*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #070506;
  --bg-secondary: #0d0a0b;
  --bg-tertiary: #151012;
  --bg-elevated: #1a1416;
  --bg-hover: #221a1d;
  --border: #2e2226;
  --border-subtle: rgba(255, 255, 255, 0.06);
  --text-primary: #faf8f9;
  --text-secondary: #ddd6d9;
  --text-muted: #b5adb1;
  --control-label: #f0ecee;
  --control-value: #c9c0c4;
  --accent: #e11d48;
  --accent-hover: #f43f5e;
  --accent-dim: rgba(225, 29, 72, 0.14);
  --accent-glow: rgba(225, 29, 72, 0.32);
  --danger: #ff5c6c;
  --danger-hover: #ff6b7a;
  --success: #f43f5e;
  --warning: #ffb347;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --font-ui: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --transition: 180ms cubic-bezier(0.4, 0, 0.2, 1);
  --left-panel-width: 260px;
  --right-panel-width: 320px;
  --panel-resize-gutter: 10px;
  --mobile-tab-bar-height: 52px;
}

html, body {
  height: 100%;
  overflow: hidden;
  font-family: var(--font-ui);
  font-size: 13px;
  color: var(--text-primary);
  background: var(--bg-primary);
}

/* ── App Layout ────────────────────────────── */

#app {
  display: grid;
  grid-template-columns: var(--left-panel-width) var(--panel-resize-gutter) minmax(0, 1fr) var(--panel-resize-gutter) var(--right-panel-width);
  grid-template-rows: 56px 1fr;
  height: 100vh;
  height: 100dvh;
  gap: 0;
  background: var(--bg-primary);
  min-width: 0;
}

#app.left-panel-collapsed {
  grid-template-columns: 0 0 minmax(0, 1fr) var(--panel-resize-gutter) var(--right-panel-width);
}

#app.right-panel-collapsed {
  grid-template-columns: var(--left-panel-width) var(--panel-resize-gutter) minmax(0, 1fr) 0 0;
}

#app.left-panel-collapsed.right-panel-collapsed {
  grid-template-columns: 0 0 minmax(0, 1fr) 0 0;
}

#app.left-panel-collapsed #left-panel,
#app.left-panel-collapsed #resize-gutter-left {
  display: none;
}

#app.right-panel-collapsed #right-panel,
#app.right-panel-collapsed #resize-gutter-right {
  display: none;
}

#left-panel {
  grid-column: 1;
  grid-row: 2;
  min-width: 0;
}

#resize-gutter-left {
  grid-column: 2;
  grid-row: 2;
}

#center-panel {
  grid-column: 3;
  grid-row: 2;
  min-width: 0;
}

#resize-gutter-right {
  grid-column: 4;
  grid-row: 2;
}

#right-panel {
  grid-column: 5;
  grid-row: 2;
  min-width: 0;
}

.panel-resize-gutter {
  width: var(--panel-resize-gutter);
  min-width: var(--panel-resize-gutter);
  cursor: col-resize;
  background: transparent;
  justify-self: stretch;
  align-self: stretch;
  position: relative;
  z-index: 6;
  touch-action: none;
  flex-shrink: 0;
}

.panel-resize-gutter::after {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 1px;
  transform: translateX(-50%);
  background: var(--border-subtle);
  pointer-events: none;
  transition: background var(--transition), width var(--transition);
}

.panel-resize-gutter:hover::after,
.panel-resize-gutter.is-dragging::after {
  background: var(--accent);
  width: 2px;
}

#header {
  grid-column: 1 / -1;
  grid-row: 1;
  position: relative;
  z-index: 50;
  overflow: visible;
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
  display: flex;
  align-items: center;
  padding: 0 20px;
  gap: 16px;
  border-bottom: 1px solid var(--border-subtle);
}

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

.header-logo {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  display: block;
}

#header h1 {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

#header .header-subtitle {
  color: var(--text-muted);
  font-size: 11px;
  font-weight: 400;
  margin-top: 1px;
}

.header-spacer {
  flex: 1;
}

.header-help-group {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.app-version {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--text-muted);
  user-select: none;
}

button.app-version {
  padding: 0;
  border: none;
  background: transparent;
  cursor: pointer;
  transition: color 0.15s ease;
}

button.app-version:hover {
  color: var(--text-secondary);
}

.changelog-entry {
  margin-bottom: 1.15rem;
}

.changelog-entry:last-child {
  margin-bottom: 0;
}

.changelog-entry-header {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  margin-bottom: 0.45rem;
}

.changelog-entry-header h3 {
  margin: 0;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-primary, #f4e8ec);
}

.changelog-entry-badge {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent, #e11d48);
}

.changelog-entry ul {
  margin: 0;
  padding-left: 1.15rem;
}

.changelog-entry li {
  margin-bottom: 0.35rem;
}

.changelog-entry li:last-child {
  margin-bottom: 0;
}

/* ── Left Panel (Slides) ──────────────────── */

#left-panel {
  background: var(--bg-secondary);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-right: 1px solid var(--border-subtle);
}

#left-export-section {
  border-top: 1px solid var(--border-subtle);
  padding: 14px;
  flex-shrink: 0;
}

#left-export-section .control-group {
  margin-bottom: 8px;
}

#left-export-section .control-group:last-child {
  margin-bottom: 0;
}

.panel-header {
  padding: 14px 16px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  box-sizing: border-box;
}

#left-panel > .panel-header,
#right-panel > .panel-header {
  min-height: 44px;
}

#right-panel > .panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.panel-header-label {
  min-width: 0;
}

.panel-header-actions {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

.panel-history-btn {
  width: 28px;
  height: 28px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}

.panel-history-btn:hover:not(:disabled) {
  background: var(--accent-dim);
  border-color: var(--accent);
  color: var(--accent);
}

.panel-history-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.panel-history-icon {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

.panel-collapse-btn {
  width: 28px;
  height: 28px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
  flex-shrink: 0;
}

.panel-collapse-btn:hover {
  background: var(--accent-dim);
  border-color: var(--accent);
  color: var(--accent);
}

.panel-collapse-icon {
  width: 14px;
  height: 14px;
}

.panel-expand-tab {
  position: fixed;
  z-index: 40;
  top: 50%;
  left: 0;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 10px 6px;
  border: 1px solid var(--border);
  border-left: none;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--bg-elevated);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 9px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  box-shadow: var(--shadow);
}

.panel-expand-tab svg {
  width: 14px;
  height: 14px;
}

.panel-expand-tab--right {
  left: auto;
  right: 0;
  border-left: 1px solid var(--border);
  border-right: none;
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.panel-expand-tab:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.slide-add-buttons {
  display: flex;
  gap: 6px;
  padding: 12px;
  flex-wrap: wrap;
}

.slide-add-buttons button {
  flex: 1;
  min-width: 0;
  padding: 8px 8px;
  font-size: 11px;
  font-weight: 500;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.slide-add-buttons .slide-add-icon {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

.slide-add-buttons button:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-dim);
}

#slide-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}

.slide-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 12px;
  margin-bottom: 4px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition);
  border: 1px solid transparent;
}

.slide-item:hover {
  background: var(--bg-hover);
}

.slide-item.active {
  background: var(--accent-dim);
  border-color: rgba(225, 29, 72, 0.35);
  box-shadow: 0 0 0 1px rgba(225, 29, 72, 0.1);
}

/* Theme / post-process are global; when either section is open, every list row is visually “in scope”. */
.slide-item.global-controls-scope:not(.slide-sub-item) {
  background: var(--accent-dim);
  border-color: rgba(225, 29, 72, 0.22);
  box-shadow: 0 0 0 1px rgba(225, 29, 72, 0.08);
}

.slide-sub-item.global-controls-scope {
  background: var(--accent-dim);
  border-color: rgba(225, 29, 72, 0.22);
  box-shadow: inset 3px 0 0 0 rgba(225, 29, 72, 0.35);
}

.slide-sub-item.global-controls-scope.active {
  border-color: rgba(225, 29, 72, 0.35);
  box-shadow: inset 3px 0 0 0 rgba(225, 29, 72, 0.65);
}

.slide-item .slide-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  flex-shrink: 0;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
}

.slide-item .slide-icon .slide-type-icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.slide-item .slide-icon.slide-icon-blank {
  flex-direction: column;
  gap: 1px;
  line-height: 1;
}

.slide-item .slide-icon.slide-icon-blank .slide-type-icon {
  width: 14px;
  height: 14px;
}

.slide-item .slide-bg-ordinal {
  font-size: 10px;
  font-weight: 600;
  color: var(--text-muted);
}

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

.slide-item .slide-info .slide-name {
  font-size: 12px;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  cursor: text;
  user-select: text;
}

.slide-item .slide-info .slide-header-preview {
  font-size: 11px;
  color: var(--text-secondary);
  line-height: 1.35;
  margin-top: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.slide-item .slide-info .slide-type {
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.slide-item .slide-actions {
  display: flex;
  gap: 2px;
  opacity: 0;
  transition: opacity var(--transition);
}

.slide-item:hover .slide-actions,
.slide-item.active .slide-actions,
.slide-sub-item.active .slide-actions {
  opacity: 1;
}

.slide-actions button svg {
  width: 12px;
  height: 12px;
}

.slide-list-empty {
  padding: 24px 16px;
  text-align: center;
  color: var(--text-muted);
  font-size: 12px;
  line-height: 1.5;
}

.slide-list-empty p {
  margin: 0 0 8px;
}

.slide-item .slide-actions button {
  width: 22px;
  height: 22px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  transition: all var(--transition);
}

.slide-item .slide-actions button:hover {
  color: var(--text-primary);
  background: var(--bg-tertiary);
}

.slide-item .slide-actions button.delete-btn:hover {
  color: var(--danger);
}

.slide-group {
  margin-bottom: 4px;
}

.slide-group-parent.group-selected {
  border-color: rgba(225, 29, 72, 0.2);
}

.slide-sub-item {
  margin-left: 16px;
  padding: 8px 10px;
  margin-bottom: 2px;
  font-size: 11px;
}

.slide-sub-item.active {
  background: var(--accent-dim);
  border-color: rgba(225, 29, 72, 0.35);
  box-shadow: inset 3px 0 0 0 rgba(225, 29, 72, 0.65);
}

.slide-sub-item .slide-sub-icon {
  font-size: 11px;
  font-weight: 600;
}


.slide-group .add-sub-btn {
  font-weight: 700;
  font-size: 14px;
}

/* ── Slide drag-and-drop ─────────────────── */

.slide-item.is-dragging {
  opacity: 0.35;
}

.slide-item.drag-over-top {
  border-top: 2px solid var(--accent);
  padding-top: 10px;
}

.slide-item.drag-over-bottom {
  border-bottom: 2px solid var(--accent);
  padding-bottom: 10px;
}

/* ── Slide context menu ──────────────────── */

.slide-context-menu {
  position: fixed;
  z-index: 4000;
  min-width: 160px;
  padding: 5px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(12px);
}

.slide-context-menu[hidden] {
  display: none;
}

.slide-context-menu .ctx-item {
  display: block;
  width: 100%;
  padding: 7px 12px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-ui);
  font-size: 12px;
  text-align: left;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
}

.slide-context-menu .ctx-item:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.slide-context-menu .ctx-item.ctx-danger:hover {
  background: rgba(255, 92, 108, 0.12);
  color: var(--danger);
}

.slide-context-menu .ctx-separator {
  height: 1px;
  background: var(--border-subtle);
  margin: 4px 8px;
}

/* ── Center Panel (Preview) ───────────────── */

#center-panel {
  background: radial-gradient(ellipse at center, var(--bg-secondary) 0%, var(--bg-primary) 70%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

#preview-container {
  position: relative;
  width: 100%;
  max-width: 960px;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg), 0 0 60px var(--accent-glow);
  border: 1px solid var(--border);
}

#preview-container canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

#gl-canvas {
  z-index: 1;
  /* WebGL still renders here; overlay copies pixels each frame so blends see the real background. */
  visibility: hidden;
}

#overlay-canvas {
  z-index: 2;
}

.drag-coords-hud {
  position: absolute;
  z-index: 5;
  pointer-events: none;
  padding: 5px 9px;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
  color: var(--text-primary);
  background: color-mix(in srgb, var(--bg-primary) 82%, transparent);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.08s ease, visibility 0.08s ease;
  white-space: nowrap;
}

.drag-coords-hud.is-visible {
  opacity: 1;
  visibility: visible;
}

#overlay-canvas.hovering-text {
  cursor: text;
}

#overlay-canvas.hovering-image {
  cursor: grab;
}

#overlay-canvas.dragging {
  cursor: grabbing;
}

/* ── Playback Bar ─────────────────────────── */

#playback-bar {
  width: 100%;
  max-width: 960px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 8px 8px;
  flex-wrap: wrap;
}

.playback-icon {
  width: 16px;
  height: 16px;
}

.playback-slide-name {
  font-size: 11px;
  font-weight: 500;
  color: var(--text-secondary);
  max-width: 120px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex-shrink: 1;
  min-width: 0;
}

.playback-slider-wrap {
  flex: 1;
  min-width: 80px;
}

.playback-loop-hint {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-muted);
  white-space: nowrap;
  flex-shrink: 0;
}

.playback-btn {
  width: 36px;
  height: 36px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--bg-elevated);
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  flex-shrink: 0;
  transition: all var(--transition);
}

.playback-btn:hover {
  background: var(--accent-dim);
  border-color: var(--accent);
  color: var(--accent);
}

.playback-time {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
  min-width: 36px;
  text-align: center;
  flex-shrink: 0;
}

#time-slider {
  flex: 1;
  height: 12px;
}

#time-slider::-webkit-slider-runnable-track {
  height: 6px;
}

#time-slider::-webkit-slider-thumb {
  width: 12px;
  height: 12px;
  margin-top: -3px;
}

#time-slider::-moz-range-track {
  height: 6px;
}

#time-slider::-moz-range-thumb {
  width: 12px;
  height: 12px;
}

/* ── Right Panel (Controls) ───────────────── */

#right-panel {
  background: var(--bg-secondary);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-left: 1px solid var(--border-subtle);
}

#right-panel .panel-content {
  flex: 1;
  overflow-y: auto;
  padding: 0;
}

.control-section {
  border-bottom: 1px solid var(--border-subtle);
  padding: 20px 20px;
}

.control-section-header {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  margin-bottom: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
  padding: 8px 0;
  min-height: 36px;
  border-radius: var(--radius-sm);
}

.settings-group-title--with-help {
  display: flex;
  align-items: center;
  gap: 6px;
}

.settings-group-title--with-help .control-help {
  margin-left: auto;
}

#section-text .section-header-leading .control-help {
  margin-left: 4px;
}

.control-section-header .control-help {
  flex-shrink: 0;
}

.control-section:not(.collapsed) .control-section-header {
  margin-bottom: 14px;
}

.control-section-header .section-header-leading {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.control-section-header .section-header-label {
  letter-spacing: inherit;
}

.section-header-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  color: var(--text-secondary);
}

.control-section-header .toggle-icon {
  font-size: 12px;
  transition: transform var(--transition);
  flex-shrink: 0;
  margin-left: 10px;
}

.control-section.collapsed .section-body {
  display: none;
}

.control-section.collapsed .toggle-icon {
  transform: rotate(-90deg);
}

.shader-actions-row {
  margin-bottom: 10px;
}

.control-group {
  margin-bottom: 12px;
}

.control-group:last-child {
  margin-bottom: 0;
}

.control-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  font-weight: 500;
  color: var(--control-label);
  margin-bottom: 6px;
}

.control-label .value-display {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  color: var(--control-value);
}

.control-label .value-hint {
  font-size: 11px;
  color: var(--control-value);
  font-weight: 400;
}

.control-label-title {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  min-width: 0;
}

.control-help {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  font-size: 10px;
  font-weight: 600;
  line-height: 1;
  color: var(--text-secondary);
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  cursor: help;
  flex-shrink: 0;
  user-select: none;
}

.control-help:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.control-help-popover {
  position: fixed;
  z-index: 5000;
  max-width: 280px;
  padding: 8px 10px;
  font-size: 12px;
  line-height: 1.45;
  color: var(--text-primary);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  pointer-events: auto;
}

.param-randomize-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-muted);
  cursor: pointer;
  flex-shrink: 0;
}

.param-randomize-btn:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-dim);
}

.param-randomize-btn svg {
  width: 11px;
  height: 11px;
}

/* ── Input Styles ─────────────────────────── */

/* Tick strip above shader/settings sliders (1/20 divisions; override --tick-divs when needed) */
.range-20-ticks {
  position: relative;
  display: block;
  width: 100%;
  --tick-divs: 20;
  padding-top: 6px;
  margin-top: 1px;
}

.range-20-ticks::before {
  content: '';
  position: absolute;
  left: 7px;
  right: 7px;
  top: 0;
  height: 5px;
  pointer-events: none;
  opacity: 1;
  border-radius: 2px;
  background:
    repeating-linear-gradient(
      to right,
      color-mix(in srgb, var(--text-muted) 55%, transparent) 0 1px,
      transparent 1px calc(100% / var(--tick-divs))
    ),
    linear-gradient(to right, color-mix(in srgb, var(--text-muted) 55%, transparent), color-mix(in srgb, var(--text-muted) 55%, transparent));
  background-size: 100% 100%, 1px 55%;
  background-position: 0 50%, 100% 50%;
  background-repeat: no-repeat;
}

#playback-bar .playback-slider-wrap {
  flex: 1;
  min-width: 80px;
  align-self: center;
}

#playback-bar .playback-slider-wrap .range-20-ticks {
  flex: 1;
  min-width: 0;
  align-self: center;
  margin-top: 0;
  padding-top: 5px;
}

#playback-bar .playback-slider-wrap .range-20-ticks::before {
  left: 6px;
  right: 6px;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 14px;
  background: transparent;
  outline: none;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: 6px;
  border-radius: 3px;
  background: color-mix(in srgb, var(--text-muted) 28%, var(--bg-tertiary));
  border: 1px solid var(--border);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  margin-top: -6px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-secondary);
  cursor: pointer;
  transition: transform var(--transition);
  box-shadow: 0 0 10px var(--accent-glow);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

input[type="range"]::-moz-range-track {
  height: 6px;
  border-radius: 3px;
  background: color-mix(in srgb, var(--text-muted) 28%, var(--bg-tertiary));
  border: 1px solid var(--border);
}

input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-secondary);
  cursor: pointer;
  box-shadow: 0 0 10px var(--accent-glow);
}

input[type="range"]::-moz-range-thumb:hover {
  transform: scale(1.15);
}

input[type="text"],
input[type="number"],
textarea,
select {
  width: 100%;
  padding: 8px 11px;
  border: 1px solid color-mix(in srgb, var(--text-muted) 35%, var(--border));
  border-radius: var(--radius-sm);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 500;
  outline: none;
  transition: border-color var(--transition);
}

input[type="text"]:focus,
input[type="number"]:focus,
textarea:focus,
select:focus {
  border-color: var(--accent);
}

textarea {
  resize: vertical;
  min-height: 60px;
}

select {
  cursor: pointer;
}

input[type="color"] {
  -webkit-appearance: none;
  appearance: none;
  width: 34px;
  height: 28px;
  border: 1px solid color-mix(in srgb, var(--text-muted) 35%, var(--border));
  border-radius: var(--radius-sm);
  background: none;
  cursor: pointer;
  padding: 1px;
}

input[type="color"]::-webkit-color-swatch-wrapper {
  padding: 0;
}

input[type="color"]::-webkit-color-swatch {
  border: none;
  border-radius: 2px;
}

/* ── Buttons ──────────────────────────────── */

.btn {
  padding: 8px 16px;
  border: none;
  border-radius: var(--radius-sm);
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.btn-primary {
  background: var(--accent);
  color: white;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--bg-hover);
}

.btn-danger {
  background: var(--danger);
  color: white;
}

.btn-danger:hover {
  background: var(--danger-hover);
}

.btn-block {
  width: 100%;
  justify-content: center;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ── Export Section ────────────────────────── */

.export-section-title {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
  margin-bottom: 10px;
}

.export-buttons {
  display: flex;
  gap: 8px;
}

.export-buttons .btn {
  flex: 1;
}

.progress-bar-container {
  width: 100%;
  height: 6px;
  background: var(--bg-primary);
  border-radius: 3px;
  overflow: hidden;
  margin-top: 8px;
  display: none;
}

.progress-bar-container.active {
  display: block;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-hover));
  border-radius: 3px;
  width: 0%;
  transition: width 100ms linear;
}

.progress-bar-label {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 4px;
  text-align: center;
}

.export-status {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 6px;
  text-align: center;
  display: none;
}

.export-status.active {
  display: block;
}

/* ── Image List ───────────────────────────── */

.image-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.image-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  background: var(--bg-primary);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

.image-item img {
  width: 36px;
  height: 36px;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

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

.image-item .image-name {
  font-size: 11px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.image-item .image-controls {
  display: flex;
  gap: 4px;
}

.image-item button {
  width: 22px;
  height: 22px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: var(--radius-sm);
  font-size: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.image-item button:hover {
  color: var(--danger);
  background: var(--bg-tertiary);
}

/* ── Drop zone ────────────────────────────── */

.drop-zone {
  border: 2px dashed color-mix(in srgb, var(--text-muted) 40%, var(--border));
  border-radius: var(--radius-md);
  padding: 16px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 12px;
  cursor: pointer;
  transition: all var(--transition);
}

.drop-zone:hover,
.drop-zone.dragover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-dim);
}

.drop-zone input[type="file"] {
  display: none;
}

/* ── Inline color + range combos ──────────── */

.color-range-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.color-range-row input[type="range"] {
  flex: 1;
}

/* ── Multi-value uniform (vec2/vec3) ──────── */

.vec-inputs {
  display: flex;
  gap: 6px;
}

.vec-inputs input[type="range"] {
  flex: 1;
}

.vec-inputs .range-20-ticks {
  flex: 1;
  min-width: 0;
}

.circle-picker-wrap {
  display: flex;
  justify-content: center;
  padding: 8px 0;
}

.circle-picker {
  display: block;
  cursor: pointer;
  touch-action: none;
  border-radius: 50%;
  background: var(--bg-tertiary);
}

/* ── Scrollbar ────────────────────────────── */

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

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

::-webkit-scrollbar-thumb {
  background: var(--bg-hover);
  border-radius: 4px;
}

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

/* ── Resolution selector row ──────────────── */

.resolution-row {
  display: flex;
  gap: 6px;
}

.resolution-row .btn {
  flex: 1;
  padding: 5px 6px;
  font-size: 10px;
}

.resolution-row .btn.active {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

/* ── Duration input ───────────────────────── */

.duration-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.duration-row input {
  width: 70px;
  text-align: center;
}

.duration-row span {
  font-size: 11px;
  color: var(--text-muted);
}

/* ── FPS selector ─────────────────────────── */

.fps-row {
  display: flex;
}

.fps-row .fps-input {
  width: 80px;
  padding: 6px 8px;
  font-size: 12px;
}

.format-toggle {
  display: flex;
  gap: 6px;
}

.format-toggle .btn {
  flex: 1;
  padding: 5px 8px;
  font-size: 11px;
}

.format-toggle .btn.active {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

/* ── Toggle switch ─────────────────────────── */

.toggle-switch {
  position: relative;
  display: inline-block;
  width: 36px;
  height: 20px;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  cursor: pointer;
  inset: 0;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 10px;
  transition: var(--transition);
}

.toggle-slider::before {
  content: '';
  position: absolute;
  height: 14px;
  width: 14px;
  left: 2px;
  bottom: 2px;
  background: var(--text-muted);
  border-radius: 50%;
  transition: var(--transition);
}

.toggle-switch input:checked + .toggle-slider {
  background: var(--accent-dim);
  border-color: var(--accent);
}

.toggle-switch input:checked + .toggle-slider::before {
  transform: translateX(16px);
  background: var(--accent);
}

/* ── Modal / Overlay ──────────────────────── */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  display: none;
}

.modal-overlay.active {
  display: flex;
}

.modal {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 28px;
  max-width: 480px;
  width: 90%;
  box-shadow: var(--shadow-lg);
}

.modal h2 {
  font-size: 16px;
  margin-bottom: 16px;
}

/* ── Shader Error Overlay ─────────────────── */

#shader-error {
  position: absolute;
  bottom: 12px;
  left: 12px;
  right: 12px;
  background: rgba(255, 92, 108, 0.95);
  color: white;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.5;
  max-height: 120px;
  overflow-y: auto;
  z-index: 10;
  display: none;
  white-space: pre-wrap;
  word-break: break-word;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

#shader-error.active {
  display: block;
}

/* ── Slide name edit ──────────────────────── */

.slide-name-input {
  background: var(--bg-primary);
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 12px;
  padding: 1px 4px;
  width: 100%;
  outline: none;
}

/* ── Settings Dropdown ────────────────────── */

#settings-menu-wrap {
  position: relative;
  z-index: 1;
}

.settings-dropdown {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: 8px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 0;
  min-width: min(400px, calc(100vw - 32px));
  max-width: min(560px, calc(100vw - 24px));
  max-height: min(780px, calc(100vh - 48px));
  max-height: min(780px, calc(100dvh - 48px));
  overflow-x: hidden;
  overflow-y: auto;
  overscroll-behavior: contain;
  z-index: 200;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
}

.settings-dropdown.settings-dropdown--inline {
  position: static;
  margin: 0;
  max-width: none;
  max-height: none;
  min-width: 0;
  width: 100%;
  border: none;
  border-radius: 0;
  box-shadow: none;
  background: transparent;
}

.settings-dropdown-header {
  padding: 12px 16px 10px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

.settings-tabs {
  display: flex;
  gap: 0;
  padding: 0 12px;
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

.settings-tab {
  flex: 1;
  min-width: 0;
  padding: 10px 6px;
  border: none;
  border-bottom: 2px solid transparent;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-ui);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition);
}

.settings-tab:hover {
  color: var(--text-secondary);
}

.settings-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.settings-tab-panels {
  padding: 14px 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  overflow-y: auto;
}

.settings-tab-panel {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.settings-field-hint {
  font-size: 11px;
  color: var(--control-value);
  margin-bottom: 4px;
  line-height: 1.4;
}

.settings-group {
  min-width: 0;
}

.settings-group-title {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  margin: 0 0 8px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border-subtle);
}

.settings-grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px 14px;
  align-items: start;
}

.settings-grid-2--stack-gap {
  margin-top: 8px;
}

.settings-field {
  min-width: 0;
}

.settings-field--full {
  grid-column: 1 / -1;
}

.settings-field .control-label {
  margin-bottom: 4px;
}

.settings-inline-row {
  display: flex;
  align-items: stretch;
  gap: 8px;
  margin-top: 6px;
}

.settings-inline-row .custom-font-input {
  flex: 1;
  min-width: 0;
}

.settings-inline-btn {
  flex-shrink: 0;
  padding: 6px 12px;
  font-size: 11px;
  white-space: nowrap;
}

.settings-timer-grid .control-group {
  margin-bottom: 6px;
}

.settings-timer-grid .control-group:last-child {
  margin-bottom: 0;
}

@media (max-width: 440px) {
  .settings-grid-2 {
    grid-template-columns: 1fr;
  }

  .settings-grid-2--stack-gap {
    margin-top: 0;
  }
}

.settings-io-row {
  display: flex;
  gap: 0;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--border);
}

.settings-io-row .btn {
  flex: 1;
  padding: 5px 6px;
  font-size: 10px;
  border: none;
  border-radius: 0;
}

.settings-io-row .btn:not(:last-child) {
  border-right: 1px solid var(--border);
}

#settings-shadow-slider,
#settings-outline-slider {
  margin-top: 2px;
}

.settings-dropdown select {
  margin-top: 4px;
}

.font-select-row {
  display: flex;
  align-items: stretch;
  gap: 6px;
  margin-top: 4px;
}

.font-select-row select {
  flex: 1;
  min-width: 0;
  margin-top: 0;
}

.font-favorite-btn {
  flex-shrink: 0;
  width: 34px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
  transition: background 0.12s ease, border-color 0.12s ease;
}

.font-favorite-btn:hover {
  background: var(--bg-hover);
  border-color: #3d2a2e;
}

.font-favorite-btn[aria-pressed='true'] {
  color: var(--accent);
}

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

/* ── Mobile tab bar ─────────────────────────── */

.mobile-tab-bar {
  display: none;
}

.mobile-tab-panel {
  display: none;
}

/* ── Responsive ───────────────────────────── */

@media (max-width: 640px) {
  #header .header-subtitle {
    display: none;
  }
}

@media (max-width: 860px) {
  #app {
    grid-template-columns: 1fr;
    grid-template-rows: 56px 1fr;
    padding-bottom: var(--mobile-tab-bar-height);
  }

  #app.left-panel-collapsed,
  #app.right-panel-collapsed,
  #app.left-panel-collapsed.right-panel-collapsed {
    grid-template-columns: 1fr;
  }

  #header {
    grid-column: 1;
    grid-row: 1;
  }

  #left-panel,
  #right-panel,
  #resize-gutter-left,
  #resize-gutter-right,
  .panel-expand-tab,
  #settings-menu-wrap {
    display: none !important;
  }

  #center-panel {
    grid-column: 1;
    grid-row: 2;
  }

  #preview-container {
    max-width: 100%;
    border-radius: var(--radius-md);
  }

  #playback-bar {
    max-width: 100%;
    padding-bottom: 4px;
  }

  .playback-slide-name {
    max-width: 80px;
  }

  .mobile-tab-bar {
    display: flex;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 100;
    height: var(--mobile-tab-bar-height);
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-subtle);
    padding: 0 4px;
    padding-bottom: env(safe-area-inset-bottom, 0);
  }

  .mobile-tab {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    min-height: 44px;
    padding: 4px 2px;
    border: none;
    background: transparent;
    color: var(--text-muted);
    font-family: var(--font-ui);
    font-size: 9px;
    font-weight: 500;
    cursor: pointer;
    transition: color var(--transition);
  }

  .mobile-tab svg {
    width: 18px;
    height: 18px;
  }

  .mobile-tab.active {
    color: var(--accent);
  }

  #app.mobile-tab-slides #center-panel,
  #app.mobile-tab-edit #center-panel,
  #app.mobile-tab-style #center-panel,
  #app.mobile-tab-settings #center-panel {
    display: none;
  }

  .mobile-tab-panel {
    grid-column: 1;
    grid-row: 2;
    overflow-y: auto;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-subtle);
  }

  #app.mobile-tab-slides #mobile-tab-slides,
  #app.mobile-tab-edit #mobile-tab-edit,
  #app.mobile-tab-style #mobile-tab-style,
  #app.mobile-tab-settings #mobile-tab-settings {
    display: flex;
    flex-direction: column;
  }

  #mobile-tab-slides .slide-add-buttons,
  #mobile-tab-slides #slide-list-mobile-host,
  #mobile-tab-slides #left-export-section-mobile-host {
    flex-shrink: 0;
  }

  #mobile-tab-slides #slide-list-mobile-host {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
  }

  #mobile-tab-edit,
  #mobile-tab-style {
    padding: 0;
  }

  #mobile-tab-edit .panel-content,
  #mobile-tab-style .panel-content {
    overflow-y: visible;
  }

  #mobile-tab-settings {
    padding: 0;
  }
}

/* ── WebGL gate & toast ───────────────────── */

.app-blocked {
  box-sizing: border-box;
  max-width: 36rem;
  margin: 3rem auto;
  padding: 1.5rem 1.75rem;
  background: var(--bg-secondary, #1a1416);
  border: 1px solid var(--border, #2e2226);
  border-radius: var(--radius-md, 8px);
  color: var(--text-primary, #f4e8ec);
}

.app-blocked h1 {
  margin: 0 0 0.75rem;
  font-size: 1.35rem;
}

.app-blocked p {
  margin: 0;
  line-height: 1.55;
  color: var(--text-muted, #a8989e);
}

.app-toast {
  position: fixed;
  bottom: 1.25rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2000;
  max-width: min(90vw, 28rem);
  padding: 0.65rem 1rem;
  border-radius: var(--radius-sm, 6px);
  font-size: 0.9rem;
  line-height: 1.4;
  background: var(--bg-tertiary, #151012);
  border: 1px solid var(--border, #2e2226);
  color: var(--text-primary, #f4e8ec);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
}

.app-toast.app-toast-error {
  border-color: #7f1d1d;
  color: #fecaca;
}

/* ── Help modal ─────────────────────────────── */

.help-modal {
  position: fixed;
  inset: 0;
  z-index: 3000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.help-modal[hidden] {
  display: none !important;
}

.help-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
}

.help-modal-panel {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 32rem;
  max-height: min(85vh, 36rem);
  display: flex;
  flex-direction: column;
  background: var(--bg-secondary, #1a1416);
  border: 1px solid var(--border, #2e2226);
  border-radius: var(--radius-md, 8px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.45);
}

.help-modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border, #2e2226);
}

.help-modal-header h2 {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 600;
}

.help-modal-close {
  flex-shrink: 0;
  width: 2rem;
  height: 2rem;
  padding: 0;
  border: none;
  border-radius: var(--radius-sm, 6px);
  background: transparent;
  color: var(--text-muted, #a8989e);
  font-size: 1.35rem;
  line-height: 1;
  cursor: pointer;
}

.help-modal-close:hover {
  background: var(--bg-hover, #251c20);
  color: var(--text-primary, #f4e8ec);
}

.help-modal-body {
  padding: 1rem 1.1rem 1.25rem;
  overflow-y: auto;
  font-size: 0.875rem;
  line-height: 1.55;
  color: var(--text-muted, #a8989e);
}

.help-modal-contact {
  margin-bottom: 1.25rem;
  padding-bottom: 1.15rem;
  border-bottom: 1px solid var(--border, #2e2226);
}

.help-modal-contact > p {
  margin: 0 0 0.6rem;
  font-size: 0.8125rem;
}

.help-modal-email-btn {
  text-decoration: none;
  box-sizing: border-box;
}

.help-modal-body section {
  margin-bottom: 1rem;
}

.help-modal-body section:last-child {
  margin-bottom: 0;
}

.help-modal-body h3 {
  margin: 0 0 0.35rem;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-primary, #f4e8ec);
}

.help-modal-body code {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 0.82em;
  padding: 0.1em 0.35em;
  border-radius: 4px;
  background: var(--bg-tertiary, #151012);
}

.help-hint {
  margin: 0 0 0.5rem;
  font-size: 0.8rem;
  color: var(--text-muted, #a8989e);
  line-height: 1.45;
}

.custom-font-input {
  width: 100%;
  box-sizing: border-box;
  padding: 0.45rem 0.55rem;
  font-size: 0.85rem;
  border: 1px solid var(--border, #2e2226);
  border-radius: var(--radius-sm, 6px);
  background: var(--bg-tertiary, #151012);
  color: var(--text-primary, #f4e8ec);
}

.btn-block {
  width: 100%;
}

@media (prefers-reduced-motion: reduce) {
  .header-logo animate {
    animation: none !important;
  }

  #preview-container {
    box-shadow: var(--shadow-lg);
  }
}

/* ── Focus visible ──────────────────────────── */

:focus {
  outline: none;
}

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

.control-section-header:focus-visible {
  outline-offset: 4px;
}

input[type="range"]:focus-visible::-webkit-slider-thumb {
  box-shadow: 0 0 0 3px var(--accent-glow);
}

input[type="range"]:focus-visible::-moz-range-thumb {
  box-shadow: 0 0 0 3px var(--accent-glow);
}

/* ── Utility ──────────────────────────────── */

.hidden {
  display: none !important;
}

.text-center {
  text-align: center;
}

.mt-8 { margin-top: 8px; }
.mb-8 { margin-bottom: 8px; }