/* ─────────────────────────────────────────────
   crtx · style.css — Carbon Design System
   Dark-first · JetBrains Mono · Electric Blue
   ───────────────────────────────────────────── */

@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600&family=Inter:wght@400;500;600&display=swap');

/* ──── TOKENS ──── */
:root {
  /* Surface */
  --canvas:        #0C0C0C;
  --canvas-raised: #161616;
  --canvas-inset:  #0A0A0A;

  /* Ink */
  --ink-primary:   #E8E8E8;
  --ink-secondary: #8A8A8A;
  --ink-tertiary:  #333333;
  --ink-ghost:     #1F1F1F;

  /* Signal */
  --accent:        #2D7FF9;
  --accent-hover:  #5A9DFF;
  --accent-subtle: rgba(45,127,249,0.10);
  --accent-glow:   rgba(45,127,249,0.30);
  --success:       #34D399;
  --error:         #F87171;
  --warning:       #FBBF24;

  /* Typography */
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
  --font-ui:   'Inter', system-ui, -apple-system, sans-serif;

  /* Spacing */
  --space-xs:  4px;
  --space-sm:  8px;
  --space-md:  12px;
  --space-lg:  16px;
  --space-xl:  20px;
  --space-2xl: 24px;
  --space-3xl: 32px;
}

/* ──── LIGHT MODE ──── */
@media (prefers-color-scheme: light) {
  :root {
    --canvas:        #FAFAFA;
    --canvas-raised: #FFFFFF;
    --canvas-inset:  #F0F0F0;
    --ink-primary:   #0A0A0A;
    --ink-secondary: #6B6B6B;
    --ink-tertiary:  #C4C4C4;
    --ink-ghost:     #E0E0E0;
    --accent-hover:  #1A6AE0;
    --accent-subtle: rgba(45,127,249,0.08);
    --accent-glow:   rgba(45,127,249,0.20);
    --success:       #1A8754;
    --error:         #DC2626;
    --warning:       #D97706;
  }
}

/* ──── RESET ──── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; overflow: hidden; }

body {
  font-family: var(--font-ui);
  background: var(--canvas);
  color: var(--ink-primary);
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

/* ──── APP HEADER ──── */
.header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: var(--space-lg) var(--space-xl);
  border-bottom: 1px solid var(--ink-tertiary);
  flex-shrink: 0;
  z-index: 10;
}

.nav-btn {
  background: none;
  border: none;
  font-size: 1.25rem;
  color: var(--ink-secondary);
  cursor: pointer;
  padding: 0;
  line-height: 1;
  font-family: var(--font-ui);
  min-width: 24px;
  min-height: 44px;
  display: flex;
  align-items: center;
  transition: color 0.15s, transform 0.1s;
}
.nav-btn:active { transform: scale(0.9); }
.nav-btn.x { transform: none; }
.nav-btn[hidden] { display: none; }

.header h1 {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--ink-secondary);
  margin-right: auto;
}

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

.settings-btn {
  background: none;
  border: none;
  color: var(--ink-secondary);
  cursor: pointer;
  font-size: 16px;
  padding: 4px;
  line-height: 1;
  min-width: 44px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  transition: background 0.15s, color 0.15s;
}
.settings-btn:hover { background: var(--canvas-raised); color: var(--ink-primary); }

/* Status LED */
.status-led {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--ink-tertiary);
  flex-shrink: 0;
  transition: background 0.3s;
}
.status-led.processing {
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent-glow);
  animation: pulse 2s infinite;
}
.status-led.success {
  background: var(--success);
  animation: flash-once 0.3s ease-out;
}
.status-led.error {
  background: var(--error);
  animation: flash-3x 0.45s ease-out;
}

@keyframes pulse { 0%, 100% { opacity: 0.6; } 50% { opacity: 1; } }
@keyframes flash-once { 0% { opacity: 1; } 100% { opacity: 0.6; } }
@keyframes flash-3x {
  0%, 33%, 66% { opacity: 1; }
  17%, 50%, 83% { opacity: 0.3; }
  100% { opacity: 0.6; }
}

/* ──── MAIN SCROLL AREA ──── */
.main {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
}

/* ──── CONCEPT LIST ──── */
.concept-list {
  padding: var(--space-xs) 0;
}

.concept-list.collapsed {
  position: sticky;
  top: 0;
  z-index: 5;
  background: var(--canvas);
  padding: 0;
}

.concept-list.collapsed + .image-grid {
  padding-top: var(--space-xl);
}

.collapsed-header {
  background: var(--canvas-raised);
  border-bottom: 1px solid var(--ink-tertiary);
  border-left-color: var(--accent) !important;
  gap: var(--space-md);
}

.collapsed-back {
  background: none;
  border: none;
  font-size: 1.1rem;
  color: var(--ink-secondary);
  cursor: pointer;
  padding: 0;
  line-height: 1;
  font-family: var(--font-ui);
  min-width: 28px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.15s;
  flex-shrink: 0;
}
.collapsed-back:hover { color: var(--ink-primary); }
.collapsed-back:active { transform: scale(0.9); }

.concept-row {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  padding: var(--space-md) var(--space-xl);
  cursor: pointer;
  border-left: 2px solid transparent;
  min-height: 44px;
  transition: background 0.1s;
}
.concept-row:hover {
  background: var(--canvas-raised);
}
.concept-row.active {
  background: var(--accent-subtle);
  border-left-color: var(--accent);
}

.concept-name {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-primary);
  flex: 1;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.concept-row.active .concept-name { color: var(--accent); }

.concept-bar {
  width: 80px;
  height: 3px;
  background: var(--ink-tertiary);
  border-radius: 1.5px;
  overflow: hidden;
  flex-shrink: 0;
}
.concept-bar-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 1.5px;
  width: 0;
  transition: width 0.3s ease-out;
}

.concept-count {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  color: var(--ink-secondary);
  width: 3ch;
  text-align: right;
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
}

/* New concept animation */
.concept-row.new {
  animation: concept-in 0.4s ease-out both;
}
@keyframes concept-in {
  from { opacity: 0.6; transform: scale(0.97); }
  to   { opacity: 1;   transform: scale(1); }
}

/* ── BREADCRUMB HEADER (B1) ── */
.breadcrumb-header {
  background: var(--canvas-raised);
  border-bottom: 1px solid var(--ink-tertiary);
  border-left: 2px solid var(--accent);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-xl);
  min-height: 44px;
}

.breadcrumb-back {
  background: none;
  border: none;
  color: var(--ink-secondary);
  cursor: pointer;
  padding: 0;
  min-width: 28px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: color 0.15s;
}
.breadcrumb-back:hover { color: var(--ink-primary); }
.breadcrumb-back:active { transform: scale(0.9); }

.breadcrumb-trail {
  display: flex;
  align-items: center;
  gap: 0;
  flex: 1;
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: none;
  -ms-overflow-style: none;
  white-space: nowrap;
  mask-image: linear-gradient(to right, black 85%, transparent 100%);
  -webkit-mask-image: linear-gradient(to right, black 85%, transparent 100%);
}
.breadcrumb-trail::-webkit-scrollbar { display: none; }

.breadcrumb-chip {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  color: var(--accent);
  cursor: pointer;
  padding: 4px 2px;
  border: none;
  background: none;
  flex-shrink: 0;
  transition: opacity 0.15s;
  position: relative;
}
.breadcrumb-chip:hover { opacity: 0.7; }
.breadcrumb-chip:hover::after {
  content: '\2715';
  font-size: 9px;
  position: absolute;
  top: 0;
  right: -6px;
  color: var(--ink-secondary);
}

.breadcrumb-sep {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-secondary);
  padding: 0 8px;
  flex-shrink: 0;
  user-select: none;
}

.breadcrumb-count {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  color: var(--ink-secondary);
  width: 3ch;
  text-align: right;
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
  margin-left: auto;
}

/* ── RELATED CONCEPTS ROW (B1) ── */
.related-concepts {
  padding: var(--space-md) var(--space-xl) var(--space-2xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.related-concepts.hidden { display: none; }

.related-label {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-secondary);
  opacity: 0.6;
}

.related-chips {
  display: flex;
  gap: var(--space-sm);
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding-bottom: 4px;
}
.related-chips::-webkit-scrollbar { display: none; }

.related-chip {
  background: var(--canvas-raised);
  border: 1px solid var(--ink-tertiary);
  border-radius: 6px;
  padding: 8px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--ink-primary);
  cursor: pointer;
  white-space: nowrap;
  flex-shrink: 0;
  transition: border-color 0.15s, background 0.15s, transform 0.1s;
  display: flex;
  align-items: center;
  gap: 6px;
}
.related-chip:hover {
  border-color: var(--accent);
  background: var(--accent-subtle);
}
.related-chip:active { transform: scale(0.96); }

.related-chip .co-count {
  font-size: 10px;
  color: var(--ink-secondary);
  font-weight: 400;
}

/* ──── DELETE PILL ──── */
.delete-pill {
  background: var(--error);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.04em;
  padding: 6px 12px;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
  min-height: 32px;
}
.delete-pill:hover { background: #EF4444; }
.delete-pill:active { transform: scale(0.95); }

/* ──── IMAGE GRID ──── */
.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(88px, 1fr));
  gap: 4px;
  padding: 0 var(--space-xl) var(--space-xl);
}
.image-grid.hidden { display: none; }

.image-cell {
  position: relative;
}

.image-cell img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 4px;
  cursor: pointer;
  display: block;
  transition: transform 0.1s;
}
.image-cell img:hover { transform: scale(1.02); }
.image-cell img:active { transform: scale(0.98); }

.image-delete {
  position: absolute;
  top: 4px;
  right: 4px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(0,0,0,0.6);
  border: none;
  color: #fff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.5;
  transition: opacity 0.15s, background 0.15s;
  padding: 0;
}
.image-delete:hover {
  opacity: 1;
  background: var(--error);
}
.image-delete:active { transform: scale(0.9); }

@media (min-width: 1024px) {
  .image-delete { opacity: 0; }
  .image-cell:hover .image-delete { opacity: 0.8; }
  .image-cell:hover .image-delete:hover { opacity: 1; }
}

/* ──── FAB ──── */
.fab {
  position: fixed;
  right: var(--space-xl);
  bottom: var(--space-xl);
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-size: 1.5rem;
  line-height: 0;
  border: none;
  cursor: pointer;
  box-shadow: 0 0 16px var(--accent-glow);
  transition: transform 0.15s, box-shadow 0.2s;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: center;
}
.fab:hover { box-shadow: 0 0 24px var(--accent-glow); }
.fab:active { transform: scale(0.94); }

/* ──── FOOTER STATS ──── */
.footer-stats {
  display: flex;
  gap: var(--space-2xl);
  padding: var(--space-md) var(--space-xl);
  border-top: 1px solid var(--ink-tertiary);
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-secondary);
  flex-shrink: 0;
}
.footer-stats span { color: var(--ink-primary); }
.footer-stats.hidden { display: none; }

/* ──── MODAL ──── */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.92);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 100;
  opacity: 0;
  transition: opacity 0.2s ease-out;
  pointer-events: none;
}
.modal.visible {
  opacity: 1;
  pointer-events: auto;
}
.modal img {
  max-width: 95%;
  max-height: 90%;
  object-fit: contain;
}

/* ──── ONBOARDING / KEY ENTRY ──── */
.onboarding {
  position: fixed;
  inset: 0;
  background: var(--canvas);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
}
.onboarding.hidden { display: none; }

.onboarding-card {
  background: var(--canvas-raised);
  border: 1px solid var(--ink-tertiary);
  border-radius: 8px;
  padding: var(--space-3xl);
  width: min(360px, 90vw);
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
  text-align: center;
}
.onboarding-card h2 {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--ink-primary);
}
.onboarding-card p {
  font-size: 13px;
  color: var(--ink-secondary);
  line-height: 1.5;
}
.onboarding-card input {
  background: var(--canvas);
  border: 1px solid var(--ink-tertiary);
  border-radius: 6px;
  padding: var(--space-md) var(--space-lg);
  color: var(--ink-primary);
  font-family: var(--font-mono);
  font-size: 13px;
  outline: none;
  transition: border-color 0.15s;
}
.onboarding-card input:focus { border-color: var(--accent); }
.onboarding-card input.error { border-color: var(--error); }

.onboarding-card .btn-primary {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: var(--space-md) var(--space-lg);
  font-family: var(--font-ui);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
  min-height: 44px;
}
.onboarding-card .btn-primary:hover { background: var(--accent-hover); }
.onboarding-card .btn-primary:active { transform: scale(0.97); }
.onboarding-card .btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }

.onboarding-card a {
  color: var(--accent);
  text-decoration: none;
  font-size: 12px;
}
.onboarding-card a:hover { text-decoration: underline; }

.onboarding-card .error-msg {
  color: var(--error);
  font-size: 12px;
  min-height: 16px;
}

/* ──── SETTINGS PANEL ──── */
.settings-panel {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 150;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}
.settings-panel.visible {
  opacity: 1;
  pointer-events: auto;
}
.settings-card {
  background: var(--canvas-raised);
  border: 1px solid var(--ink-tertiary);
  border-radius: 8px;
  padding: var(--space-2xl);
  width: min(340px, 90vw);
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}
.settings-card h3 {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-primary);
}
.settings-card .setting-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
}
.settings-card .setting-label { color: var(--ink-secondary); }
.settings-card .setting-value {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-primary);
}
.settings-card button {
  background: var(--canvas);
  border: 1px solid var(--ink-tertiary);
  border-radius: 6px;
  padding: var(--space-sm) var(--space-md);
  color: var(--ink-primary);
  font-size: 12px;
  cursor: pointer;
  transition: background 0.15s;
  min-height: 36px;
}
.settings-card button:hover { background: var(--canvas-raised); }
.settings-card .btn-danger {
  border-color: var(--error);
  color: var(--error);
}
.settings-card .btn-danger:hover { background: rgba(248,113,113,0.1); }

/* ──── EMPTY STATE ──── */
.empty-state {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-3xl);
}
.empty-state p {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--ink-secondary);
  line-height: 1.6;
}

/* ──── TOAST ──── */
.toast-container {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  pointer-events: none;
}
.toast {
  background: var(--canvas-raised);
  border: 1px solid var(--ink-tertiary);
  border-radius: 6px;
  padding: var(--space-md) var(--space-lg);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-primary);
  white-space: nowrap;
  pointer-events: auto;
  cursor: pointer;
  animation: toast-in 0.3s ease-out;
  box-shadow: 0 4px 16px rgba(0,0,0,0.3);
}
.toast.error { border-color: var(--error); color: var(--error); }
.toast.success { border-color: var(--success); color: var(--success); }
.toast.leaving { animation: toast-out 0.3s ease-in forwards; }

@keyframes toast-in { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: translateY(0); } }
@keyframes toast-out { from { opacity: 1; transform: translateY(0); } to { opacity: 0; transform: translateY(16px); } }

/* ──── DRAG-AND-DROP OVERLAY ──── */
.drop-overlay {
  position: fixed;
  inset: 0;
  background: rgba(12,12,12,0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 250;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
}
.drop-overlay.visible {
  opacity: 1;
  pointer-events: auto;
}
.drop-overlay .drop-zone {
  border: 2px dashed var(--accent);
  border-radius: 12px;
  padding: 48px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--accent);
  letter-spacing: 0.02em;
}

/* ──── PASTE GLOW ──── */
.paste-glow {
  animation: paste-flash 0.3s ease-out;
}
@keyframes paste-flash {
  0%   { box-shadow: inset 0 0 0 2px var(--accent); }
  100% { box-shadow: inset 0 0 0 0px transparent; }
}

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

/* ──── RESPONSIVE ──── */
@media (min-width: 1024px) {
  .concept-list, .image-grid, .related-concepts, .footer-stats {
    max-width: 720px;
    margin: 0 auto;
    width: 100%;
  }
}