/* ==========================================================================
   Q108 Notebook — Glassmorphism Styling & Design System
   ========================================================================== */

:root {
  /* ── Q108 Global Design System Tokens ── */
  --q108-font-display: 'Outfit', sans-serif;
  --q108-font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --q108-font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --q108-black: #06080d;
  --q108-surface-0: #090b12;
  --q108-surface-1: #0b0f19;
  --q108-surface-2: #111827;
  --q108-surface-3: #1e293b;
  --q108-border: rgba(255, 255, 255, 0.10);
  --q108-border-hover: rgba(255, 255, 255, 0.18);

  --q108-text-primary: #f8fafc;
  --q108-text-secondary: #94a3b8;
  --q108-text-muted: #64748b;
  --q108-text-dim: #475569;

  /* ── Q108 Notebook Accent (Purple) ── */
  --q108-accent: #a855f7;
  --q108-accent-glow: 0 0 30px rgba(168, 85, 247, 0.35);

  --bg-dark: #06080d;
  --bg-card: rgba(11, 15, 25, 0.85);
  --bg-card-hover: rgba(26, 33, 56, 0.9);
  --glass-border: rgba(255, 255, 255, 0.10);
  --glass-border-cyan: rgba(168, 85, 247, 0.35);
  --glass-shadow: 0 12px 40px 0 rgba(0, 0, 0, 0.6);
  
  --primary: #a855f7;
  --primary-hover: #9333ea;
  --accent: #a855f7;
  --accent-indigo: #818cf8;
  --accent-gold: #fbbf24;
  --accent-glow: rgba(168, 85, 247, 0.35);
  --peacock-glow: 0 12px 36px rgba(168, 85, 247, 0.35), 0 0 25px rgba(168, 85, 247, 0.25);
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --sidebar-width: 320px;
  --toolbar-height: 64px;
  --drawer-height: 140px;
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  user-select: none;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  height: 100vh;
  width: 100vw;
  overflow: hidden;
  display: flex;
}

/* App Container Layout */
.app-container {
  display: flex;
  width: 100%;
  height: 100%;
  position: relative;
  background: radial-gradient(circle at 50% 30%, #171536 0%, #080c18 55%, #04050a 100%);
}

/* ==========================================================================
   Sidebar Styling
   ========================================================================== */
.sidebar {
  width: var(--sidebar-width);
  height: 100%;
  background: rgba(11, 15, 25, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-right: 1px solid var(--glass-border);
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-normal), width var(--transition-normal);
  z-index: 100;
  box-shadow: var(--glass-shadow);
}

.sidebar.collapsed {
  transform: translateX(-100%);
  position: absolute;
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-logo-img {
  height: 38px;
  width: auto;
  border-radius: 8px;
  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.5));
}

.logo-book-icon {
  font-size: 1.2rem;
  background: linear-gradient(135deg, #ffffff 0%, #cbd5e1 50%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.5));
}

.logo-ai2-text {
  font-family: 'Outfit', 'Inter', sans-serif;
  font-weight: 900;
  font-size: 1.25rem;
  letter-spacing: -0.04em;
  background: linear-gradient(180deg, #ffffff 0%, #e2e8f0 40%, #94a3b8 75%, #475569 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.7));
}

.logo-ai2-text sup {
  font-size: 0.75rem;
  top: -0.45em;
  font-weight: 900;
  background: linear-gradient(180deg, #38bdf8 0%, #818cf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-title {
  font-family: 'Outfit', sans-serif;
  font-size: 1.12rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #fff;
}

.sub-badge {
  font-size: 0.68rem;
  color: #38bdf8;
  background: rgba(56, 189, 248, 0.12);
  padding: 2px 8px;
  border-radius: 20px;
  border: 1px solid rgba(56, 189, 248, 0.25);
  font-weight: 600;
  white-space: nowrap;
}

/* Sidebar Actions */
.sidebar-actions {
  padding: 14px 20px 0 20px;
}

.btn-upload {
  width: 100%;
  padding: 10px 16px;
  background: linear-gradient(135deg, var(--primary), #4338ca);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 0.86rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all var(--transition-fast);
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.3);
}

.btn-upload:hover {
  background: linear-gradient(135deg, #4f46e5, #3730a3);
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(99, 102, 241, 0.45);
}

/* Search Box */
.search-box {
  position: relative;
  margin: 16px 20px 10px 20px;
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-dim);
  font-size: 0.9rem;
}

.search-box input {
  width: 100%;
  padding: 10px 36px 10px 38px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  font-size: 0.88rem;
  transition: all var(--transition-fast);
}

.search-box input:focus {
  outline: none;
  border-color: var(--primary);
  background: rgba(255, 255, 255, 0.07);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.clear-btn {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
}

.clear-btn:hover {
  color: #fff;
}

/* Category Filter Pills */
.category-pills {
  display: flex;
  gap: 6px;
  padding: 6px 20px 14px 20px;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.pill {
  white-space: nowrap;
  padding: 5px 12px;
  border-radius: 20px;
  font-size: 0.76rem;
  font-weight: 500;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.pill:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

.pill.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.35);
}

/* File List */
.file-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px 14px 20px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.file-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.file-item:hover {
  background: var(--bg-card-hover);
  border-color: var(--glass-border);
  transform: translateX(3px);
}

.file-item.active {
  background: rgba(99, 102, 241, 0.15);
  border-color: rgba(99, 102, 241, 0.5);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.file-icon {
  font-size: 1.4rem;
  color: #ef4444;
  flex-shrink: 0;
}

.file-info {
  flex: 1;
  min-width: 0;
}

.file-title {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-main);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-sub {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 3px;
  font-size: 0.73rem;
  color: var(--text-muted);
}

.file-tag {
  background: rgba(255, 255, 255, 0.06);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.68rem;
}

/* Loading & Empty States */
.loading-spinner {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 40px 20px;
  color: var(--text-muted);
  font-size: 0.88rem;
}

.loading-spinner i {
  font-size: 1.8rem;
  color: var(--primary);
}

/* ==========================================================================
   Workspace & Toolbar
   ========================================================================== */
.workspace {
  flex: 1;
  height: 100%;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.toolbar {
  height: var(--toolbar-height);
  background: rgba(11, 15, 25, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px;
  z-index: 50;
  gap: 8px;
  max-width: 100vw;
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: none;
}

.toolbar::-webkit-scrollbar {
  display: none;
}

.toolbar-left, .toolbar-center, .toolbar-right {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.current-doc-info {
  display: flex;
  flex-direction: column;
  max-width: clamp(100px, 18vw, 260px);
}

#doc-title {
  font-family: 'Outfit', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  color: #fff;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.doc-meta {
  font-size: 0.73rem;
  color: var(--text-muted);
}

/* Buttons & Inputs */
.btn-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: 0.9rem;
}

.btn-icon:hover {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.2);
}

.btn-icon.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  box-shadow: 0 0 12px rgba(56, 189, 248, 0.4);
}

/* Mouse Scroll Mode Toggle Button Styling */
#scroll-mode-btn {
  width: auto;
  min-width: 36px;
  padding: 0 10px;
  gap: 6px;
  position: relative;
  transition: all 0.25s ease;
}

#scroll-mode-btn .btn-scroll-label {
  font-size: 0.74rem;
  font-weight: 700;
  white-space: nowrap;
  letter-spacing: 0.2px;
}

#scroll-mode-btn.active {
  background: linear-gradient(135deg, #0284c7, #38bdf8);
  border-color: #38bdf8;
  color: #ffffff;
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.45);
}

.divider {
  width: 1px;
  height: 24px;
  background: var(--glass-border);
  margin: 0 4px;
}

.tool-group {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(255, 255, 255, 0.03);
  padding: 4px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--glass-border);
}

#zoom-level {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  min-width: 44px;
  text-align: center;
}

.pagination-controls {
  display: flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.04);
  padding: 4px 8px;
  border-radius: var(--radius-md);
  border: 1px solid var(--glass-border);
}

.page-input-wrapper {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

.page-input-wrapper input {
  width: 44px;
  padding: 4px 6px;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--glass-border);
  border-radius: 4px;
  color: #fff;
  text-align: center;
  font-size: 0.85rem;
  font-weight: 600;
}

.page-input-wrapper input:focus {
  outline: none;
  border-color: var(--primary);
}

/* ==========================================================================
   Viewport & Flipbook Rendering
   ========================================================================== */
.viewport {
  flex: 1;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 20px;
}

.flipbook-wrapper {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s ease-out;
}

.st-page-flip {
  margin: 0 auto;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6);
  border-radius: 4px;
}

.st-page-flip .page {
  background-color: #ffffff;
  background-size: contain;
  background-position: center;
  background-repeat: no-repeat;
  box-shadow: inset 0 0 20px rgba(0, 0, 0, 0.1);
  overflow: hidden;
}

.st-page-flip .page canvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* Page Shadow Effect */
.st-page-flip .page.--left {
  border-right: 1px solid rgba(0, 0, 0, 0.1);
}

.st-page-flip .page.--right {
  border-left: 1px solid rgba(0, 0, 0, 0.1);
}

/* Page Placeholder Loader Skeleton */
.page-placeholder {
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at 50% 50%, #f8fafc 0%, #e2e8f0 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  color: #64748b;
  font-size: 0.85rem;
  font-weight: 500;
}

.page-placeholder i {
  font-size: 1.5rem;
  color: var(--primary);
}

/* ==========================================================================
   Loader Overlay & Animations
   ========================================================================== */
.pdf-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(9, 13, 22, 0.92);
  backdrop-filter: blur(12px);
  z-index: 80;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.3s ease;
}

.pdf-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.loader-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  max-width: 320px;
  text-align: center;
}

.loader-content h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 1.1rem;
  font-weight: 600;
  color: #fff;
}

.loader-content p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.loader-logo-img {
  width: 90px;
  height: 90px;
  border-radius: 20px;
  object-fit: cover;
  box-shadow: 0 8px 30px rgba(56, 189, 248, 0.4), 0 0 15px rgba(99, 102, 241, 0.3);
  animation: logoPulse 2s infinite ease-in-out;
}

@keyframes logoPulse {
  0% {
    transform: scale(1);
    box-shadow: 0 8px 30px rgba(56, 189, 248, 0.4), 0 0 15px rgba(99, 102, 241, 0.3);
  }
  50% {
    transform: scale(1.06);
    box-shadow: 0 12px 40px rgba(56, 189, 248, 0.6), 0 0 25px rgba(99, 102, 241, 0.5);
  }
  100% {
    transform: scale(1);
    box-shadow: 0 8px 30px rgba(56, 189, 248, 0.4), 0 0 15px rgba(99, 102, 241, 0.3);
  }
}

.book-loader .page {
  width: 24px;
  height: 36px;
  background: var(--primary);
  position: absolute;
  top: 0;
  right: 0;
  border-radius: 0 4px 4px 0;
  transform-origin: left center;
  animation: flip 1.2s infinite ease-in-out;
}

.book-loader .page:nth-child(2) {
  animation-delay: 0.3s;
}

.book-loader .page:nth-child(3) {
  animation-delay: 0.6s;
}

@keyframes flip {
  0% { transform: rotateY(0deg); opacity: 1; }
  100% { transform: rotateY(-180deg); opacity: 0; }
}

/* Progress Bar */
.progress-bar-container {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  overflow: hidden;
}

.progress-bar {
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width 0.2s ease;
}

/* ==========================================================================
   Thumbnail Drawer
   ========================================================================== */
.thumbnail-drawer {
  height: var(--drawer-height);
  background: rgba(11, 15, 25, 0.9);
  backdrop-filter: blur(16px);
  border-top: 1px solid var(--glass-border);
  display: flex;
  flex-direction: column;
  position: relative;
  z-index: 60;
  transition: transform var(--transition-normal);
}

.thumbnail-drawer.hidden {
  transform: translateY(100%);
  position: absolute;
  bottom: 0;
  width: 100%;
}

.drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 16px;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
  border-bottom: 1px solid var(--glass-border);
}

.close-drawer-btn {
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
}

.close-drawer-btn:hover {
  color: #fff;
}

.thumbnail-strip {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 16px;
  overflow-x: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--primary) transparent;
}

.thumb-item {
  height: 85px;
  aspect-ratio: 1 / 1.414;
  background: #fff;
  border-radius: 4px;
  overflow: hidden;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
  flex-shrink: 0;
}

.thumb-item:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
}

.thumb-item.active {
  border-color: var(--primary);
  box-shadow: 0 0 12px var(--primary);
}

.thumb-item canvas {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.thumb-num {
  position: absolute;
  bottom: 2px;
  right: 2px;
  background: rgba(0, 0, 0, 0.75);
  color: #fff;
  font-size: 0.65rem;
  padding: 1px 4px;
  border-radius: 3px;
}

/* Utilities */
.hidden {
  display: none !important;
}

/* Scrollbar Customization */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.3);
}

/* ==========================================================================
   Omni-Search Trigger & Spotlight Modal Styles
   ========================================================================== */
.btn-omni-trigger {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  padding: 6px 14px;
  border-radius: 20px;
  color: var(--text-muted);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  margin-right: 12px;
}

.btn-omni-trigger:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  color: #fff;
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.2);
}

.omni-bolt-icon {
  color: var(--accent);
  font-size: 0.9rem;
}

.btn-omni-trigger kbd {
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--glass-border);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 0.68rem;
  font-family: inherit;
  color: var(--accent);
}

/* Modal Overlay */
.omni-modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(5, 8, 15, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 2000;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 80px;
  transition: opacity 0.2s ease;
}

.omni-modal-dialog {
  width: 100%;
  max-width: 720px;
  max-height: 80vh;
  background: rgba(15, 23, 42, 0.95);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.8), 0 0 30px rgba(99, 102, 241, 0.2);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  animation: modalSlideDown 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalSlideDown {
  from { opacity: 0; transform: translateY(-20px) scale(0.98); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.omni-modal-header {
  padding: 18px 20px 14px 20px;
  border-bottom: 1px solid var(--glass-border);
}

.omni-search-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  position: relative;
}

.omni-modal-icon {
  font-size: 1.2rem;
  color: var(--accent);
}

.omni-search-bar input {
  flex: 1;
  background: transparent;
  border: none;
  color: #fff;
  font-size: 1.1rem;
  font-family: 'Outfit', sans-serif;
  font-weight: 500;
}

.omni-search-bar input:focus {
  outline: none;
}

.omni-esc-badge {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--glass-border);
  border-radius: 4px;
  padding: 2px 6px;
  font-size: 0.7rem;
  color: var(--text-muted);
}

.btn-icon-sm {
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 1.1rem;
  cursor: pointer;
}

.btn-icon-sm:hover {
  color: #fff;
}

.omni-status-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 10px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.omni-index-badge {
  color: var(--accent);
  background: rgba(56, 189, 248, 0.12);
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 0.72rem;
  border: 1px solid rgba(56, 189, 248, 0.25);
}

/* Modal Body & Results */
.omni-modal-body {
  flex: 1;
  overflow-y: auto;
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.omni-empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 50px 20px;
  color: var(--text-muted);
  font-size: 0.9rem;
  text-align: center;
}

.omni-doc-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.omni-group-header {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
  padding: 4px 6px;
}

.omni-group-header i {
  color: #ef4444;
}

.omni-group-title {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.omni-group-badge {
  font-size: 0.72rem;
  color: var(--accent);
  background: rgba(56, 189, 248, 0.12);
  padding: 1px 8px;
  border-radius: 10px;
}

.omni-group-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.omni-card {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.omni-card:hover {
  background: rgba(99, 102, 241, 0.15);
  border-color: rgba(99, 102, 241, 0.4);
  transform: translateX(4px);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.3);
}

.omni-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 6px;
  font-size: 0.78rem;
}

.omni-page-tag {
  font-weight: 600;
  color: var(--accent);
  display: flex;
  align-items: center;
  gap: 5px;
}

.omni-jump-btn {
  color: var(--text-muted);
  font-size: 0.74rem;
  transition: color var(--transition-fast);
}

.omni-card:hover .omni-jump-btn {
  color: #fff;
}

.omni-snippet {
  font-size: 0.83rem;
  line-height: 1.45;
  color: var(--text-main);
}

.omni-snippet mark {
  background: rgba(234, 179, 8, 0.35);
  color: #fef08a;
  padding: 0 3px;
  border-radius: 2px;
  font-weight: 600;
}

/* ==========================================================================
   Three.js 3D Canvas
   ========================================================================== */
.three-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  display: block;
  pointer-events: none;
  border-radius: 0;
  opacity: 0;
  transition: opacity 0.8s ease;
}

.three-canvas.visible {
  opacity: 1;
  pointer-events: auto;
}

/* Camera mode buttons */
#camera-mode-group {
  gap: 2px;
}

.cam-mode-btn.active {
  color: var(--primary) !important;
  background: rgba(124, 58, 237, 0.2) !important;
}

/* ==========================================================================
   AI Assistant Panel
   ========================================================================== */
.ai-panel {
  position: fixed;
  right: -420px;
  top: 0;
  bottom: 0;
  width: 400px;
  background: var(--surface-glass);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-left: 1px solid var(--border);
  z-index: 600;
  display: flex;
  flex-direction: column;
  transition: right 0.38s cubic-bezier(0.4, 0, 0.2, 1);
  overflow: hidden;
}

.ai-panel.open {
  right: 0;
}

.ai-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  background: rgba(124, 58, 237, 0.08);
  flex-shrink: 0;
}

.ai-panel-title {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-title);
}

.ai-panel-title i { color: var(--primary); font-size: 1.1rem; }

.ai-header-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.ai-tier-badge {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 20px;
  border: 1px solid;
  letter-spacing: 0.02em;
  background: rgba(99,102,241,0.15);
  color: #818cf8;
  border-color: rgba(99,102,241,0.4);
}

.ai-index-bar {
  padding: 8px 18px;
  font-size: 0.78rem;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.ai-index-pending { color: var(--text-muted); }
.ai-index-ready   { color: #22c55e; }

.ai-progress-wrap {
  padding: 8px 18px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.ai-progress-bar-outer {
  height: 4px;
  background: rgba(255,255,255,0.08);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 5px;
}

.ai-progress-bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 2px;
  transition: width 0.4s ease;
}

.ai-progress-msg {
  font-size: 0.74rem;
  color: var(--text-muted);
}

.ai-answer-area {
  flex: 1;
  overflow-y: auto;
  padding: 16px 18px;
  font-size: 0.87rem;
  line-height: 1.65;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.ai-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  height: 100%;
  min-height: 180px;
  color: var(--text-dim);
  text-align: center;
  font-size: 0.85rem;
}

.ai-placeholder i { font-size: 2rem; color: var(--primary); opacity: 0.6; }

.ai-answer-content {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.ai-answer-text { color: var(--text-main); white-space: pre-wrap; }

.ai-page-link {
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  padding: 1px 4px;
  border-radius: 3px;
  background: rgba(124,58,237,0.15);
  transition: background 0.15s;
}

.ai-page-link:hover { background: rgba(124,58,237,0.3); }

.ai-tier-label {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 12px;
  background: rgba(124,58,237,0.2);
  color: #a78bfa;
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.ai-sources { margin-top: 12px; border-top: 1px solid var(--border); padding-top: 10px; }
.ai-sources-title { font-size: 0.73rem; font-weight: 600; color: var(--text-muted); margin-bottom: 6px; text-transform: uppercase; letter-spacing: 0.05em; }

.ai-source-card {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 8px 10px;
  border-radius: 8px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  margin-bottom: 6px;
  cursor: pointer;
  transition: background 0.15s;
}

.ai-source-card:hover { background: rgba(124,58,237,0.12); border-color: rgba(124,58,237,0.4); }
.ai-source-page { font-size: 0.73rem; font-weight: 700; color: var(--primary); }
.ai-source-excerpt { font-size: 0.78rem; color: var(--text-muted); line-height: 1.4; }

.ai-input-area {
  padding: 14px 18px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex-shrink: 0;
  background: rgba(0,0,0,0.12);
}

.ai-input-area textarea {
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text-main);
  font-family: inherit;
  font-size: 0.87rem;
  padding: 10px 13px;
  resize: none;
  outline: none;
  transition: border-color 0.2s;
  line-height: 1.5;
}

.ai-input-area textarea:focus { border-color: var(--primary); }

.ai-input-actions {
  display: flex;
  gap: 8px;
}

.btn-summarize {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.05);
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.18s;
}

.btn-summarize:hover { background: rgba(99,102,241,0.2); color: var(--text-main); border-color: #6366f1; }

.btn-ask {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 8px 20px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  font-size: 0.87rem;
  font-weight: 700;
  border: none;
  cursor: pointer;
  transition: opacity 0.18s, transform 0.12s;
  box-shadow: 0 4px 14px rgba(124,58,237,0.45);
}

.btn-ask:hover { opacity: 0.88; transform: translateY(-1px); }
.btn-ask:active { transform: translateY(0); }

/* ==========================================================================
   Pomodoro Timer + Lo-Fi Panel
   ========================================================================== */
.pomodoro-panel {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 270px;
  background: var(--surface-glass);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--border);
  border-radius: 18px;
  z-index: 500;
  overflow: hidden;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 8px 32px rgba(0,0,0,0.45);
}

.pomodoro-panel.collapsed {
  height: 0;
  opacity: 0;
  pointer-events: none;
  bottom: -10px;
}

.pomodoro-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 13px 16px 10px;
  font-size: 0.84rem;
  font-weight: 700;
  color: var(--text-title);
  border-bottom: 1px solid var(--border);
}

.pomodoro-ring-wrap {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px 0 10px;
  position: relative;
}

.pomodoro-svg {
  width: 110px;
  height: 110px;
  transform: scaleX(-1); /* mirror so dash goes clockwise */
}

#pomodoro-ring {
  transition: stroke-dashoffset 0.5s linear, stroke 0.4s ease;
}

.pomodoro-inner {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1px;
}

.pomodoro-timer {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-title);
  font-family: 'Outfit', sans-serif;
  letter-spacing: -0.02em;
}

.pomodoro-label {
  font-size: 0.62rem;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.12em;
}

.pomodoro-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 6px 16px 12px;
}

.btn-pom {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.06);
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  transition: all 0.18s;
}

.btn-pom:hover { background: rgba(124,58,237,0.25); border-color: var(--primary); }

.pom-sessions {
  font-size: 0.76rem;
  color: var(--text-muted);
  margin-left: 4px;
}

.lofi-section {
  padding: 10px 16px 16px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.lofi-title {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.lofi-tracks {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
}

.lofi-track-btn {
  flex: 1;
  padding: 6px 4px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.04);
  color: var(--text-muted);
  font-size: 0.72rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  transition: all 0.18s;
}

.lofi-track-btn i { font-size: 0.9rem; }
.lofi-track-btn.active { background: rgba(124,58,237,0.2); border-color: var(--primary); color: #c4b5fd; }
.lofi-track-btn:hover:not(.active) { background: rgba(255,255,255,0.08); color: var(--text-main); }

.lofi-volume {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-dim);
  font-size: 0.8rem;
}

.lofi-volume input[type="range"] {
  flex: 1;
  height: 4px;
  accent-color: var(--primary);
  cursor: pointer;
}

/* ==========================================================================
   Sidebar Footer: Install PWA
   ========================================================================== */
.sidebar-footer {
  padding: 10px 12px;
  border-top: 1px solid var(--border);
  margin-top: auto;
}

.btn-install {
  width: 100%;
  padding: 9px 14px;
  border-radius: 10px;
  background: rgba(124,58,237,0.15);
  border: 1px solid rgba(124,58,237,0.4);
  color: #c4b5fd;
  font-size: 0.82rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  transition: all 0.2s;
}

.btn-install:hover { background: rgba(124,58,237,0.3); }

/* ==========================================================================
   Progress Ring in file list items
   ========================================================================== */
.file-progress-ring {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.file-progress-ring circle.track {
  fill: none;
  stroke: rgba(255,255,255,0.08);
  stroke-width: 3;
}

.file-progress-ring circle.fill {
  fill: none;
  stroke: var(--primary);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-dasharray: 75.4;
  stroke-dashoffset: 75.4;
  transform: rotate(-90deg);
  transform-origin: center;
  transition: stroke-dashoffset 0.6s ease;
}

/* ==========================================================================
   AI First-Run Onboarding Modal
   ========================================================================== */
.ai-onboard-overlay {
  position: fixed;
  inset: 0;
  z-index: 9000;
  background: rgba(5, 5, 10, 0.88);
  backdrop-filter: blur(14px) saturate(120%);
  -webkit-backdrop-filter: blur(14px) saturate(120%);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  animation: fadeInOverlay 0.3s ease;
}
.ai-onboard-overlay.hidden { display: none; }
@keyframes fadeInOverlay { from { opacity:0; } to { opacity:1; } }

.ai-onboard-card {
  background: #12131c;
  border: 1px solid rgba(124,58,237,0.35);
  border-radius: 24px;
  padding: 32px 28px 24px;
  max-width: 520px;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 20px;
  box-shadow: 0 24px 80px rgba(0,0,0,0.7);
  animation: slideUpCard 0.35s cubic-bezier(0.4,0,0.2,1);
}
@keyframes slideUpCard {
  from { opacity:0; transform:translateY(28px) scale(0.97); }
  to   { opacity:1; transform:translateY(0) scale(1); }
}
.ai-onboard-header { display:flex; align-items:center; gap:16px; }
.ai-onboard-icon-wrap {
  width:56px; height:56px; border-radius:16px;
  background:linear-gradient(135deg,#7c3aed,#06b6d4);
  display:flex; align-items:center; justify-content:center;
  font-size:1.6rem; color:#fff; flex-shrink:0;
  box-shadow:0 8px 24px rgba(124,58,237,0.45);
}
.ai-onboard-title { font-size:1.25rem; font-weight:800; color:#f1f5f9; margin:0 0 4px; font-family:'Outfit',sans-serif; }
.ai-onboard-subtitle { font-size:0.83rem; color:#94a3b8; margin:0; line-height:1.4; }
.ai-change-model-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 20px;
  padding: 4px 10px;
  cursor: pointer;
  color: #94a3b8;
  font-size: 0.78rem;
  transition: all 0.2s ease;
}
.ai-change-model-btn:hover {
  background: rgba(124, 58, 237, 0.15);
  border-color: rgba(124, 58, 237, 0.4);
  color: #c4b5fd;
}
.ai-hardware-banner {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-radius: 12px;
  background: rgba(124, 58, 237, 0.08);
  border: 1px solid rgba(124, 58, 237, 0.22);
  font-size: 0.81rem;
  color: #c4b5fd;
}
.ai-hardware-banner i { color: #06b6d4; font-size: 0.95rem; }

.ai-model-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-height: 380px;
  overflow-y: auto;
  padding-right: 4px;
}
.ai-model-options::-webkit-scrollbar { width: 5px; }
.ai-model-options::-webkit-scrollbar-thumb { background: rgba(255, 255, 255, 0.15); border-radius: 4px; }

.ai-model-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.03);
  border: 1.5px solid rgba(255, 255, 255, 0.08);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4,0,0.2,1);
  position: relative;
}
.ai-model-card:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(124, 58, 237, 0.35);
  transform: translateY(-1px);
}
.ai-model-card.selected {
  background: rgba(124, 58, 237, 0.12);
  border-color: #7c3aed;
  box-shadow: 0 4px 16px rgba(124, 58, 237, 0.25);
}
.ai-model-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}
.ai-model-card-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: #f1f5f9;
}
.ai-model-card-title strong { font-weight: 700; }
.ai-model-sub { font-size: 0.74rem; color: #94a3b8; font-weight: 400; margin-left: 2px; }
.ai-model-icon { font-size: 1.1rem; }

.ai-model-size-badge {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 9px;
  border-radius: 12px;
  white-space: nowrap;
}
.badge-heavy { background: rgba(239, 68, 68, 0.15); color: #fca5a5; border: 1px solid rgba(239, 68, 68, 0.3); }
.badge-medium { background: rgba(245, 158, 11, 0.15); color: #fcd34d; border: 1px solid rgba(245, 158, 11, 0.3); }
.badge-light { background: rgba(6, 182, 212, 0.15); color: #67e8f9; border: 1px solid rgba(6, 182, 212, 0.3); }
.badge-zero { background: rgba(34, 197, 94, 0.15); color: #86efac; border: 1px solid rgba(34, 197, 94, 0.3); }

.ai-model-desc {
  font-size: 0.78rem;
  color: #94a3b8;
  line-height: 1.4;
  padding-left: 28px;
}
.ai-model-rec-tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.72rem;
  font-weight: 700;
  color: #fbbf24;
  margin-left: 28px;
  margin-top: 2px;
}
.ai-model-rec-tag.hidden { display: none; }
.ai-onboard-progress-wrap { display:flex; flex-direction:column; gap:6px; }
.ai-onboard-progress-track { height:7px; background:rgba(255,255,255,0.07); border-radius:10px; overflow:hidden; }
.ai-onboard-progress-bar { height:100%; width:0%; background:linear-gradient(90deg,#7c3aed,#06b6d4); border-radius:10px; transition:width 0.5s ease; box-shadow:0 0 8px rgba(124,58,237,0.6); }
.ai-onboard-progress-info { display:flex; align-items:center; justify-content:space-between; font-size:0.77rem; color:#64748b; }
#onboard-progress-pct { font-weight:700; color:#a78bfa; }
.ai-onboard-privacy { display:flex; align-items:center; gap:9px; padding:10px 14px; border-radius:10px; background:rgba(34,197,94,0.07); border:1px solid rgba(34,197,94,0.18); font-size:0.78rem; color:#86efac; }
.ai-onboard-privacy i { color:#22c55e; font-size:0.9rem; }
.ai-onboard-actions { display:flex; gap:10px; }
.btn-onboard-skip { flex:1; padding:11px 16px; border-radius:12px; border:1px solid rgba(255,255,255,0.12); background:rgba(255,255,255,0.04); color:#94a3b8; font-size:0.87rem; font-weight:600; cursor:pointer; display:flex; align-items:center; justify-content:center; gap:7px; transition:all 0.18s; font-family:inherit; }
.btn-onboard-skip:hover { background:rgba(255,255,255,0.08); color:#cbd5e1; }
.btn-onboard-start { flex:1.6; padding:11px 16px; border-radius:12px; border:none; background:linear-gradient(135deg,#7c3aed,#06b6d4); color:#fff; font-size:0.9rem; font-weight:800; cursor:pointer; display:flex; align-items:center; justify-content:center; gap:8px; transition:opacity 0.18s,transform 0.12s; font-family:inherit; box-shadow:0 6px 20px rgba(124,58,237,0.4); }
.btn-onboard-start:hover { opacity:0.88; transform:translateY(-1px); }
.btn-onboard-start:active { transform:translateY(0); }
.btn-onboard-start:disabled { opacity:0.5; cursor:not-allowed; transform:none; }
.ai-onboard-wifi-hint { display:flex; align-items:center; gap:8px; font-size:0.74rem; color:#475569; justify-content:center; padding-top:2px; }
.ai-onboard-wifi-hint i { color:#7c3aed; }

/* ==========================================================================
   Zoom Hint Toast
   ========================================================================== */
.zoom-hint-toast { position:fixed; bottom:90px; left:50%; transform:translateX(-50%); background:rgba(18,19,28,0.95); border:1px solid rgba(124,58,237,0.4); border-radius:30px; padding:10px 20px; display:flex; align-items:center; gap:9px; font-size:0.82rem; color:#c4b5fd; font-weight:600; z-index:4000; box-shadow:0 6px 24px rgba(0,0,0,0.5); white-space:nowrap; pointer-events:none; animation:toastPop 0.4s cubic-bezier(0.4,0,0.2,1); }
.zoom-hint-toast.hidden { display:none; }
.zoom-hint-toast i { color:var(--primary); font-size:1rem; }
@keyframes toastPop { from { opacity:0; transform:translateX(-50%) translateY(12px); } to { opacity:1; transform:translateX(-50%) translateY(0); } }
.viewport { overflow:hidden; touch-action:pan-x pan-y; }
.flipbook-wrapper { will-change:transform; }
#zoom-level { min-width:42px; text-align:center; font-variant-numeric:tabular-nums; font-weight:600; }

/* ==========================================================================
   Scanned PDF Warning Notice & Settings Modal
   ========================================================================== */
.ai-scanned-warning-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 16px 18px;
  border-radius: 16px;
  background: rgba(245, 158, 11, 0.08);
  border: 1px solid rgba(245, 158, 11, 0.3);
  animation: fadeInOverlay 0.3s ease;
}
.ai-scanned-header {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fbbf24;
  font-size: 0.95rem;
  font-weight: 700;
}
.ai-scanned-header i { font-size: 1.2rem; }
.ai-scanned-desc {
  font-size: 0.82rem;
  color: #cbd5e1;
  line-height: 1.45;
  margin: 0;
}
.ai-scanned-status {
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: rgba(0, 0, 0, 0.25);
  padding: 10px 14px;
  border-radius: 10px;
  font-size: 0.78rem;
  color: #94a3b8;
}
.ai-scanned-status .status-row {
  display: flex;
  align-items: center;
  gap: 8px;
}
.ai-scanned-hint {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 0.79rem;
  color: #fbbf24;
  line-height: 1.4;
}

/* Settings Modal Specifics */
.settings-card {
  max-width: 540px;
  gap: 16px;
}
.settings-body {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-height: 420px;
  overflow-y: auto;
  padding-right: 4px;
}
.settings-body::-webkit-scrollbar { width: 5px; }
.settings-body::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.15); border-radius: 4px; }

.setting-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 12px 14px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.07);
}
.setting-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.84rem;
  font-weight: 700;
  color: #f1f5f9;
}
.setting-select {
  width: 100%;
  padding: 9px 12px;
  border-radius: 10px;
  background: #181926;
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #e2e8f0;
  font-size: 0.83rem;
  font-family: inherit;
  cursor: pointer;
  outline: none;
}
.setting-select:focus {
  border-color: #6366f1;
  box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.25);
}
.setting-range {
  width: 100%;
  accent-color: #34d399;
  cursor: pointer;
}
.setting-hint {
  font-size: 0.73rem;
  color: #64748b;
  margin: 2px 0 0;
  line-height: 1.3;
}
.btn-setting-danger {
  padding: 6px 12px;
  border-radius: 8px;
  border: 1px solid rgba(239, 68, 68, 0.3);
  background: rgba(239, 68, 68, 0.12);
  color: #fca5a5;
  font-size: 0.76rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.btn-setting-danger:hover {
  background: rgba(239, 68, 68, 0.25);
  color: #fff;
}

/* ==========================================================================
   Mobile Responsive Layout & Touch Budgeting Rules (@media max-width: 768px)
   ========================================================================== */
@media (max-width: 768px) {
  /* Toolbar: Compact height & scrollable icon groups */
  .top-bar {
    padding: 0 8px;
    height: 54px;
    gap: 6px;
  }
  .doc-title-group {
    max-width: 140px;
  }
  .doc-title {
    font-size: 0.85rem;
  }
  .doc-metadata {
    display: none;
  }
  .btn-icon {
    width: 36px;
    height: 36px;
    font-size: 0.95rem;
  }
  .tool-group {
    gap: 2px;
  }
  #camera-mode-group {
    display: none; /* Hide 3D camera controls on mobile screens to save topbar space */
  }

  /* Sidebar: Full overlay drawer on mobile */
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 85vw;
    max-width: 320px;
    z-index: 2500;
    box-shadow: 10px 0 30px rgba(0, 0, 0, 0.7);
  }

  /* AI Panel: Slide-up bottom sheet drawer on mobile */
  .ai-panel {
    position: fixed;
    top: auto;
    bottom: 0;
    left: 0;
    right: 0;
    width: 100vw;
    height: 85vh;
    border-radius: 24px 24px 0 0;
    z-index: 2500;
    box-shadow: 0 -10px 40px rgba(0, 0, 0, 0.8);
    transform: translateY(100%);
    transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  }
  .ai-panel.open {
    transform: translateY(0);
  }

  /* Pomodoro Panel: Bottom floating sheet on mobile */
  .pomodoro-panel {
    position: fixed;
    bottom: 12px;
    left: 50%;
    transform: translateX(-50%);
    width: 92vw;
    max-width: 360px;
    z-index: 2500;
  }
  .pomodoro-panel.collapsed {
    transform: translateX(-50%) translateY(140%);
  }

  /* Settings Modal & Selection Cards */
  .ai-onboard-card {
    padding: 20px 16px;
    border-radius: 18px;
    max-height: 90vh;
    overflow-y: auto;
  }
  .ai-model-card-title {
    font-size: 0.82rem;
  }
  .ai-model-desc {
    font-size: 0.74rem;
    padding-left: 0;
  }

  /* Viewport & Flipbook */
  .viewport {
    height: calc(100vh - 54px);
  }
  .page-placeholder {
    font-size: 0.8rem;
  }
}

/* ==========================================================================
   Universal Empty State Dropzone Landing
   ========================================================================== */
.empty-dropzone-container {
  position: absolute;
  inset: 0;
  z-index: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: radial-gradient(circle at 50% 50%, rgba(30, 27, 75, 0.4) 0%, rgba(9, 13, 22, 0.75) 100%);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  animation: fadeInOverlay 0.3s ease;
}

.empty-dropzone-container.hidden {
  display: none !important;
}

/* Center Big Brand Landing */
.center-brand-landing {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 12px;
  max-width: 520px;
  max-height: 100%;
  animation: fadeIn 0.4s ease-out;
}

.center-logo-glow-wrap {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.center-brand-logo-img {
  width: min(210px, 26vh);
  height: min(210px, 26vh);
  border-radius: 36px;
  object-fit: cover;
  box-shadow: 0 16px 50px rgba(56, 189, 248, 0.45), 0 0 40px rgba(168, 85, 247, 0.35);
  border: 2px solid rgba(255, 255, 255, 0.2);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  animation: logoPulse 3s infinite ease-in-out;
}

.center-brand-logo-img:hover {
  transform: scale(1.05);
  box-shadow: 0 24px 70px rgba(56, 189, 248, 0.65), 0 0 60px rgba(168, 85, 247, 0.6);
}

.center-brand-title {
  font-family: 'Outfit', sans-serif;
  font-size: 2.6rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  color: #ffffff;
  margin: 0;
  filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.6));
}

.center-brand-title sup {
  font-size: 1.5rem;
  top: -0.45em;
  font-weight: 900;
  background: linear-gradient(180deg, #38bdf8 0%, #818cf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.center-brand-tagline {
  font-size: 1.05rem;
  font-weight: 500;
  color: #94a3b8;
  letter-spacing: 0.5px;
  margin: 0;
}

.center-landing-hint {
  margin-top: 8px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  border-radius: 30px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: #cbd5e1;
  font-size: 0.85rem;
}

.center-landing-hint i {
  color: #38bdf8;
}

/* Sidebar Upload Box */
.sidebar-upload-box {
  padding: 12px 16px 0 16px;
}

.sidebar-dropzone-card {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 14px;
  background: rgba(17, 24, 39, 0.75);
  border: 1px dashed rgba(99, 102, 241, 0.4);
  transition: all 0.2s ease;
}

.sidebar-dropzone-card:hover {
  border-color: #38bdf8;
  background: rgba(30, 41, 59, 0.9);
}

.sidebar-dropzone-icon {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: rgba(56, 189, 248, 0.15);
  color: #38bdf8;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  flex-shrink: 0;
}

.sidebar-dropzone-text {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-width: 0;
}

.sidebar-dropzone-text strong {
  font-size: 0.82rem;
  color: #f1f5f9;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-dropzone-text span {
  font-size: 0.68rem;
  color: #94a3b8;
}

.btn-sidebar-upload {
  padding: 6px 12px;
  border-radius: 10px;
  border: none;
  background: linear-gradient(135deg, #6366f1, #38bdf8);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 5px;
  transition: opacity 0.18s ease;
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.35);
}

.btn-sidebar-upload:hover {
  opacity: 0.92;
}