/* ==========================================================================
   chess-fen — 2D & 3D Chessboard Recognition & Telemetry Studio
   Design System & Responsive Layout (Vanilla CSS — Token-Driven)
   ========================================================================== */

:root {
  /* Surface Hierarchy (Warm Obsidian & Slate) */
  --bg-stage: hsl(216, 36%, 5%);
  --bg-canvas: hsl(214, 32%, 7%);
  --bg-surface: hsl(214, 28%, 11%);
  --bg-elevated: hsl(214, 25%, 15%);
  --bg-interactive: hsl(214, 22%, 19%);
  --bg-interactive-hover: hsl(214, 22%, 24%);
  --bg-header-glass: hsla(214, 32%, 7%, 0.92);
  --bg-scrim: hsla(216, 36%, 5%, 0.82);

  /* Typography Colors */
  --text-primary: hsl(210, 25%, 96%);
  --text-secondary: hsl(214, 15%, 72%);
  --text-muted: hsl(214, 12%, 52%);
  --text-on-emerald: hsl(160, 80%, 5%);
  --text-on-amber: hsl(38, 85%, 6%);

  /* Tactile Chessboard Palette */
  --board-light: hsl(38, 48%, 88%);
  --board-dark: hsl(26, 38%, 42%);
  --board-border: hsl(28, 30%, 22%);
  --board-inner-border: hsl(24, 39%, 10%);
  --board-select: hsla(160, 84%, 39%, 0.48);
  --piece-drop-shadow: hsla(216, 50%, 4%, 0.38);

  /* SVG Chess Piece & Vision Overlay Palette */
  --piece-white-fill: hsl(210, 40%, 98%);
  --piece-white-stroke: hsl(222, 47%, 11%);
  --piece-black-fill: hsl(215, 28%, 17%);
  --piece-black-stroke: hsl(214, 32%, 91%);
  --piece-black-inner: hsl(215, 20%, 65%);
  --overlay-grid-line: hsla(199, 89%, 60%, 0.8);
  --overlay-quad-fill: hsla(160, 84%, 39%, 0.08);
  --overlay-halo-fill: hsla(216, 36%, 5%, 0.78);

  /* Functional Semantic Accents (Emerald, Amber, Sky, Rose — zero purple) */
  --accent-emerald: hsl(160, 84%, 39%);
  --accent-emerald-hover: hsl(160, 84%, 33%);
  --accent-emerald-soft: hsla(160, 84%, 39%, 0.14);
  --accent-emerald-text: hsl(160, 84%, 64%);
  --accent-emerald-guide: hsla(160, 84%, 55%, 0.75);

  --accent-amber: hsl(38, 92%, 50%);
  --accent-amber-soft: hsla(38, 92%, 50%, 0.16);
  --accent-amber-text: hsl(38, 95%, 74%);
  --accent-amber-heat: hsla(38, 92%, 50%, 0.28);

  --accent-sky: hsl(199, 89%, 48%);
  --accent-sky-soft: hsla(199, 89%, 48%, 0.15);
  --accent-sky-text: hsl(199, 92%, 74%);

  --accent-rose: hsl(350, 89%, 60%);
  --accent-rose-soft: hsla(350, 89%, 60%, 0.16);
  --accent-rose-text: hsl(350, 92%, 76%);
  --accent-rose-heat: hsla(350, 89%, 60%, 0.36);

  /* Borders & Dividers */
  --border-subtle: hsla(214, 20%, 80%, 0.1);
  --border-strong: hsla(214, 20%, 80%, 0.2);

  /* Shadows & Radii */
  --shadow-sm: 0 2px 8px hsla(216, 50%, 2%, 0.32);
  --shadow-md: 0 8px 24px hsla(216, 50%, 2%, 0.44);
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;

  /* Fonts */
  --font-sans: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background-color: var(--accent-emerald-soft);
  color: var(--text-primary);
}

.hidden {
  display: none !important;
}

/* ==========================================================================
   Header & Navigation Bar
   ========================================================================== */

.app-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
}

.mobile-step-nav {
  display: none;
}

.mobile-touch-hint {
  display: none;
}

.header-inner {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.brand-title {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.brand-subtitle {
  margin: 0;
  font-size: 0.78rem;
  color: var(--text-secondary);
}

.header-status-group {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  flex-wrap: wrap;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.3rem 0.65rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-emerald);
  transition: background-color 0.2s ease, box-shadow 0.2s ease;
}

.status-dot-cloud {
  background-color: var(--accent-sky);
}

.status-dot-downloading {
  background-color: var(--accent-amber);
  box-shadow: 0 2px 6px var(--accent-amber);
}

.status-dot-offline {
  background-color: var(--accent-emerald);
  box-shadow: 0 2px 6px var(--accent-emerald);
}

/* Progressive Disclosure: Debug Info Toggle & Visibility */
body:not(.debug-mode) .debug-only {
  display: none !important;
}

body.debug-mode .user-only {
  display: none !important;
}

.debug-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.34rem 0.72rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

.debug-toggle-btn:hover {
  background-color: var(--bg-elevated);
  color: var(--text-primary);
}

.debug-toggle-btn:focus-visible {
  outline: 2px solid var(--accent-emerald);
  outline-offset: 2px;
}

.debug-toggle-btn[aria-checked="true"],
.offline-toggle-btn[aria-checked="true"] {
  background-color: var(--accent-emerald-soft);
  border-color: var(--accent-emerald);
  color: var(--text-primary);
}

.debug-toggle-track {
  position: relative;
  width: 28px;
  height: 16px;
  border-radius: var(--radius-md);
  background-color: var(--bg-interactive);
  border: 1px solid var(--border-strong);
  transition: background-color 0.15s ease, border-color 0.15s ease;
  flex-shrink: 0;
}

.debug-toggle-btn[aria-checked="true"] .debug-toggle-track {
  background-color: var(--accent-emerald);
  border-color: var(--accent-emerald);
}

.debug-toggle-thumb {
  position: absolute;
  top: 1px;
  left: 1px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background-color: var(--text-secondary);
  transition: transform 0.15s ease, background-color 0.15s ease;
}

.debug-toggle-btn[aria-checked="true"] .debug-toggle-thumb {
  transform: translateX(12px);
  background-color: var(--bg-canvas);
}

/* ==========================================================================
   Main Studio Layout
   ========================================================================== */

.app-main {
  max-width: 1440px;
  margin: 0 auto;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.workspace-grid {
  display: grid;
  grid-template-columns: minmax(340px, 5fr) minmax(380px, 7fr);
  gap: 1.25rem;
  align-items: start;
}

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

.panel {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.15rem;
  box-shadow: var(--shadow-sm);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.9rem;
  flex-wrap: wrap;
}

.panel-header-actions,
.header-select-group,
.telemetry-header-controls {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  flex-wrap: wrap;
}

.panel-title {
  margin: 0;
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.panel-caption {
  font-size: 0.78rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Buttons, Inputs, Keyboard Chips & Controls
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.5rem 0.9rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.84rem;
  font-weight: 600;
  border: 1px solid var(--border-strong);
  background-color: var(--bg-elevated);
  color: var(--text-primary);
  cursor: pointer;
  transition: background-color 0.15s ease, border-color 0.15s ease, transform 0.08s ease;
  text-decoration: none;
  white-space: nowrap;
}

.btn:hover:not(:disabled) {
  background-color: var(--bg-interactive-hover);
}

.btn:active:not(:disabled) {
  transform: translateY(1px);
}

.btn:focus-visible {
  outline: 2px solid var(--accent-emerald);
  outline-offset: 2px;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.btn[aria-pressed="true"] {
  background-color: var(--accent-emerald-soft);
  border-color: var(--accent-emerald);
  color: var(--accent-emerald-text);
}

.btn-primary {
  background-color: var(--accent-emerald);
  border-color: var(--accent-emerald);
  color: var(--text-on-emerald);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--accent-emerald-hover);
  border-color: var(--accent-emerald-hover);
}

.btn-amber {
  background-color: var(--accent-amber-soft);
  border-color: var(--accent-amber);
  color: var(--accent-amber-text);
}

.btn-sm {
  padding: 0.34rem 0.68rem;
  font-size: 0.78rem;
}

.btn-xs {
  padding: 0.25rem 0.55rem;
  font-size: 0.75rem;
}

.select-input,
.text-input {
  background-color: var(--bg-canvas);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.84rem;
  padding: 0.45rem 0.7rem;
  transition: border-color 0.15s ease;
}

.select-input:focus-visible,
.text-input:focus-visible {
  outline: none;
  border-color: var(--accent-emerald);
}

.mono-input {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  width: 100%;
}

.kbd-chip {
  display: inline-block;
  padding: 0.08rem 0.36rem;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border-strong);
  background-color: var(--bg-canvas);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.3;
}

.kbd-hint {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* ==========================================================================
   Capture, Drop Zone & Visual Demo Sample Cards
   ========================================================================== */

.capture-actions-bar {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.6rem;
  margin-bottom: 0.85rem;
}

.file-input-hidden {
  display: none;
}

.camera-stage {
  position: relative;
  background-color: var(--bg-stage);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 0.85rem;
}

.camera-video {
  width: 100%;
  max-height: 380px;
  object-fit: cover;
  display: block;
}

.camera-guide-overlay {
  position: absolute;
  inset: 12%;
  border: 2px dashed var(--accent-emerald-guide);
  border-radius: var(--radius-sm);
  pointer-events: none;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: 0.5rem;
}

.camera-guide-text {
  background-color: var(--bg-scrim);
  color: var(--text-primary);
  font-size: 0.75rem;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-xs);
}

.camera-controls-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  padding: 0.65rem 0.85rem;
  background-color: var(--bg-elevated);
  border-top: 1px solid var(--border-subtle);
}

.drop-zone {
  border: 1.5px dashed var(--border-strong);
  border-radius: var(--radius-md);
  background-color: var(--bg-elevated);
  padding: 0.95rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s ease, background-color 0.15s ease;
  margin-bottom: 0.85rem;
}

.drop-zone:hover,
.drop-zone:focus-visible {
  border-color: var(--accent-emerald);
  background-color: var(--bg-interactive);
  outline: none;
}

.drop-zone.drag-over {
  border-color: var(--accent-emerald);
  background-color: var(--accent-emerald-soft);
}

.drop-zone-title {
  margin: 0 0 0.2rem 0;
  font-weight: 600;
  font-size: 0.88rem;
}

.drop-zone-hint {
  margin: 0;
  font-size: 0.76rem;
  color: var(--text-secondary);
}

/* Visual Quick Demo Cards */
.demo-strip {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  margin-bottom: 0.95rem;
}

.demo-strip-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.demo-strip-label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.demo-cards-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.5rem;
}

.demo-card {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.5rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background-color: var(--bg-elevated);
  color: var(--text-primary);
  font-family: var(--font-sans);
  text-align: left;
  cursor: pointer;
  transition: background-color 0.15s ease, border-color 0.15s ease, transform 0.08s ease;
}

.demo-card:hover:not(:disabled) {
  background-color: var(--bg-interactive-hover);
  border-color: var(--accent-emerald);
}

.demo-card:focus-visible {
  outline: 2px solid var(--accent-emerald);
  outline-offset: 2px;
}

.demo-card.active {
  background-color: var(--accent-emerald-soft);
  border-color: var(--accent-emerald);
}

.demo-card-thumb {
  width: 24px;
  height: 24px;
  max-width: 24px;
  max-height: 24px;
  border-radius: var(--radius-xs);
  object-fit: cover;
  border: 1px solid var(--border-subtle);
  background-color: var(--bg-stage);
  flex-shrink: 0;
}

.demo-card-body {
  display: flex;
  flex-direction: column;
  gap: 0.08rem;
  min-width: 0;
  flex: 1;
}

.demo-card-title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.3rem;
}

.demo-card-title {
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.demo-card-sub {
  font-size: 0.75rem;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ==========================================================================
   Vision Viewport, Empty State, Loading Overlay & 4-Corner Inspector
   ========================================================================== */

.vision-inspector-box {
  background-color: var(--bg-canvas);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.75rem;
}

.vision-tabs {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.65rem;
  flex-wrap: wrap;
}

.vision-corner-actions {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.tab-group {
  display: inline-flex;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 2px;
  flex-wrap: wrap;
}

.tab-btn {
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.32rem 0.62rem;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: background-color 0.12s ease, color 0.12s ease;
}

.tab-btn:hover {
  color: var(--text-primary);
}

.tab-btn.active {
  background-color: var(--bg-interactive);
  color: var(--text-primary);
}

.vision-stage-wrap {
  position: relative;
  width: 100%;
  min-height: 270px;
  max-height: 460px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background-color: var(--bg-stage);
  border: 1px solid var(--border-subtle);
}

.vision-canvas-inner {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  max-width: 100%;
  max-height: 440px;
  overflow: hidden;
  border-radius: var(--radius-sm);
  line-height: 0;
}

.vision-empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 1.75rem 1.25rem;
  gap: 0.45rem;
  max-width: 360px;
}

.vision-empty-icon {
  color: var(--accent-emerald);
  opacity: 0.85;
  margin-bottom: 0.15rem;
}

.vision-empty-title {
  margin: 0;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
}

.vision-empty-sub {
  margin: 0 0 0.35rem 0;
  font-size: 0.78rem;
  color: var(--text-secondary);
}

.vision-loading-overlay {
  position: absolute;
  inset: 0;
  z-index: 15;
  background-color: var(--bg-scrim);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  padding: 1rem;
  text-align: center;
  border-radius: var(--radius-sm);
}

.loading-spinner {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 3px solid var(--border-strong);
  border-top-color: var(--accent-emerald);
  animation: spin-keyframes 0.75s linear infinite;
}

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

.loading-stage-text {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-primary);
}

.vision-image {
  display: block;
  max-width: 100%;
  max-height: 440px;
  width: auto;
  height: auto;
  user-select: none;
}

.corner-svg-overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  touch-action: none;
}

.corner-handle {
  cursor: grab;
}

.corner-handle:active {
  cursor: grabbing;
}

.corner-hit-target {
  fill: transparent;
  cursor: grab;
  pointer-events: all;
}

.corner-hit-target:active {
  cursor: grabbing;
}

.corner-loupe {
  position: absolute;
  top: 0.5rem;
  left: 0.5rem;
  width: 96px;
  height: 96px;
  border-radius: var(--radius-md);
  border: 2px solid var(--accent-emerald);
  background-color: var(--bg-stage);
  box-shadow: var(--shadow-md);
  pointer-events: none;
  z-index: 20;
}

.corner-loupe.loupe-right {
  left: auto;
  right: 0.5rem;
}

.corner-loupe-canvas {
  width: 100%;
  height: 100%;
  display: block;
  border-radius: var(--radius-sm);
}

.corner-loupe-label {
  position: absolute;
  bottom: 4px;
  right: 4px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-primary);
  background-color: var(--bg-scrim);
  padding: 0.125rem 0.375rem;
  border-radius: var(--radius-xs);
}

.vision-user-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-top: 0.6rem;
  flex-wrap: wrap;
}

.vision-footer-meta-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  flex: 1;
  min-width: 0;
}

.btn-jump-to-board {
  display: none;
}

.vision-meta-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-top: 0.45rem;
  padding-top: 0.45rem;
  border-top: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
  flex-wrap: wrap;
}

/* ==========================================================================
   Right Column: Interactive 8x8 Chessboard & Diagnostics
   ========================================================================== */

.board-and-inspector-layout {
  display: grid;
  grid-template-columns: minmax(280px, 356px) minmax(300px, 1fr);
  gap: 1.1rem;
  align-items: start;
}

@media (max-width: 760px) {
  .board-and-inspector-layout {
    grid-template-columns: 1fr;
  }
}

.board-photo-peek {
  background-color: var(--bg-canvas);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  padding: 0.5rem;
  margin-bottom: 0.65rem;
}

.board-photo-peek-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.45rem;
}

.board-photo-peek-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.5rem;
  align-items: center;
}

.board-photo-peek-img {
  width: 100%;
  max-height: 150px;
  object-fit: contain;
  border-radius: var(--radius-xs);
  background-color: var(--bg-stage);
  border: 1px solid var(--border-subtle);
  display: block;
}

.chessboard-frame {
  background-color: var(--board-border);
  padding: 0.65rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  user-select: none;
}

.chessboard-grid {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  aspect-ratio: 1 / 1;
  width: 100%;
  border: 2px solid var(--board-inner-border);
  border-radius: var(--radius-xs);
  overflow: hidden;
}

.chessboard-grid:focus-visible {
  outline: 2px solid var(--accent-emerald);
  outline-offset: 4px;
}

.chess-square {
  position: relative;
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  padding: 8%;
  touch-action: none;
  transition: box-shadow 0.1s ease, background-color 0.1s ease;
}

.chess-square.light {
  background-color: var(--board-light);
}

.chess-square.dark {
  background-color: var(--board-dark);
}

.chess-square.selected {
  box-shadow: inset 0 0 0 3px var(--accent-emerald);
}

.chess-square.edited {
  box-shadow: inset 0 0 0 3px var(--accent-amber);
}

.chess-square.selected.edited {
  box-shadow: inset 0 0 0 3px var(--accent-emerald), inset 0 0 0 6px var(--accent-amber);
}

.chess-square.move-source,
.chess-square.selected.move-source {
  box-shadow: inset 0 0 0 3px var(--accent-sky);
}

.chess-square.drag-over-sq {
  box-shadow: inset 0 0 0 4px var(--accent-sky);
}

.chess-square svg.piece-svg {
  width: 100%;
  height: 100%;
  z-index: 2;
  filter: drop-shadow(0 1px 2px var(--piece-drop-shadow));
  pointer-events: none;
}

.square-coord-rank {
  position: absolute;
  top: 2px;
  left: 4px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  line-height: 1;
  z-index: 3;
  pointer-events: none;
}

.square-coord-file {
  position: absolute;
  bottom: 2px;
  right: 4px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  line-height: 1;
  z-index: 3;
  pointer-events: none;
}

.chess-square.light .square-coord-rank,
.chess-square.light .square-coord-file {
  color: var(--board-dark);
}

.chess-square.dark .square-coord-rank,
.chess-square.dark .square-coord-file {
  color: var(--board-light);
}

.square-conf-overlay {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
}

.square-conf-low {
  background-color: var(--accent-rose-heat);
}

.square-conf-mid {
  background-color: var(--accent-amber-heat);
}

.square-repair-badge {
  position: absolute;
  top: 2px;
  right: 2px;
  z-index: 4;
  background-color: var(--accent-amber);
  color: var(--text-on-amber);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.125rem 0.25rem;
  border-radius: var(--radius-xs);
  line-height: 1;
}

.board-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.45rem;
  margin-top: 0.65rem;
  flex-wrap: wrap;
}

.board-quick-actions {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-wrap: wrap;
}

/* ==========================================================================
   Square Inspector, Aligned Piece Palette & Stage Metrics
   ========================================================================== */

.inspector-stack {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

.subcard {
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.85rem;
}

.subcard-title {
  margin: 0 0 0.35rem 0;
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.square-inspector-header {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin-bottom: 0.5rem;
}

.square-inspector-title-group {
  flex: 1;
  min-width: 0;
}

.square-photo-crop-wrap {
  position: relative;
  width: 56px;
  height: 56px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--accent-emerald);
  background-color: var(--bg-stage);
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}

.square-photo-crop-canvas {
  width: 100%;
  height: 100%;
  display: block;
  border-radius: var(--radius-xs);
}

.square-photo-crop-badge {
  position: absolute;
  bottom: 2px;
  right: 2px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-primary);
  background-color: var(--bg-scrim);
  padding: 0 0.25rem;
  border-radius: var(--radius-xs);
  line-height: 1.2;
}

.uncertain-squares-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.45rem;
  padding: 0.35rem 0.5rem;
  margin-bottom: 0.55rem;
  background-color: var(--bg-canvas);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  flex-wrap: wrap;
}

.uncertain-bar-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-amber-text);
  white-space: nowrap;
}

.uncertain-squares-pills {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-wrap: wrap;
}

.uncertain-sq-pill {
  min-height: 32px;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-xs);
  border: 1px solid var(--accent-amber);
  background-color: var(--accent-amber-soft);
  color: var(--accent-amber-text);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  transition: background-color 0.12s ease, border-color 0.12s ease;
}

.uncertain-sq-pill:hover,
.uncertain-sq-pill.active {
  background-color: var(--accent-emerald-soft);
  border-color: var(--accent-emerald);
  color: var(--accent-emerald-text);
}

.kpi-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
}

@media (max-width: 600px) {
  .kpi-strip {
    grid-template-columns: repeat(2, 1fr);
  }
}

.kpi-cell {
  background-color: var(--bg-canvas);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.55rem;
}

.kpi-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  display: block;
  white-space: nowrap;
}

.kpi-value {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
}

.stage-timing-bar {
  display: flex;
  height: 8px;
  border-radius: var(--radius-xs);
  overflow: hidden;
  background-color: var(--bg-canvas);
  margin: 0.55rem 0 0.4rem 0;
}

.stage-seg-pre {
  background-color: var(--accent-sky);
}
.stage-seg-det {
  background-color: var(--accent-emerald);
}
.stage-seg-cls {
  background-color: var(--accent-amber);
}
.stage-seg-sol {
  background-color: var(--accent-rose);
}

.stage-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.prob-bars {
  display: flex;
  flex-direction: column;
  gap: 0.38rem;
  margin-bottom: 0.75rem;
}

.prob-row {
  display: grid;
  grid-template-columns: 92px 1fr 54px;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  white-space: nowrap;
}

.prob-track {
  height: 8px;
  background-color: var(--bg-canvas);
  border-radius: var(--radius-xs);
  overflow: hidden;
}

.prob-fill {
  height: 100%;
  background-color: var(--accent-emerald);
  border-radius: var(--radius-xs);
}

.palette-instructions-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.4rem;
  margin-bottom: 0;
  flex-wrap: wrap;
}

/* 6-Column Aligned Piece Palette (White Row 1, Black Row 2, Empty Full-Width Row 3) */
.piece-palette {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 0.35rem;
}

.palette-btn {
  padding: 0.32rem 0.25rem;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  transition: background-color 0.12s ease, border-color 0.12s ease;
}

.palette-btn-empty {
  grid-column: 1 / -1;
  flex-direction: row;
  gap: 0.5rem;
  padding: 0.36rem 0.6rem;
  color: var(--text-secondary);
}

.palette-btn:hover {
  background-color: var(--bg-interactive);
  border-color: var(--accent-emerald);
}

.palette-btn:focus-visible {
  outline: 2px solid var(--accent-emerald);
  outline-offset: 2px;
}

.palette-btn.active {
  border-color: var(--accent-emerald);
  background-color: var(--accent-emerald-soft);
  color: var(--text-primary);
}

.palette-btn svg {
  width: 22px;
  height: 22px;
}

/* ==========================================================================
   FEN Output, Turn/Castling Controls & Ground-Truth Tuning Feedback
   ========================================================================== */

.fen-box {
  margin-top: 0;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.top-k-hypotheses-box {
  display: flex;
  flex-direction: column;
  gap: 0.38rem;
  padding: 0.45rem 0.55rem;
  background-color: var(--bg-canvas);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
}

.top-k-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.45rem;
  flex-wrap: wrap;
}

.top-k-pills-row {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-wrap: wrap;
}

.fen-controls-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.55rem;
  flex-wrap: wrap;
  padding: 0.38rem 0.5rem;
  background-color: var(--bg-canvas);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
}

.segmented-control {
  display: inline-flex;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xs);
  padding: 2px;
}

.seg-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.24rem 0.55rem;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: background-color 0.12s ease, color 0.12s ease;
}

.seg-btn.active {
  background-color: var(--bg-interactive);
  color: var(--text-primary);
}

.turn-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  display: inline-block;
}

.turn-dot-white {
  background-color: var(--text-primary);
  border: 1px solid var(--bg-canvas);
}

.turn-dot-black {
  background-color: var(--bg-canvas);
  border: 1.5px solid var(--text-secondary);
}

.castling-group {
  display: inline-flex;
  align-items: center;
  gap: 0.28rem;
}

.castling-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-right: 0.15rem;
}

.castle-pill {
  min-width: 24px;
  height: 24px;
  padding: 0 0.35rem;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  cursor: pointer;
  transition: background-color 0.12s ease, border-color 0.12s ease, color 0.12s ease;
}

.castle-pill.active {
  background-color: var(--accent-emerald-soft);
  border-color: var(--accent-emerald);
  color: var(--accent-emerald-text);
}

.fen-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.fen-label {
  min-width: 64px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.legality-warning {
  padding: 0.38rem 0.6rem;
  border-radius: var(--radius-xs);
  background-color: var(--accent-amber-soft);
  border: 1px solid var(--accent-amber);
  color: var(--accent-amber-text);
  font-size: 0.75rem;
}

.external-links-row {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  flex-wrap: wrap;
}

.feedback-card {
  margin-top: 1rem;
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.95rem;
}

.feedback-btn-group {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tag-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0.55rem 0;
}

.tag-pill {
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border-strong);
  background-color: var(--bg-canvas);
  color: var(--text-secondary);
  font-size: 0.75rem;
  cursor: pointer;
  user-select: none;
}

.tag-pill.selected {
  background-color: var(--accent-amber-soft);
  border-color: var(--accent-amber);
  color: var(--accent-amber-text);
}

.feedback-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  margin-top: 0.75rem;
  flex-wrap: wrap;
}

.feedback-status-msg {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent-emerald);
}

/* ==========================================================================
   Telemetry & Tuning Dataset Dashboard
   ========================================================================== */

.telemetry-summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0.85rem;
  margin-bottom: 1.1rem;
}

.metric-card {
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
}

.metric-card-label {
  font-size: 0.76rem;
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.metric-card-value {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
}

.metric-card-sub {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

.logs-table-container {
  overflow-x: auto;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
}

.logs-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
}

.logs-table th,
.logs-table td {
  padding: 0.6rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--border-subtle);
}

.logs-table th {
  background-color: var(--bg-elevated);
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.75rem;
  white-space: nowrap;
}

.logs-table tbody tr {
  cursor: pointer;
  transition: background-color 0.12s ease;
}

.logs-table tbody tr:hover {
  background-color: var(--bg-interactive);
}

.table-empty-cell {
  text-align: center;
  color: var(--text-secondary);
}

.badge {
  display: inline-block;
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-xs);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
}

.badge-ok {
  background-color: var(--accent-emerald-soft);
  color: var(--accent-emerald-text);
}

.badge-warn {
  background-color: var(--accent-amber-soft);
  color: var(--accent-amber-text);
}

.badge-info {
  background-color: var(--accent-sky-soft);
  color: var(--accent-sky-text);
}

.badge-error {
  background-color: var(--accent-rose-soft);
  color: var(--accent-rose-text);
}

/* ==========================================================================
   Non-Blocking Toast Notification System
   ========================================================================== */

.toast-container {
  position: fixed;
  bottom: 1.25rem;
  right: 1.25rem;
  z-index: 90;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-width: 380px;
  pointer-events: none;
}

.toast-item {
  pointer-events: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.65rem 0.85rem;
  border-radius: var(--radius-sm);
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  box-shadow: var(--shadow-md);
  color: var(--text-primary);
  font-size: 0.8rem;
  font-weight: 500;
}

.toast-item.toast-success {
  border-color: var(--accent-emerald);
}

.toast-item.toast-warn {
  border-color: var(--accent-amber);
}

.toast-item.toast-error {
  border-color: var(--accent-rose);
}

.toast-item.toast-info {
  border-color: var(--accent-sky);
}

.toast-close-btn {
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.95rem;
  cursor: pointer;
  padding: 0 0.25rem;
  line-height: 1;
}

.toast-close-btn:hover {
  color: var(--text-primary);
}

.app-footer {
  max-width: 1440px;
  margin: 0 auto;
  padding: 1rem 1.25rem 2rem 1.25rem;
  color: var(--text-muted);
  font-size: 0.78rem;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* ==========================================================================
   Touch & Mobile Ergonomics (Coarse Pointer & <= 760px Viewports)
   ========================================================================== */

@media (hover: none) and (pointer: coarse) {
  .kbd-hint,
  .desktop-paste-hint,
  .palette-key-hint {
    display: none !important;
  }

  .mobile-touch-hint {
    display: inline;
  }
}

@media (max-width: 760px) {
  .brand-subtitle,
  .kbd-hint,
  .desktop-paste-hint,
  .palette-key-hint,
  .desktop-label-part,
  .app-header .status-badge {
    display: none !important;
  }

  .mobile-touch-hint {
    display: inline;
  }

  .header-inner {
    padding: 0.4rem 0.75rem;
    gap: 0.4rem;
    flex-direction: row;
    flex-wrap: nowrap;
    align-items: center;
    justify-content: space-between;
  }

  .brand-group {
    gap: 0.4rem;
    min-width: 0;
    flex: 1;
  }

  .brand-text-wrap {
    min-width: 0;
    overflow: hidden;
  }

  .brand-icon {
    width: 24px;
    height: 24px;
  }

  .brand-title {
    font-size: 0.92rem;
    line-height: 1.2;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .header-status-group {
    width: auto;
    gap: 0.35rem;
    flex-wrap: nowrap;
    flex-shrink: 0;
  }

  .app-header .debug-toggle-btn {
    min-height: 38px;
    padding: 0.25rem 0.55rem;
    font-size: 0.75rem;
    gap: 0.35rem;
    flex-shrink: 0;
  }

  .mobile-step-nav {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.4rem;
    padding: 0.35rem 0.75rem 0.45rem 0.75rem;
    background-color: var(--bg-canvas);
    border-top: 1px solid var(--border-subtle);
  }

  .mobile-step-btn {
    min-height: 40px;
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-strong);
    background-color: var(--bg-surface);
    color: var(--text-secondary);
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.3rem;
    cursor: pointer;
    transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
  }

  .mobile-step-btn .badge {
    white-space: nowrap;
    flex-shrink: 0;
    padding: 0.12rem 0.38rem;
  }

  .mobile-step-btn.active {
    background-color: var(--accent-emerald-soft);
    border-color: var(--accent-emerald);
    color: var(--text-primary);
  }

  .mobile-step-title-group {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    min-width: 0;
    overflow: hidden;
  }

  .mobile-step-num {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background-color: var(--bg-interactive);
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 700;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
  }

  .mobile-step-btn.active .mobile-step-num {
    background-color: var(--accent-emerald);
    color: var(--text-on-emerald);
  }

  .mobile-step-label {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .app-main {
    padding: 0.65rem;
    gap: 0.85rem;
  }

  .panel {
    padding: 0.85rem;
    scroll-margin-top: 98px;
  }

  .panel-header {
    gap: 0.5rem;
    margin-bottom: 0.65rem;
  }

  .capture-actions-bar {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.4rem;
    margin-bottom: 0.65rem;
  }

  .capture-actions-bar .btn {
    padding: 0.4rem 0.35rem;
    font-size: 0.76rem;
  }

  body:not(.debug-mode) .drop-zone {
    display: none;
  }

  .demo-strip {
    margin-bottom: 0.65rem;
  }

  .demo-cards-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.4rem;
  }

  .demo-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 0.4rem 0.25rem;
    gap: 0.25rem;
    min-height: 58px;
  }

  .demo-card-thumb {
    width: 28px;
    height: 28px;
    max-width: 28px;
    max-height: 28px;
  }

  .demo-card-body {
    width: 100%;
    align-items: center;
  }

  .demo-card-title-row {
    justify-content: center;
    width: 100%;
  }

  .demo-card-title-row .badge {
    position: absolute;
    top: 4px;
    right: 4px;
    padding: 0.08rem 0.3rem;
    font-size: 0.75rem;
    line-height: 1.1;
  }

  .demo-card-title {
    font-size: 0.75rem;
    width: 100%;
    text-align: center;
  }

  .demo-card-meta,
  .demo-card-sub {
    display: none;
  }

  .vision-inspector-box {
    padding: 0.55rem;
  }

  .vision-tabs {
    flex-direction: column;
    align-items: stretch;
    gap: 0.4rem;
    margin-bottom: 0.5rem;
  }

  .tab-group {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    width: 100%;
  }

  .tab-btn {
    padding: 0.3rem 0.25rem;
    text-align: center;
  }

  .vision-corner-actions {
    display: none;
    width: 100%;
    grid-template-columns: 1fr 2fr;
    gap: 0.4rem;
  }

  .vision-corner-actions.corners-dirty {
    display: grid;
  }

  .vision-stage-wrap {
    min-height: 210px;
    max-height: 340px;
  }

  .vision-canvas-inner,
  .vision-image {
    max-height: 320px;
  }

  .vision-user-footer {
    flex-direction: column;
    align-items: stretch;
    gap: 0.45rem;
  }

  .btn-jump-to-board {
    display: inline-flex;
    width: 100%;
  }

  .panel-header-actions {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.35rem;
  }

  .panel-header-actions .badge {
    grid-column: 1 / -1;
    justify-self: start;
  }

  .panel-header-actions .btn-sm {
    padding: 0.3rem 0.35rem;
    width: 100%;
  }

  .chessboard-frame {
    padding: 0.45rem;
  }

  .board-toolbar {
    flex-direction: column;
    align-items: stretch;
    gap: 0.4rem;
  }

  .board-quick-actions {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0.35rem;
    width: 100%;
  }

  .board-quick-actions .btn-sm {
    padding: 0.3rem 0.25rem;
    font-size: 0.75rem;
  }

  .subcard-piece-editor {
    order: -1;
  }

  .uncertain-sq-pill {
    min-height: 38px;
    padding: 0.25rem 0.55rem;
  }

  .btn,
  .btn-sm,
  .debug-toggle-btn,
  .tab-btn,
  .seg-btn,
  .top-k-pill {
    min-height: 40px;
    font-size: 0.78rem;
  }

  .btn-xs {
    min-height: 38px;
    font-size: 0.75rem;
    padding: 0.25rem 0.6rem;
  }

  .top-k-pills-row {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.35rem;
    width: 100%;
  }

  .top-k-pill {
    padding: 0.25rem 0.25rem;
    font-size: 0.75rem;
    flex-wrap: wrap;
    line-height: 1.2;
  }

  .fen-controls-row {
    flex-direction: column;
    align-items: stretch;
    gap: 0.45rem;
    padding: 0.45rem;
  }

  .segmented-control {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    width: 100%;
  }

  .castling-group {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
  }

  .castle-pill {
    min-width: 40px;
    min-height: 40px;
    flex: 1;
    max-width: 54px;
    font-size: 0.82rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .fen-label {
    min-width: 54px;
  }

  .external-links-row {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.4rem;
    width: 100%;
  }

  .external-links-row .btn-primary {
    grid-column: 1 / -1;
  }

  .palette-btn {
    min-height: 48px;
  }

  .palette-btn-empty {
    min-height: 42px;
    font-size: 0.78rem;
  }

  .text-input,
  .select-input,
  .mono-input {
    font-size: 16px;
    min-height: 42px;
  }

  .toast-container {
    left: 0.75rem;
    right: 0.75rem;
    bottom: calc(0.75rem + env(safe-area-inset-bottom, 0px));
    max-width: none;
  }
}

@media (max-width: 359px) {
  .capture-actions-bar {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .capture-actions-bar .btn-primary {
    grid-column: 1 / -1;
  }

  .top-k-pills-row {
    grid-template-columns: 1fr;
  }
}