Reader Panel */
  .reader-panel {
    width: 100%;
    padding: var(--space-md);
    min-height: auto;
  }

  .markdown-body {
    padding: 0;
    max-width: 100%;
  }

  .markdown-body p {
    font-size: 14px;
    line-height: 1.6;
    margin-bottom: var(--space-md);
  }

  .markdown-body blockquote {
    padding-left: var(--space-md);
    border-left-width: 2px;
    font-size: 13px;
    margin: var(--space-md) 0;
  }

  .markdown-body code {
    font-size: 12px;
  }

  /* Buttons & Inputs */
  button,
  input,
  textarea,
  select {
    min-height: 44px;
    font-size: 13px;
  }

  input[type="text"],
  input[type="number"],
  textarea {
    font-size: 16px;
  }

  .wiki-link {
    padding: var(--space-sm) var(--space-md);
    font-size: 13px;
    min-height: 44px;
  }

  /* Search Results */
  .result {
    padding: var(--space-md);
    margin-bottom: var(--space-sm);
    font-size: 12px;
  }

  .result button {
    font-size: 13px;
  }

  .result p {
    font-size: 12px;
    margin: var(--space-sm) 0 0 0;
  }

  /* Chat Messages */
  .message {
    margin-bottom: var(--space-md);
    font-size: 12px;
  }

  .message .role {
    font-size: 11px;
  }

  .message .bubble {
    font-size: 13px;
    padding: var(--space-md);
    max-width: 100%;
    word-wrap: break-word;
  }

  .citation {
    margin-top: var(--space-sm);
    padding: var(--space-sm);
    font-size: 11px;
  }

  /* Assistant Panel */
  .assistant-panel {
    width: 100%;
    position: static;
    height: auto;
    max-height: 40vh;
    border-left: none;
    border-top: 1px solid var(--line-color);
    box-shadow: none;
  }

  #chatForm {
    padding: var(--space-md);
    gap: var(--space-sm);
  }

  #chatInput {
    font-size: 16px;
    height: 40px;
    min-height: 40px;
  }

  .chat-submit {
    height: 40px;
    padding: var(--space-sm) var(--space-md);
    font-size: 12px;
  }

  #chatLog {
    max-height: 30vh;
    font-size: 12px;
  }

  /* Status Line */
  .status-line {
    font-size: 11px;
    padding: var(--space-sm) var(--space-md);
    height: 32px;
  }

  /* Hide Unnecessary Elements on Very Small Screens */
  .tab-btn span {
    display: none;
  }

  .tab-btn {
    flex-direction: column;
    padding: var(--space-md);
  }

  /* Safe Area Support for Notch */
  @supports (padding: max(0px)) {
    .topbar {
      padding-left: max(var(--space-md), env(safe-area-inset-left));
      padding-right: max(var(--space-md), env(safe-area-inset-right));
    }
    .sidebar {
      padding-left: max(var(--space-md), env(safe-area-inset-left));
      padding-right: max(var(--space-md), env(safe-area-inset-right));
    }
  }

  /* Reduce Motion Support */
  @media (prefers-reduced-motion: reduce) {
    * {
      animation: none !important;
      transition: none !important;
    }
  }

  /* Toast Notifications Mobile */
  .toast-container {
    top: auto;
    bottom: var(--space-lg);
    left: var(--space-md);
    right: var(--space-md);
  }

  .toast {
    min-width: 100%;
    max-width: none;
  }

  /* Annotation Editing Mobile */
  .note-edit-textarea {
    font-size: 14px;
    min-height: 100px;
    max-height: 200px;
  }

  .note-edit-controls {
    flex-direction: column;
    align-items: flex-start;
  }

  .note-edit-buttons {
    width: 100%;
    gap: var(--space-sm);
  }

  .note-save-btn,
  .note-cancel-btn {
    flex: 1;
    padding: 12px var(--space-md);
    min-height: 44px;
    font-size: 12px;
  }

  /* Share Menu Mobile Optimization */
  .share-menu {
    position: fixed;
    bottom: auto;
    top: 50%;
    left: 50%;
    right: auto;
    transform: translate(-50%, -50%);
    min-width: 280px;
    z-index: 1001;
  }

  .share-menu-buttons {
    grid-template-columns: 1fr 1fr;
    max-height: 200px;
  }

  .share-btn {
    padding: var(--space-lg);
    font-size: 13px;
    min-height: 44px;
  }

  /* Touch Device Optimizations */
  @media (hover: none) and (pointer: coarse) {
    button {
      padding: var(--space-md) var(--space-lg);
      min-height: 44px;
    }

    a {
      padding: var(--space-sm);
      display: inline-block;
    }

    input,
    textarea {
      padding: var(--space-md);
    }
  }
}

/* ============================================================
   ACCESSIBILITY & FOCUS STATES */

button:focus,
input:focus,
textarea:focus,
select:focus {
  outline: 2px solid var(--accent-gold);
  outline-offset: 2px;
}

/* Remove outline for mouse users, keep for keyboard users */
button:focus:not(:focus-visible),
input:focus:not(:focus-visible),
textarea:focus:not(:focus-visible),
select:focus:not(:focus-visible) {
  outline: none;
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
  button {
    -webkit-tap-highlight-color: rgba(184, 134, 11, 0.2);
  }

  input,
  textarea {
    font-size: 16px;
  }
}

/* ============================================================
   SCROLLBAR STYLING */

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(26, 58, 82, 0.3);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(26, 58, 82, 0.5);
}

/* ============================================================
   TOAST NOTIFICATIONS */

.toast-container {
  position: fixed;
  top: var(--space-lg);
  right: var(--space-lg);
  z-index: 2000;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.toast {
  background: white;
  border: 1px solid var(--line-color);
  border-radius: 4px;
  padding: var(--space-md) var(--space-lg);
  box-shadow: 0 4px 12px rgba(26, 58, 82, 0.15);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  pointer-events: auto;
  min-width: 280px;
  max-width: 400px;
  opacity: 0;
  transform: translateY(-20px);
  transition: all var(--transition-base) ease-out;
}

.toast.toast-show {
  opacity: 1;
  transform: translateY(0);
}

.toast-content {
  flex: 1;
  font-size: 13px;
  color: var(--dark-text);
  font-weight: 500;
}

.toast-success {
  border-left: 3px solid #28a745;
}

.toast-info {
  border-left: 3px solid var(--accent-gold);
}

.toast-error {
  border-left: 3px solid #dc3545;
}

.toast-close {
  background: none;
  border: none;
  color: var(--light-text);
  cursor: pointer;
  font-size: 16px;
  padding: 0;
  transition: color var(--transition-fast);
}

.toast-close:hover {
  color: var(--accent-navy);
}

.toast-action {
  background: var(--accent-navy);
  color: white;
  border: none;
  padding: 4px 12px;
  border-radius: 2px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-fast);
  white-space: nowrap;
}

.toast-action:hover {
  background: rgba(26, 58, 82, 0.85);
}

/* ============================================================
   LOADING SPINNER */

.loading-spinner {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-2xl) var(--space-lg);
}

.spinner-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-gold);
  animation: pulse var(--transition-base) ease-in-out infinite;
}

.spinner-dot:nth-child(2) {
  animation-delay: 0.1s;
}

.spinner-dot:nth-child(3) {
  animation-delay: 0.2s;
}

@keyframes pulse {
  0%, 100% {
    opacity: 0.4;
    transform: scale(0.8);
  }
  50% {
    opacity: 1;
    transform: scale(1);
  }
}



/* Phase 6 Mobile Optimizations */
@media (max-width: 600px) {
  .quick-filters {
    grid-template-columns: repeat(2, 1fr);
  }

  .filter-panel {
    padding: var(--space-sm);
  }

  .filter-group {
    margin-bottom: var(--space-sm);
  }

  .quick-filter {
    font-size: 10px;
    padding: 5px 6px;
  }

  .collections-panel {
    max-height: 150px;
    overflow-y: auto;
  }

  .collection-item {
    font-size: 11px;
    padding: 5px 6px;
  }

  .tag-badge {
    font-size: 9px;
    padding: 2px 4px;
  }

  .collection-badge {
    font-size: 9px;
    padding: 2px 6px;
  }

  .bookmark-item-actions {
    gap: 2px;
  }

  .bookmark-btn {
    padding: 2px 6px;
    font-size: 10px;
  }
}