/* ==========================================================================
   "Nebula" — PDF 题库平台 design system
   Modern, student-friendly. Dark mode via prefers-color-scheme / [data-theme].
   ========================================================================== */

/* ---- design tokens ------------------------------------------------------ */
:root {
  /* brand */
  --accent: #6366f1;
  --accent-strong: #4f46e5;
  --accent-soft: #eef2ff;
  --accent-glow: rgba(99, 102, 241, 0.25);
  --accent2: #14b8a6;
  --accent2-soft: #ecfdf5;

  /* surface */
  --bg: #f8fafc;
  --bg-soft: #f1f5f9;
  --surface: #ffffff;
  --surface-hover: #f8fafc;
  --surface-elevated: #ffffff;

  /* text */
  --text: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-inverse: #ffffff;

  /* border */
  --border: #e2e8f0;
  --border-light: #f1f5f9;
  --border-focus: #a5b4fc;

  /* semantic */
  --green: #10b981;
  --green-soft: #ecfdf5;
  --green-border: #a7f3d0;
  --amber: #f59e0b;
  --amber-soft: #fffbeb;
  --amber-border: #fcd34d;
  --red: #ef4444;
  --red-soft: #fef2f2;
  --red-border: #fecaca;
  --blue: #3b82f6;
  --blue-soft: #eff6ff;

  /* radius */
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 999px;

  /* shadows — layered for depth */
  --shadow-xs: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.06), 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow: 0 4px 6px rgba(15, 23, 42, 0.04), 0 2px 4px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 10px 15px rgba(15, 23, 42, 0.06), 0 4px 6px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 20px 25px rgba(15, 23, 42, 0.06), 0 8px 10px rgba(15, 23, 42, 0.04);
  --shadow-xl: 0 25px 50px rgba(15, 23, 42, 0.12);

  /* glass */
  --glass-bg: rgba(255, 255, 255, 0.72);
  --glass-border: rgba(226, 232, 240, 0.8);
  --glass-blur: saturate(180%) blur(20px);

  /* spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space: 12px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;

  /* animation */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration-fast: 150ms;
  --duration: 250ms;
  --duration-slow: 400ms;
}

/* ---- dark theme --------------------------------------------------------- */
[data-theme="dark"] {
  --bg: #1a2236;
  --bg-soft: #222b42;
  --surface: #263148;
  --surface-hover: #2d3a54;
  --surface-elevated: #2d3a54;

  --text: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-inverse: #0f172a;

  --border: #334155;
  --border-light: #1e293b;
  --border-focus: #6366f1;

  --accent-soft: #1e1b4b;
  --accent2-soft: #022c22;

  --green-soft: #022c22;
  --green-border: #065f46;
  --amber-soft: #451a03;
  --amber-border: #78350f;
  --red-soft: #450a0a;
  --red-border: #7f1d1d;
  --blue-soft: #172554;

  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.25), 0 2px 4px rgba(0, 0, 0, 0.15);
  --shadow-md: 0 10px 15px rgba(0, 0, 0, 0.3), 0 4px 6px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 20px 25px rgba(0, 0, 0, 0.35), 0 8px 10px rgba(0, 0, 0, 0.2);
  --shadow-xl: 0 25px 50px rgba(0, 0, 0, 0.5);

  --glass-bg: rgba(30, 41, 59, 0.75);
  --glass-border: rgba(51, 65, 85, 0.8);

  --accent-glow: rgba(99, 102, 241, 0.35);
}

/* ---- reset & base ------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

[hidden] { display: none !important; }

html, body { min-height: 100%; }

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font: 14px/1.6 system-ui, -apple-system, "Segoe UI", "Inter", "Microsoft YaHei", sans-serif;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background var(--duration) var(--ease-out), color var(--duration) var(--ease-out);
}

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

button { cursor: pointer; }

button:disabled, input:disabled, textarea:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

a { color: var(--accent); text-decoration: none; transition: color var(--duration-fast) var(--ease-out); }
a:hover { color: var(--accent-strong); }

/* ---- scrollbar (Webkit) ------------------------------------------------ */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ---- selection ---------------------------------------------------------- */
::selection { background: var(--accent-soft); color: var(--accent-strong); }

/* ---- focus ring --------------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   Topbar — glass-morphism sticky header
   ========================================================================== */

.topbar-spa {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding: 10px 20px;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  position: sticky;
  top: 0;
  z-index: 50;
  min-height: 60px;
  transition: background var(--duration) var(--ease-out), border-color var(--duration) var(--ease-out);
}

.brand-link {
  text-decoration: none;
  color: inherit;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.brand-link h1 {
  margin: 0;
  font-size: 18px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent) 0%, #8b5cf6 50%, var(--accent2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.3px;
}

.brand-link p {
  margin: 0;
  color: var(--text-muted);
  font-size: 11px;
  display: none;
}

@media (min-width: 640px) {
  .brand-link p { display: block; }
}

/* ---- primary nav (pill tabs) -------------------------------------------- */
.primary-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  flex: 1 1 auto;
  justify-content: center;
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  border: 1px solid transparent;
  border-radius: var(--radius-full);
  padding: 7px 14px;
  font-size: 13px;
  font-weight: 500;
  transition: all var(--duration-fast) var(--ease-out);
  position: relative;
}

.nav-link:hover {
  color: var(--text);
  background: var(--bg-soft);
}

.nav-link.active {
  color: var(--accent-strong);
  background: var(--accent-soft);
  border-color: var(--border-focus);
  font-weight: 600;
}

/* ---- user chip ---------------------------------------------------------- */
.user-chip {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-shrink: 0;
}

.user-chip .role-badge {
  max-width: 320px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ---- theme toggle ------------------------------------------------------- */
.theme-toggle {
  width: 38px;
  height: 38px;
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  background: var(--surface);
  color: var(--text-secondary);
  display: grid;
  place-items: center;
  font-size: 16px;
  transition: all var(--duration-fast) var(--ease-out);
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: var(--bg-soft);
  color: var(--text);
  border-color: var(--border-focus);
}

/* ==========================================================================
   Role badge
   ========================================================================== */

.role-badge {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 14px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--text-secondary);
  font-size: 13px;
  white-space: nowrap;
  transition: all var(--duration-fast) var(--ease-out);
}

body[data-role="user"] .role-badge {
  color: var(--green);
  border-color: var(--green-border);
  background: var(--green-soft);
}

body[data-role="super_root"] .role-badge,
body[data-role="subject_root"] .role-badge {
  color: var(--accent-strong);
  border-color: var(--border-focus);
  background: var(--accent-soft);
}

body[data-role="invalid"] .role-badge {
  color: var(--red);
  border-color: var(--red-border);
  background: var(--red-soft);
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
  min-height: 38px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px 16px;
  background: var(--surface);
  color: var(--text);
  font-weight: 500;
  font-size: 13px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: all var(--duration-fast) var(--ease-out);
  white-space: nowrap;
  text-decoration: none;
}

.btn:hover:not(:disabled) {
  background: var(--bg-soft);
  border-color: var(--border-focus);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.btn:active:not(:disabled) {
  transform: translateY(0);
  box-shadow: none;
}

.btn.primary {
  border-color: var(--accent);
  background: linear-gradient(135deg, var(--accent) 0%, #7c3aed 100%);
  color: #fff;
  font-weight: 600;
  box-shadow: 0 2px 8px var(--accent-glow);
}

.btn.primary:hover:not(:disabled) {
  background: linear-gradient(135deg, var(--accent-strong) 0%, #6d28d9 100%);
  box-shadow: 0 4px 16px var(--accent-glow);
  transform: translateY(-2px);
}

.btn.ghost {
  background: transparent;
  border-color: transparent;
}

.btn.ghost:hover:not(:disabled) {
  background: var(--bg-soft);
}

.btn.danger {
  border-color: var(--red);
  background: var(--red);
  color: #fff;
  font-weight: 600;
}

.btn.danger:hover:not(:disabled) {
  background: #dc2626;
  box-shadow: 0 2px 8px rgba(239, 68, 68, 0.25);
}

/* ==========================================================================
   Buttons — size variants
   ========================================================================== */

.btn-sm {
  min-height: 32px;
  padding: 5px 12px;
  font-size: 12px;
  border-radius: var(--radius-sm);
}

.btn-lg {
  min-height: 46px;
  padding: 10px 24px;
  font-size: 15px;
  border-radius: var(--radius-lg);
}

/* ==========================================================================
   Form controls
   ========================================================================== */

input, textarea, select {
  width: 100%;
  min-width: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  background: var(--surface);
  padding: 10px 12px;
  outline: none;
  transition: all var(--duration-fast) var(--ease-out);
  font-size: 14px;
}

textarea {
  min-height: 120px;
  resize: vertical;
}

input:focus, textarea:focus, select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2394a3b8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

label { display: grid; gap: var(--space-xs); }
label > span { color: var(--text-secondary); font-size: 13px; font-weight: 500; }

.form-grid {
  display: grid;
  gap: var(--space);
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.form-grid > .form-row { grid-column: 1 / -1; }

.form-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-sm);
}

/* ---- check row ---------------------------------------------------------- */
.check-row {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.check-row input { width: auto; }

/* ==========================================================================
   Page shell
   ========================================================================== */

.page {
  padding: var(--space-lg);
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  gap: var(--space-md);
  animation: pageIn var(--duration-slow) var(--ease-out);
}

@keyframes pageIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.96); }
  to   { opacity: 1; transform: scale(1); }
}

/* ==========================================================================
   Cards
   ========================================================================== */

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  transition: all var(--duration) var(--ease-out);
}

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

.card h2 {
  margin: 0 0 var(--space) 0;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.2px;
}

.card .muted {
  color: var(--text-muted);
  font-size: 13px;
}

.card hr {
  border: none;
  border-top: 1px solid var(--border-light);
  margin: var(--space-md) 0;
}

/* ---- card variants ------------------------------------------------------ */
.card-glass {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
}

.card-accent {
  border-left: 3px solid var(--accent);
}

/* ==========================================================================
   Tiles (subject-home dashboard)
   ========================================================================== */

.tiles {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-md);
}

.tile {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: all var(--duration) var(--ease-spring);
  position: relative;
  overflow: hidden;
}

.tile::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--accent) 0%, #8b5cf6 100%);
  opacity: 0;
  transition: opacity var(--duration) var(--ease-out);
  border-radius: var(--radius-lg);
}

.tile:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-focus);
}

.tile:hover::before {
  opacity: 0.03;
}

.tile h3 {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  position: relative;
  z-index: 1;
}

.tile-num {
  font-size: 36px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent) 0%, #8b5cf6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: var(--space-sm) 0;
  position: relative;
  z-index: 1;
  line-height: 1.2;
}

.tile p {
  margin: 0;
  color: var(--text-muted);
  font-size: 13px;
  position: relative;
  z-index: 1;
}

/* ==========================================================================
   Paper list & hit cards
   ========================================================================== */

.paper-list, .history-list, .result-list {
  display: grid;
  gap: var(--space-sm);
  margin-top: var(--space);
}

.paper-item, .history-item, .hit {
  width: 100%;
  text-align: left;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 12px 14px;
  transition: all var(--duration-fast) var(--ease-out);
  text-decoration: none;
  color: inherit;
  display: block;
}

.paper-item:hover, .hit:hover {
  border-color: var(--border-focus);
  background: var(--accent-soft);
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

.paper-item.active {
  border-color: var(--border-focus);
  background: var(--accent-soft);
  box-shadow: var(--shadow-sm);
}

.item-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 700;
  font-size: 14px;
}

.item-meta {
  margin-top: var(--space-xs);
  color: var(--text-muted);
  font-size: 12px;
  overflow-wrap: anywhere;
}

/* ---- hit card (search results) ----------------------------------------- */
.hit {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
}

.hit.clickable { cursor: pointer; }

.hit img {
  width: 72px;
  height: 72px;
  object-fit: cover;
  background: var(--bg-soft);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  transition: transform var(--duration-fast) var(--ease-out);
}

.hit:hover img { transform: scale(1.05); }

.hit-main { min-width: 0; }

.hit-main strong {
  display: block;
  overflow-wrap: anywhere;
  font-size: 14px;
}

.hit-sub {
  color: var(--text-muted);
  font-size: 12px;
  margin-top: var(--space-xs);
}

/* ==========================================================================
   Badges
   ========================================================================== */

.badge {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 2px 10px;
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--duration-fast) var(--ease-out);
}

.badge.matched, .badge.ok, .badge.user {
  background: var(--green-soft);
  color: var(--green);
}

.badge.ambiguous, .badge.warn {
  background: var(--amber-soft);
  color: var(--amber);
}

.badge.no_match {
  background: var(--red-soft);
  color: var(--red);
}

.badge.root {
  background: var(--accent-soft);
  color: var(--accent-strong);
}

/* ==========================================================================
   Status pills & lines
   ========================================================================== */

.status-pill {
  display: inline-flex;
  align-items: center;
  border-radius: var(--radius-full);
  padding: 3px 12px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
  transition: all var(--duration-fast) var(--ease-out);
}

.status-pill.ok    { color: var(--green); background: var(--green-soft); }
.status-pill.error { color: var(--red);   background: var(--red-soft); }
.status-pill.warn  { color: var(--amber); background: var(--amber-soft); }

.status-line {
  display: flex;
  align-items: center;
  min-height: 44px;
  margin-bottom: var(--space-md);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 10px 14px;
  color: var(--text-secondary);
  font-size: 13px;
  transition: all var(--duration-fast) var(--ease-out);
}

.status-line.ok {
  color: var(--green);
  background: var(--green-soft);
  border-color: var(--green-border);
}

.status-line.warn {
  color: var(--amber);
  background: var(--amber-soft);
  border-color: var(--amber-border);
}

.status-line.error {
  color: var(--red);
  background: var(--red-soft);
  border-color: var(--red-border);
}

/* ---- page alerts -------------------------------------------------------- */
.page-error {
  border: 1px solid var(--red-border);
  background: var(--red-soft);
  color: var(--red);
  padding: 14px 16px;
  border-radius: var(--radius);
  font-size: 13px;
}

.page-warning {
  border: 1px solid var(--amber-border);
  background: var(--amber-soft);
  color: var(--amber);
  padding: 14px 16px;
  border-radius: var(--radius);
  font-size: 13px;
}

/* ==========================================================================
   Empty state
   ========================================================================== */

.empty-state {
  display: grid;
  place-items: center;
  min-height: 200px;
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-soft);
  color: var(--text-muted);
  text-align: center;
  padding: var(--space-lg);
  font-size: 14px;
}

/* ==========================================================================
   Image viewer — zoom/pan replacement for static images
   ========================================================================== */

.image-panel {
  min-width: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-soft);
  transition: all var(--duration) var(--ease-out);
  position: relative;
}

.image-panel h3 {
  margin: 0;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  font-size: 14px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
}

.image-panel.empty {
  min-height: 240px;
  display: grid;
  place-items: center;
  color: var(--text-muted);
  font-size: 14px;
}

/* zoomable container */
.zoom-container {
  position: relative;
  overflow: hidden;
  cursor: zoom-in;
  background: var(--bg-soft);
  display: grid;
  place-items: center;
  min-height: 200px;
  max-height: 72vh;
  touch-action: none;
}

.zoom-container img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 72vh;
  object-fit: contain;
  transition: transform var(--duration-fast) var(--ease-out);
  pointer-events: none;
  user-select: none;
  -webkit-user-drag: none;
}

.zoom-container.zoomed {
  cursor: grab;
  overflow: auto;
}

.zoom-container.zoomed:active {
  cursor: grabbing;
}

.zoom-container.zoomed img {
  max-height: none;
  width: auto;
  min-width: 100%;
}

/* zoom controls */
.zoom-controls {
  position: absolute;
  bottom: 12px;
  right: 12px;
  display: flex;
  gap: 4px;
  z-index: 10;
  opacity: 0;
  transition: opacity var(--duration-fast) var(--ease-out);
}

.image-panel:hover .zoom-controls,
.zoom-container.zoomed .zoom-controls {
  opacity: 1;
}

.zoom-btn {
  width: 34px;
  height: 34px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  font-size: 16px;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-out);
  box-shadow: var(--shadow-sm);
}

.zoom-btn:hover {
  background: var(--bg-soft);
  border-color: var(--border-focus);
  transform: scale(1.05);
}

/* ==========================================================================
   Lightbox overlay
   ========================================================================== */

.lightbox-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(15, 23, 42, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: grid;
  place-items: center;
  padding: var(--space-lg);
  animation: fadeIn var(--duration) var(--ease-out);
  cursor: zoom-out;
}

.lightbox-overlay img {
  max-width: 95vw;
  max-height: 90vh;
  object-fit: contain;
  border-radius: var(--radius);
  box-shadow: var(--shadow-xl);
  cursor: grab;
  user-select: none;
  -webkit-user-drag: none;
  transition: transform var(--duration-fast) var(--ease-out);
}

.lightbox-overlay img:active {
  cursor: grabbing;
}

.lightbox-close {
  position: fixed;
  top: var(--space-md);
  right: var(--space-md);
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius-full);
  background: rgba(30, 41, 59, 0.8);
  color: #fff;
  font-size: 22px;
  display: grid;
  place-items: center;
  cursor: pointer;
  z-index: 1001;
  transition: all var(--duration-fast) var(--ease-out);
  backdrop-filter: blur(12px);
}

.lightbox-close:hover {
  background: rgba(239, 68, 68, 0.8);
  border-color: rgba(239, 68, 68, 0.5);
  transform: scale(1.08);
}

.lightbox-info {
  position: fixed;
  bottom: var(--space-md);
  left: 50%;
  transform: translateX(-50%);
  color: rgba(255,255,255,0.7);
  font-size: 12px;
  background: rgba(30, 41, 59, 0.7);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-full);
  padding: 6px 16px;
  backdrop-filter: blur(12px);
  z-index: 1001;
}

/* ==========================================================================
   Viewer grid
   ========================================================================== */

.viewer-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-md);
}

.viewer-grid.four {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

@media (min-width: 1024px) {
  .viewer-grid.four {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ==========================================================================
   Workspace (legacy split-pane)
   ========================================================================== */

.shell {
  display: grid;
  grid-template-columns: 380px minmax(0, 1fr);
  min-height: calc(100vh - 60px);
}

.sidebar {
  background: var(--surface);
  border-right: 1px solid var(--border);
  overflow: auto;
  max-height: calc(100vh - 60px);
  transition: background var(--duration) var(--ease-out);
}

.tabs {
  position: sticky;
  top: 0;
  z-index: 3;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  padding: 12px;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--border);
}

.tab {
  border: 1px solid transparent;
  border-radius: var(--radius);
  padding: 8px 10px;
  background: transparent;
  color: var(--text-muted);
  font-weight: 500;
  transition: all var(--duration-fast) var(--ease-out);
}

.tab.active {
  color: var(--text);
  background: var(--bg-soft);
  border-color: var(--border);
  font-weight: 600;
}

.tab:hover:not(.active) {
  color: var(--text);
  background: var(--surface-hover);
}

.panel {
  display: none;
  padding: 14px;
}

.panel.active {
  display: grid;
  gap: 14px;
}

.workspace {
  min-width: 0;
  padding: var(--space-md);
  overflow: auto;
  max-height: calc(100vh - 60px);
}

/* ---- tool blocks -------------------------------------------------------- */
.tool-block {
  min-width: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 14px;
  transition: all var(--duration) var(--ease-out);
}

.block-title, .pane-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space);
  margin-bottom: var(--space);
  flex-wrap: wrap;
}

.block-title h2, .pane-head h2 {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.2px;
}

.block-title span, .pane-head span {
  color: var(--text-muted);
  font-size: 12px;
}

/* ---- paper summary ------------------------------------------------------ */
.paper-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-soft);
  padding: 14px;
  flex-wrap: wrap;
}

/* ---- question buttons --------------------------------------------------- */
.question-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(72px, 1fr));
  gap: var(--space-sm);
}

.question-button {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  min-height: 44px;
  font-weight: 600;
  font-size: 13px;
  transition: all var(--duration-fast) var(--ease-out);
}

.question-button:hover {
  background: var(--accent-soft);
  border-color: var(--border-focus);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.question-button.no-answer {
  background: var(--amber-soft);
  border-color: var(--amber-border);
}

/* ---- drop zone (ingest) ------------------------------------------------ */
.drop-zone {
  position: relative;
  min-width: 0;
  display: grid;
  place-items: center;
  min-height: 200px;
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-soft);
  padding: var(--space-lg);
  outline: none;
  cursor: pointer;
  transition: all var(--duration) var(--ease-out);
}

.drop-zone:hover {
  border-color: var(--border-focus);
  background: var(--accent-soft);
}

.drop-zone.dragging {
  border-color: var(--accent);
  background: var(--accent-soft);
  box-shadow: 0 0 0 4px var(--accent-glow);
}

.drop-zone input { display: none; }

.drop-copy {
  display: grid;
  gap: var(--space-xs);
  text-align: center;
  color: var(--text-muted);
  pointer-events: none;
}

.drop-copy strong {
  color: var(--text);
  font-size: 16px;
  font-weight: 600;
}

.drop-zone.has-image .drop-copy { display: none; }

#imagePreview {
  display: block;
  max-width: 100%;
  max-height: 280px;
  object-fit: contain;
  background: var(--surface);
  border-radius: var(--radius-sm);
}

#imagePreview[hidden] { display: none !important; }

/* ==========================================================================
   Pill tabs (search mode switcher etc.)
   ========================================================================== */

.tabs.three {
  display: inline-flex;
  gap: 4px;
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  padding: 4px;
  background: var(--bg-soft);
}

.tabs.three .tab {
  border: none;
  border-radius: var(--radius-full);
  padding: 7px 18px;
  background: transparent;
  color: var(--text-muted);
  font-weight: 500;
  font-size: 13px;
  transition: all var(--duration-fast) var(--ease-out);
}

.tabs.three .tab.active {
  background: var(--surface);
  color: var(--text);
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}

.tabs.three .tab:hover:not(.active) {
  color: var(--text);
}

/* ==========================================================================
   Data table
   ========================================================================== */

.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

.data-table th, .data-table td {
  border-bottom: 1px solid var(--border-light);
  padding: 10px 14px;
  text-align: left;
  vertical-align: middle;
}

.data-table th {
  background: var(--bg-soft);
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.data-table tbody tr {
  transition: background var(--duration-fast) var(--ease-out);
}

.data-table tbody tr:hover {
  background: var(--surface-hover);
}

/* ---- bar cell (trends chart) ------------------------------------------- */
.bar-cell {
  position: relative;
  height: 22px;
  background: var(--bg-soft);
  border-radius: var(--radius-sm);
  overflow: hidden;
  min-width: 80px;
}

.bar-cell .bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent) 0%, #8b5cf6 100%);
  border-radius: var(--radius-sm);
  transition: width var(--duration-slow) var(--ease-out);
}

.bar-cell span {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-size: 11px;
  color: var(--text);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* ==========================================================================
   Point tree
   ========================================================================== */

.tree, .tree ul {
  list-style: none;
  padding-left: 20px;
  margin: 0;
}

.tree > li {
  padding: 5px 0;
  font-size: 14px;
}

.point-tree details > summary {
  cursor: pointer;
  padding: 6px 0;
  font-weight: 500;
  color: var(--text);
  transition: color var(--duration-fast) var(--ease-out);
}

.point-tree details > summary:hover {
  color: var(--accent);
}

.point-tree details > summary code {
  font-weight: 700;
  color: var(--accent-strong);
  background: var(--accent-soft);
  padding: 1px 6px;
  border-radius: var(--radius-sm);
  font-size: 12px;
}

/* ==========================================================================
   KV list
   ========================================================================== */

.kv {
  display: grid;
  gap: var(--space-sm);
  margin: var(--space-sm) 0;
  font-size: 13px;
}

.kv strong {
  color: var(--text-secondary);
}

/* ==========================================================================
   JSON / code output
   ========================================================================== */

.json-output {
  margin: 0;
  max-height: 500px;
  overflow: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #0f172a;
  color: #e2e8f0;
  padding: 14px;
  font-size: 12px;
  font-family: "JetBrains Mono", "Fira Code", "Cascadia Code", monospace;
  line-height: 1.7;
}

[data-theme="dark"] .json-output {
  background: #020617;
  color: #cbd5e1;
}

/* ==========================================================================
   Spinner
   ========================================================================== */

.spinner {
  width: 20px;
  height: 20px;
  display: inline-block;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: var(--radius-full);
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ---- skeleton loading --------------------------------------------------- */
.skeleton {
  background: linear-gradient(90deg, var(--bg-soft) 25%, var(--border-light) 50%, var(--bg-soft) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm);
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.skeleton-text {
  height: 14px;
  margin-bottom: var(--space-sm);
}

.skeleton-title {
  height: 22px;
  width: 60%;
  margin-bottom: var(--space);
}

.skeleton-card {
  height: 80px;
  border-radius: var(--radius);
}

.skeleton-img {
  height: 200px;
  border-radius: var(--radius);
}

/* ==========================================================================
   Actions row
   ========================================================================== */

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-top: var(--space);
}

.actions.compact {
  margin-top: 0;
  justify-content: flex-end;
}

/* ---- file row ----------------------------------------------------------- */
.file-row {
  display: grid;
  gap: 6px;
  margin-top: 10px;
}

.file-row span {
  color: var(--text-muted);
  font-size: 12px;
}

/* ---- history ------------------------------------------------------------ */
.history-item {
  display: grid;
  gap: var(--space-sm);
}

.history-actions {
  display: flex;
  justify-content: flex-end;
}

/* ---- root lock ---------------------------------------------------------- */
.root-lock {
  display: none;
  border: 1px solid var(--amber-border);
  border-radius: var(--radius);
  background: var(--amber-soft);
  color: #92400e;
  padding: 14px;
  font-size: 13px;
}

body:not([data-role="super_root"]):not([data-role="subject_root"]) .root-lock {
  display: block;
}

body:not([data-role="super_root"]):not([data-role="subject_root"]) .root-only {
  display: none;
}

/* ---- subject banner ----------------------------------------------------- */
.subject-banner h2 {
  margin-bottom: var(--space-xs);
}

/* ==========================================================================
   Login page — full-viewport image background, floating glass card.
   ========================================================================== */

body.on-login-page {
  background: #0f172a; /* fallback behind image */
}

body.on-login-page .topbar-spa,
body.on-login-page .footnote,
body.on-login-page .topbar-lang {
  display: none;
}

/* ---- full-screen background image (covers entire page) ----------------- */
.login-bg-wrap {
  position: fixed;
  inset: -5%;
  z-index: 0;
  transform: scaleX(-1); /* flip — put figure on left, away from form */
}

.login-bg {
  position: absolute;
  inset: 0;
  background: url("/ui/img/hero-bg.png") center center / cover no-repeat;
  animation: heroZoom 20s var(--ease-in-out) infinite alternate;
  filter: brightness(0.95);
}

@keyframes heroZoom {
  0%   { transform: scale(1); }
  100% { transform: scale(1.06); }
}

/* full-page soft overlay — keeps text readable */
.login-bg-overlay {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    linear-gradient(135deg, rgba(99,102,241,0.15) 0%, transparent 40%, rgba(20,184,166,0.08) 100%),
    linear-gradient(to top, rgba(15,23,42,0.55) 0%, transparent 35%);
}

body.on-login-page .page {
  padding: 0;
  max-width: none;
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  position: relative;
  overflow: hidden;
}

/* ---- hero panel (left) — brand text over the image --------------------- */
.login-hero {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
}

.login-hero-content {
  text-align: center;
  color: #fff;
  padding: var(--space-xl);
  max-width: 480px;
  animation: heroFadeIn 1.2s var(--ease-out) 0.3s both;
}

@keyframes heroFadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

.login-hero-content h1 {
  margin: 0 0 var(--space-md) 0;
  font-size: 36px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.5px;
  text-shadow: 0 2px 24px rgba(0,0,0,0.5);
}

.login-hero-content p {
  margin: 0;
  font-size: 16px;
  opacity: 0.9;
  line-height: 1.6;
  text-shadow: 0 1px 8px rgba(0,0,0,0.4);
}

.login-hero-content .hero-logo {
  font-size: 52px;
  margin-bottom: var(--space-lg);
  display: inline-block;
  animation: logoFloat 3s var(--ease-in-out) infinite;
  filter: drop-shadow(0 4px 16px rgba(0,0,0,0.3));
}

/* ---- right panel — glass form floating over the image ------------------ */
.login-form-panel {
  display: grid;
  place-items: center;
  padding: var(--space-xl);
  z-index: 1;
  position: relative;
}

body.on-login-page .login-card {
  z-index: 1;
  position: relative;
  max-width: 420px;
  width: 100%;
  animation: heroFadeIn 0.8s var(--ease-out) 0.5s both;
  /* glass — semi-transparent so the image shows through subtly */
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  border: 1px solid rgba(255, 255, 255, 0.35);
  box-shadow: 0 8px 32px rgba(15, 23, 42, 0.12), 0 2px 8px rgba(15, 23, 42, 0.06);
}

[data-theme="dark"] body.on-login-page .login-card {
  background: rgba(30, 41, 59, 0.68);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3), 0 2px 8px rgba(0, 0, 0, 0.2);
}

/* fade out the card's own star BG when over the full-page image */
body.on-login-page .login-card::before { opacity: 0.3; }
body.on-login-page .login-card .login-glow { opacity: 0.5; }

/* ---- shooting stars overlay (both panels) ------------------------------ */
.login-particles {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.login-particles .shooting-star {
  position: fixed;
}

/* ---- login utilities bar ----------------------------------------------- */
.login-utils {
  position: fixed;
  top: var(--space-md);
  right: var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  z-index: 10;
}

.login-theme-btn {
  width: 36px;
  height: 36px;
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  background: var(--surface);
  color: var(--text-secondary);
  display: grid;
  place-items: center;
  font-size: 15px;
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-out);
}

.login-theme-btn:hover {
  background: var(--bg-soft);
  border-color: var(--border-focus);
  color: var(--text);
}

/* ---- responsive — stack on mobile -------------------------------------- */
@media (max-width: 800px) {
  body.on-login-page .page {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }

  .login-hero {
    min-height: 180px;
    max-height: 260px;
  }

  .login-hero-content h1 {
    font-size: 22px;
  }

  .login-hero-content p {
    font-size: 13px;
    display: none;
  }

  .login-hero-content .hero-logo {
    font-size: 32px;
    margin-bottom: var(--space-sm);
  }

  .login-form-panel {
    padding: var(--space-md);
    align-items: start;
    padding-top: var(--space-lg);
  }
}

/* ---- keep old card styles (non-login pages) ---------------------------- */
.login-card {
  max-width: 420px;
  width: 100%;
  padding: var(--space-xl) var(--space-lg);
  position: relative;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  isolation: isolate;
}

/* ---- starry sky inside the card ---------------------------------------- */
.login-card::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    /* bright white-blue stars */
    radial-gradient(1px 1px at 8% 12%, rgba(203,213,225,0.9) 50%, transparent 50%),
    radial-gradient(0.7px 0.7px at 15% 22%, rgba(226,232,240,0.75) 50%, transparent 50%),
    radial-gradient(1.1px 1.1px at 22% 8%,  rgba(255,255,255,0.85) 50%, transparent 50%),
    radial-gradient(0.6px 0.6px at 28% 32%, rgba(203,213,225,0.7) 50%, transparent 50%),
    radial-gradient(0.9px 0.9px at 35% 15%, rgba(226,232,240,0.8) 50%, transparent 50%),
    radial-gradient(0.5px 0.5px at 42% 28%, rgba(255,255,255,0.7) 50%, transparent 50%),
    radial-gradient(1px 1px at 50% 5%,  rgba(203,213,225,0.85) 50%, transparent 50%),
    radial-gradient(0.8px 0.8px at 58% 18%, rgba(226,232,240,0.75) 50%, transparent 50%),
    radial-gradient(1.1px 1.1px at 65% 35%, rgba(255,255,255,0.8) 50%, transparent 50%),
    radial-gradient(0.6px 0.6px at 72% 12%, rgba(203,213,225,0.7) 50%, transparent 50%),
    radial-gradient(0.9px 0.9px at 78% 25%, rgba(226,232,240,0.8) 50%, transparent 50%),
    radial-gradient(0.5px 0.5px at 85% 8%,  rgba(255,255,255,0.7) 50%, transparent 50%),
    radial-gradient(1px 1px at 92% 30%, rgba(203,213,225,0.85) 50%, transparent 50%),
    radial-gradient(0.7px 0.7px at 95% 18%, rgba(226,232,240,0.75) 50%, transparent 50%),
    radial-gradient(0.6px 0.6px at 18% 38%, rgba(203,213,225,0.7) 50%, transparent 50%),
    radial-gradient(0.9px 0.9px at 55% 38%, rgba(226,232,240,0.7) 50%, transparent 50%),
    radial-gradient(0.7px 0.7px at 82% 38%, rgba(203,213,225,0.65) 50%, transparent 50%),
    radial-gradient(0.5px 0.5px at 3% 5%,   rgba(255,255,255,0.75) 50%, transparent 50%),
    radial-gradient(0.8px 0.8px at 48% 35%, rgba(226,232,240,0.7) 50%, transparent 50%),
    /* colored accent stars */
    radial-gradient(1.2px 1.2px at 40% 10%,  rgba(99,102,241,0.7) 50%, transparent 50%),
    radial-gradient(1.2px 1.2px at 70% 20%,  rgba(139,92,246,0.65) 50%, transparent 50%),
    radial-gradient(1px 1px at 88% 15%, rgba(20,184,166,0.6) 50%, transparent 50%),
    radial-gradient(1.2px 1.2px at 12% 25%,  rgba(99,102,241,0.6) 50%, transparent 50%),
    radial-gradient(0.9px 0.9px at 33% 30%,  rgba(139,92,246,0.5) 50%, transparent 50%),
    radial-gradient(1px 1px at 90% 35%,  rgba(20,184,166,0.55) 50%, transparent 50%);
  animation: starsTwinkle 3s ease-in-out infinite;
}

@keyframes starsTwinkle {
  0%, 100% { opacity: 0.75; }
  33% { opacity: 1; }
  66% { opacity: 0.82; }
}

/* ---- shooting stars — DOM elements (multiple, continuous) -------------- */
.shooting-star {
  position: absolute;
  z-index: 0;
  pointer-events: none;
  height: 1.5px;
  background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0) 15%, rgba(226,232,240,0.9) 35%, rgba(255,255,255,1) 50%, rgba(226,232,240,0.6) 65%, transparent 100%);
  border-radius: 1px;
  transform: rotate(-28deg);
  box-shadow: 0 0 8px 2px rgba(226,232,240,0.3), 0 0 16px 4px rgba(203,213,225,0.18);
}

.shooting-star:nth-child(1) { top: 15%; left: -10%; width: 90px; animation: shoot1 3.5s linear infinite; }
.shooting-star:nth-child(2) { top: 5%;  left: -10%; width: 70px; animation: shoot2 4.2s linear infinite; animation-delay: 1.8s; }
.shooting-star:nth-child(3) { top: 30%; left: -10%; width: 100px; animation: shoot3 5s linear infinite; animation-delay: 3s; }

.shooting-star::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 45%;
  width: 4px;
  height: 4px;
  background: rgba(255,255,255,0.95);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  box-shadow: 0 0 10px 3px rgba(226,232,240,0.5);
}

@keyframes shoot1 {
  0%   { transform: rotate(-28deg) translate(0, 0); opacity: 0; }
  3%   { opacity: 1; }
  18%  { transform: rotate(-28deg) translate(550px, 280px); opacity: 0; }
  100% { transform: rotate(-28deg) translate(550px, 280px); opacity: 0; }
}
@keyframes shoot2 {
  0%   { transform: rotate(-28deg) translate(0, 0); opacity: 0; }
  3%   { opacity: 1; }
  16%  { transform: rotate(-28deg) translate(520px, 220px); opacity: 0; }
  100% { transform: rotate(-28deg) translate(520px, 220px); opacity: 0; }
}
@keyframes shoot3 {
  0%   { transform: rotate(-28deg) translate(0, 0); opacity: 0; }
  2%   { opacity: 1; }
  14%  { transform: rotate(-28deg) translate(480px, 260px); opacity: 0; }
  100% { transform: rotate(-28deg) translate(480px, 260px); opacity: 0; }
}

/* remove old single shooting star pseudo-element */
.login-card::after { display: none; }

/* soft radial glow behind the form — AI ambient feel */
.login-card .login-glow {
  content: "";
  position: absolute;
  top: -60%;
  left: -30%;
  width: 160%;
  height: 160%;
  background: radial-gradient(ellipse at 50% 0%, var(--accent-soft) 0%, transparent 70%);
  opacity: 0.5;
  pointer-events: none;
  z-index: 0;
  transition: opacity var(--duration-slow) var(--ease-out);
}

[data-theme="dark"] .login-card .login-glow {
  background: radial-gradient(ellipse at 50% 0%, rgba(99,102,241,0.1) 0%, transparent 70%);
  opacity: 0.7;
}

/* ---- language switch --------------------------------------------------- */
.lang-switch {
  display: flex;
  justify-content: flex-end;
  gap: 4px;
  margin-bottom: var(--space-sm);
  position: relative;
  z-index: 1;
}

.lang-btn {
  width: 36px;
  height: 30px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-out);
}

.lang-btn:hover {
  color: var(--text);
  border-color: var(--border-focus);
}

.lang-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* ---- brand lockup ------------------------------------------------------ */
.login-brand {
  text-align: center;
  margin-bottom: var(--space-lg);
  position: relative;
  z-index: 1;
}

.login-logo {
  font-size: 48px;
  margin-bottom: var(--space-sm);
  line-height: 1;
  display: inline-block;
  animation: logoFloat 3s var(--ease-in-out) infinite;
}

@keyframes logoFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

.login-brand h2 {
  margin: 0 0 var(--space-xs) 0;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.3px;
  background: linear-gradient(135deg, var(--accent) 0%, #8b5cf6 50%, var(--accent2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 100%;
}

.login-brand .muted {
  font-size: 13px;
  color: var(--text-secondary);
}

/* ---- AI tag ------------------------------------------------------------ */
.login-ai-tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  margin-top: var(--space-sm);
  font-size: 11px;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid var(--border-focus);
  border-radius: var(--radius-full);
  padding: 4px 12px;
  position: relative;
  z-index: 1;
}

.login-ai-tag .ai-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: aiPulse 1.8s ease-in-out infinite;
}

@keyframes aiPulse {
  0%, 100% { opacity: 0.4; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.4); }
}

/* ---- fields ------------------------------------------------------------ */
.login-fields {
  display: grid;
  gap: var(--space-md);
  position: relative;
  z-index: 1;
}

.field {
  display: grid;
  gap: var(--space-xs);
}

.field label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  align-items: baseline;
  gap: var(--space-xs);
  flex-wrap: wrap;
}

.field-hint {
  font-weight: 400;
  font-size: 11px;
  color: var(--text-muted);
  white-space: nowrap;
}

.field input {
  width: 100%;
  padding: 11px 14px;
  font-size: 14px;
  border-radius: var(--radius);
  transition: all var(--duration-fast) var(--ease-out);
}

.field input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow), 0 0 20px rgba(99,102,241,0.08);
}

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

.totp-row input {
  flex: 1;
  min-width: 0;
}

.btn-text {
  background: none;
  border: none;
  color: var(--accent);
  cursor: pointer;
  font-size: 12px;
  font-weight: 500;
  padding: 4px 0;
  white-space: nowrap;
  text-decoration: underline;
  text-underline-offset: 2px;
  transition: color var(--duration-fast) var(--ease-out);
}

.btn-text:hover {
  color: var(--accent-strong);
}

/* ---- submit button ----------------------------------------------------- */
.login-submit {
  width: 100%;
  margin-top: var(--space-xs);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 2px;
  position: relative;
  z-index: 1;
  box-shadow: 0 4px 20px var(--accent-glow);
}

.login-submit:hover:not(:disabled) {
  box-shadow: 0 6px 28px rgba(99,102,241,0.4);
  transform: translateY(-2px);
}

/* ---- feedback ---------------------------------------------------------- */
.login-feedback {
  min-height: 22px;
  font-size: 13px;
  text-align: center;
  padding: var(--space-xs) 0;
  color: var(--text-muted);
  transition: color var(--duration-fast) var(--ease-out);
  position: relative;
  z-index: 1;
}

.login-feedback.is-error {
  color: var(--red);
  font-weight: 500;
}

.login-feedback.is-ok {
  color: var(--green);
  font-weight: 500;
}

/* ---- help text --------------------------------------------------------- */
.login-help {
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
  margin: var(--space-md) 0 0;
  position: relative;
  z-index: 1;
}

.login-help .btn-text {
  font-size: 13px;
}

/* ---- divider & details in login card ----------------------------------- */
.login-card hr { position: relative; z-index: 1; }
.login-card details { position: relative; z-index: 1; }

/* ---- legacy overrides --------------------------------------------------- */
.login-form .form-row { justify-content: flex-start; }
.login-card .login-form .form-row { justify-content: flex-start; }

/* ==========================================================================
   Token field & legacy auth
   ========================================================================== */

.token-field {
  display: grid;
  gap: var(--space-xs);
  min-width: 280px;
  max-width: 520px;
  flex: 1;
}

.token-field span {
  color: var(--text-muted);
  font-size: 12px;
}

.authbar {
  flex: 1;
  display: flex;
  align-items: end;
  justify-content: flex-end;
  gap: var(--space-sm);
  min-width: 0;
}

.local-auth {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-sm);
  color: var(--text-muted);
  font-size: 12px;
}

.local-auth strong { color: var(--text); }

.local-auth code {
  max-width: 280px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-soft);
  padding: 5px 8px;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.footnote {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 20px;
  color: var(--text-muted);
  font-size: 12px;
  border-top: 1px solid var(--border-light);
  transition: all var(--duration) var(--ease-out);
}

/* ==========================================================================
   Utility: link highlight
   ========================================================================== */

body[data-role="anonymous"] .nav-link { display: none; }
body[data-role="anonymous"] .user-chip { display: none; }

/* ---- topbar language switch -------------------------------------------- */
.topbar-lang { margin-right: 2px; }
.topbar-lang .lang-btn { width: 32px; height: 28px; font-size: 11px; }

/* ==========================================================================
   Skip to main content (accessibility)
   ========================================================================== */

.skip-link {
  position: absolute;
  top: -100%;
  left: 12px;
  z-index: 100;
  background: var(--accent);
  color: #fff;
  padding: 8px 16px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 13px;
  text-decoration: none;
}

.skip-link:focus {
  top: 12px;
}

/* ==========================================================================
   Responsive — tablet
   ========================================================================== */

@media (max-width: 1080px) {
  .shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    max-height: none;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .workspace {
    max-height: none;
  }
}

/* ==========================================================================
   Responsive — mobile
   ========================================================================== */

@media (max-width: 820px) {
  .topbar-spa {
    flex-wrap: wrap;
    gap: var(--space-sm);
    padding: 10px 14px;
  }

  .primary-nav {
    order: 3;
    width: 100%;
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: var(--space-xs);
  }

  .shell {
    grid-template-columns: 1fr;
  }

  .sidebar, .panel, .workspace {
    width: 100%;
    max-width: 100vw;
    overflow-x: hidden;
  }

  .panel, .workspace {
    padding: 12px;
  }

  .block-title, .pane-head {
    align-items: flex-start;
    flex-direction: column;
    gap: var(--space-xs);
  }

  .block-title span, .pane-head span {
    text-align: left;
  }

  .workspace-grid, .viewer-grid, .viewer-grid.four {
    grid-template-columns: 1fr;
  }

  .page {
    padding: var(--space);
  }

  .tiles {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  }

  .hit {
    grid-template-columns: 56px minmax(0, 1fr);
    gap: var(--space-sm);
    padding: 10px;
  }

  .hit img {
    width: 56px;
    height: 56px;
  }

  .tabs.three {
    flex-wrap: wrap;
  }

  .user-chip .role-badge {
    max-width: 180px;
    font-size: 12px;
  }
}

/* ==========================================================================
   Filter bar — inline filter row (papers, audit)
   ========================================================================== */

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 14px 0;
}

.filter-field {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
}

.filter-field span {
  color: var(--text-muted);
  font-size: 12px;
  white-space: nowrap;
}

.filter-field select,
.filter-field input {
  width: auto;
  min-width: 80px;
  padding: 7px 10px;
  font-size: 13px;
}

.filter-bar > input[type="search"] {
  flex: 1;
  min-width: 160px;
  max-width: 280px;
  padding: 7px 12px;
  font-size: 13px;
}

/* ==========================================================================
   Ingest — full-width two-column layout
   ========================================================================== */

.ingest-shell {
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: 0;
  min-height: calc(100vh - 60px - 48px);
  margin: -18px;
}

.ingest-sidebar {
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 20px;
  overflow-y: auto;
}

.ingest-main {
  padding: 20px;
  overflow-y: auto;
  background: var(--bg-soft);
}

.ingest-main {
  background: var(--surface);
  display: flex;
  flex-direction: column;
}

.ingest-main .json-output {
  max-height: none;
  min-height: 300px;
  margin: 0;
  flex: 1;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.ingest-main .empty-state {
  flex: 1;
  margin: 0;
}

.file-pick {
  display: grid;
  gap: 6px;
  padding: 16px;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-out);
  margin-bottom: var(--space);
  text-align: center;
}

.file-pick:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.file-pick input { display: none; }

.file-pick-icon {
  font-size: 24px;
  color: var(--accent);
  font-weight: 300;
}

.file-pick-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}

.file-pick-hint {
  font-size: 12px;
  color: var(--text-muted);
}

/* ==========================================================================
   Admin panel — tab panel visibility
   ========================================================================== */

.admin-panel { display: none; }
.admin-panel.active { display: block; }

@media (max-width: 800px) {
  .ingest-shell {
    grid-template-columns: 1fr;
    margin: -12px;
  }
  .ingest-sidebar { border-right: none; border-bottom: 1px solid var(--border); }
}

/* ==========================================================================
   Footer — pushed to bottom
   ========================================================================== */

.footnote {
  position: sticky;
  top: 100vh;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 20px;
  color: var(--text-muted);
  font-size: 12px;
  border-top: 1px solid var(--border-light);
  background: var(--bg);
}

/* ==========================================================================
   Motion — reduced motion preference
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ==========================================================================
   AI Chat standalone page (#/ai/chat)
   ========================================================================== */
.ai-chat-shell {
  max-width: 880px; margin: 0 auto; padding: 16px;
  display: flex; flex-direction: column; height: calc(100vh - 140px);
  background: var(--surface-elevated); border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}
.ai-chat-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 16px; border-bottom: 1px solid var(--border-light);
  background: linear-gradient(180deg, var(--accent-soft) 0%, var(--surface) 100%);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}
.ai-chat-head h2 { margin: 0; font-size: 17px; }
.ai-chat-head-actions { display: flex; align-items: center; gap: 8px; }
.ai-chat-msgs {
  flex: 1; overflow-y: auto; padding: 16px;
  display: flex; flex-direction: column; gap: 12px;
}
.ai-chat-msgs .ai-msg { /* same styles as widget */ }
.ai-chat-input {
  border-top: 1px solid var(--border-light);
  padding: 8px 12px 12px;
  background: var(--surface);
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}
.ai-pending-img {
  position: relative; display: inline-block; margin-bottom: 8px;
}
.ai-pending-img img {
  max-height: 120px; max-width: 200px; border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}
.ai-img-x {
  position: absolute; top: -8px; right: -8px;
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--text); color: var(--text-inverse);
  border: 2px solid var(--surface); cursor: pointer;
  font-size: 14px; line-height: 1; padding: 0;
}
.ai-msg-img {
  display: block; max-width: 220px; max-height: 160px;
  border-radius: var(--radius-sm); margin-bottom: 6px;
}
.ai-status {
  font-size: 12px; color: var(--text-muted); min-height: 16px;
  margin-bottom: 4px; padding: 0 4px;
}
.ai-tool-btn {
  width: 36px; height: 36px; border-radius: var(--radius-sm);
  background: var(--surface-hover); border: 1px solid var(--border);
  color: var(--text-secondary); cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.15s var(--ease-out), color 0.15s var(--ease-out);
}
.ai-tool-btn:hover { background: var(--accent-soft); color: var(--accent-strong); }
.ai-voice-btn.recording {
  background: #fee2e2; color: #dc2626; border-color: #fca5a5;
  animation: ai-pulse 1.2s ease-in-out infinite;
}
@keyframes ai-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(220, 38, 38, 0.4); }
  50%      { box-shadow: 0 0 0 8px rgba(220, 38, 38, 0); }
}

/* ==========================================================================
   AI suggestion chips on question detail page
   ========================================================================== */
.ai-suggest-row {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
  padding: 10px 12px;
  background: linear-gradient(135deg, var(--accent-soft) 0%,
                                       var(--accent2-soft) 100%);
  border: 1px solid var(--border-light);
  border-radius: var(--radius);
}
.ai-chip {
  padding: 6px 12px; font-size: 13px;
  background: var(--surface); color: var(--accent-strong);
  border: 1px solid var(--border); border-radius: var(--radius-full);
  cursor: pointer; transition: transform 0.15s var(--ease-out),
                                background 0.15s var(--ease-out);
}
.ai-chip:hover {
  transform: translateY(-1px);
  background: var(--accent); color: var(--text-inverse);
  border-color: var(--accent);
}

/* ==========================================================================
   AI Material Library admin page
   ========================================================================== */
.ai-mat-card {
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 14px; margin-bottom: 12px;
  background: var(--surface);
}
.ai-mat-card header {
  display: flex; flex-wrap: wrap; gap: 10px; align-items: center;
  margin-bottom: 8px; font-size: 12px;
}
.ai-mat-card .badge.pending  { background: #fef3c7; color: #92400e; }
.ai-mat-card .badge.approved { background: #d1fae5; color: #065f46; }
.ai-mat-card .badge.rejected { background: #fee2e2; color: #991b1b; }
.ai-mat-body { display: grid; gap: 10px;
               grid-template-columns: 1fr 1fr; margin-bottom: 10px; }
@media (max-width: 720px) { .ai-mat-body { grid-template-columns: 1fr; } }
.ai-mat-q, .ai-mat-a {
  background: var(--bg-soft); padding: 10px; border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
}
.ai-mat-q pre, .ai-mat-a pre {
  font: inherit; font-size: 13px; line-height: 1.5; white-space: pre-wrap;
  margin: 4px 0 0; max-height: 240px; overflow: auto;
}