tutorial.css

:root {
  --color-bg-deep: #0d0d0f;
  --color-bg-primary: #141418;
  --color-bg-secondary: #1c1c21;
  --color-bg-tertiary: #25252b;
  --color-bg-hover: #2d2d35;
  --color-border: rgba(255, 255, 255, 0.07);
  --color-border-hover: rgba(255, 255, 255, 0.14);
  --color-text-primary: #f0f0f2;
  --color-text-secondary: #a0a0a8;
  --color-text-tertiary: #6b6b75;
  --color-accent: #10b981;
  --color-accent-hover: #059669;
  --color-accent-glow: rgba(16, 185, 129, 0.16);
  --color-accent-subtle: rgba(16, 185, 129, 0.1);
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.5);
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

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

html {
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: 'Noto Sans TC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background:
    linear-gradient(180deg, rgba(16, 185, 129, 0.04), transparent 34%),
    var(--color-bg-deep);
  color: var(--color-text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

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

button,
select,
input[type="range"],
input[type="color"] {
  cursor: pointer;
}

.tutorial-shell {
  display: grid;
  grid-template-columns: 248px minmax(0, 1fr);
  min-height: 100vh;
  padding-bottom: 86px;
}

.tutorial-rail {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: var(--spacing-xl) var(--spacing-lg);
  border-right: 1px solid var(--color-border);
  background: rgba(20, 20, 24, 0.82);
  backdrop-filter: blur(12px);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.brand-block {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.brand-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
}

.brand-subtitle {
  color: var(--color-text-tertiary);
  font-size: 0.88rem;
}

.step-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  padding: 0;
  margin: 0;
}

.step-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  color: var(--color-text-tertiary);
  padding: 10px;
  border-radius: var(--radius-md);
  cursor: pointer;
  outline: none;
  transition: background var(--transition-fast), color var(--transition-fast), box-shadow var(--transition-fast);
}

.step-item:hover,
.step-item:focus-visible {
  color: var(--color-text-primary);
  background: rgba(255, 255, 255, 0.04);
}

.step-item:focus-visible {
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}

.step-item.completed,
.step-item.active {
  color: var(--color-text-primary);
}

.step-item.active {
  background: var(--color-accent-subtle);
}

.step-number {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  font-size: 0.85rem;
  font-weight: 700;
  flex-shrink: 0;
}

.step-item.active .step-number,
.step-item.completed .step-number {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: white;
}

.step-label {
  font-weight: 600;
}

.rail-note {
  margin-top: auto;
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
  color: var(--color-text-tertiary);
  font-size: 0.86rem;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 6px var(--color-accent-subtle);
  flex-shrink: 0;
}

.tutorial-main {
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: var(--spacing-2xl) var(--spacing-xl);
}

.tutorial-step {
  display: none;
  animation: stepEnter 0.28s ease;
}

.tutorial-step.active {
  display: block;
}

.tutorial-step[data-step="5"] {
  animation: popupStepEnter 0.22s ease;
}

@keyframes stepEnter {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

.eyebrow {
  color: var(--color-accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.intro-layout,
.settings-layout,
.appearance-layout,
.interaction-layout,
.popup-guide-layout,
.completion-layout {
  display: grid;
  gap: var(--spacing-xl);
}

.intro-layout {
  min-height: calc(100vh - 180px);
  grid-template-columns: minmax(0, 0.9fr) minmax(420px, 1.1fr);
  align-items: center;
}

.intro-copy h1,
.step-header h2,
.completion-card h2 {
  margin: var(--spacing-sm) 0 var(--spacing-md);
  color: var(--color-text-primary);
  line-height: 1.15;
  letter-spacing: 0;
  overflow-wrap: anywhere;
}

.intro-copy h1 {
  font-size: clamp(2.3rem, 5vw, 4.8rem);
  max-width: 720px;
}

.intro-copy p,
.step-header p,
.completion-card p {
  color: var(--color-text-secondary);
  font-size: 1.02rem;
  max-width: 680px;
  margin: 0;
}

.intro-actions,
.completion-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
}

.signal-panel,
.settings-card,
.preview-card,
.instruction-card,
.popup-demo-card,
.completion-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
}

.signal-panel {
  padding: var(--spacing-lg);
}

.mini-player {
  min-height: 360px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: relative;
  background:
    linear-gradient(to top, rgba(0, 0, 0, 0.92), rgba(0, 0, 0, 0.18) 58%, rgba(0, 0, 0, 0.74)),
    linear-gradient(135deg, #30343d 0%, #575f6d 50%, #1b1f26 100%);
}

.mini-player-top {
  display: flex;
  gap: 7px;
  padding: var(--spacing-md);
}

.mini-player-top span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.22);
}

.mini-subtitles {
  position: absolute;
  left: 50%;
  bottom: 18%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  gap: 7px;
  align-items: center;
  width: 88%;
}

.mini-subtitle {
  display: inline-block;
  max-width: 100%;
  padding: 8px 16px;
  border-radius: 4px;
  background: rgba(0, 0, 0, 0.72);
  text-align: center;
  overflow-wrap: anywhere;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.85);
}

.mini-subtitle.primary {
  font-size: 1.85rem;
  font-weight: 700;
}

.mini-subtitle.secondary {
  color: #ffff00;
  font-size: 1.05rem;
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.metric-strip div {
  padding: var(--spacing-md);
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-md);
}

.metric-strip strong,
.completion-summary strong {
  display: block;
  color: var(--color-accent);
  font-size: 1rem;
}

.metric-strip span,
.completion-summary span {
  display: block;
  color: var(--color-text-tertiary);
  font-size: 0.82rem;
  margin-top: 2px;
}

.step-header {
  margin-bottom: var(--spacing-xl);
}

.step-header h2,
.completion-card h2 {
  font-size: clamp(2rem, 3.6vw, 3.25rem);
}

.settings-layout {
  grid-template-columns: minmax(360px, 0.9fr) minmax(420px, 1.1fr);
  align-items: start;
}

.appearance-layout {
  grid-template-columns: minmax(460px, 0.95fr) minmax(500px, 1.05fr);
  align-items: start;
}

.settings-card,
.preview-card,
.instruction-card,
.popup-demo-card,
.completion-card {
  padding: var(--spacing-lg);
}

.setting-group {
  margin-bottom: var(--spacing-xl);
}

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

.setting-label {
  display: block;
  color: var(--color-text-secondary);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  margin-bottom: var(--spacing-md);
  text-transform: uppercase;
}

.mode-toggle {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-md);
}

.mode-option {
  position: relative;
}

.mode-option input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.mode-box {
  min-height: 160px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-lg);
  background: var(--color-bg-tertiary);
  border: 2px solid transparent;
  border-radius: var(--radius-lg);
  text-align: center;
  transition: background var(--transition-normal), border-color var(--transition-normal);
}

.mode-option:hover .mode-box {
  background: var(--color-bg-hover);
  border-color: var(--color-border-hover);
}

.mode-option input:checked + .mode-box {
  background: var(--color-accent-subtle);
  border-color: var(--color-accent);
}

.mode-icon {
  width: 48px;
  height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xs);
}

.mode-icon svg,
.instruction-icon svg,
.tool-btn svg,
.btn svg,
.icon-button svg {
  width: 20px;
  height: 20px;
  stroke-width: 1.8;
}

.mode-option input:checked + .mode-box .mode-icon {
  background: var(--color-accent);
  color: white;
}

.mode-name {
  font-weight: 700;
  color: var(--color-text-primary);
}

.mode-desc {
  color: var(--color-text-tertiary);
  font-size: 0.84rem;
}

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

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

.select-wrapper,
.style-control {
  min-width: 0;
}

.select-wrapper {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.select-wrapper label,
.control-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-sm);
  color: var(--color-text-secondary);
  font-size: 0.88rem;
  margin-bottom: var(--spacing-sm);
}

.control-header strong {
  color: var(--color-accent);
  font-size: 0.85rem;
  font-weight: 700;
}

select,
textarea,
input[type="text"] {
  width: 100%;
  color: var(--color-text-primary);
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%23a0a0a8' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 40px;
}

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

select:focus,
textarea:focus,
input[type="text"]:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}

select:disabled,
input:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.preview-title {
  color: var(--color-text-secondary);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  margin-bottom: var(--spacing-md);
  text-transform: uppercase;
}

.subtitle-preview-screen {
  min-height: 290px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: relative;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  border: 1px solid var(--color-border);
  background: #101116;
}

.subtitle-preview-screen.large {
  min-height: 420px;
}

.preview-scene {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(to top, rgba(0, 0, 0, 0.78), rgba(0, 0, 0, 0.08) 58%, rgba(0, 0, 0, 0.45)),
    linear-gradient(135deg, #475569 0%, #1f2937 44%, #0f172a 100%);
}

.preview-scene::before,
.mock-player::before {
  content: "";
  position: absolute;
  inset: 12% 7% auto auto;
  width: 38%;
  height: 24%;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.09);
  transform: skewX(-9deg);
}

.preview-subtitle-stack {
  position: relative;
  z-index: 1;
  width: 100%;
  padding: 0 var(--spacing-md) var(--spacing-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.preview-subtitle {
  display: inline-block;
  max-width: 100%;
  padding: 5px 10px;
  border-radius: 4px;
  text-align: center;
  word-break: break-word;
  transition: color var(--transition-fast), background-color var(--transition-fast), font-size var(--transition-fast);
}

.sticky-preview {
  position: sticky;
  top: var(--spacing-xl);
}

.reset-btn {
  width: 100%;
  margin-top: var(--spacing-md);
}

.appearance-card {
  padding: 0;
  overflow: hidden;
}

.appearance-card > .setting-group,
.style-panel {
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--color-border);
}

.style-panel:last-child {
  border-bottom: none;
}

.style-panel.disabled {
  opacity: 0.52;
}

.style-panel-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.style-panel-header h3 {
  margin: 0;
  font-size: 1rem;
}

.style-panel-header span {
  color: var(--color-text-tertiary);
  font-size: 0.85rem;
}

.style-control.wide {
  grid-column: 1 / -1;
}

input[type="range"] {
  width: 100%;
  height: 6px;
  background: var(--color-bg-tertiary);
  border-radius: 3px;
  outline: none;
  appearance: none;
}

input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 2px 8px rgba(16, 185, 129, 0.35);
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-accent);
  border: none;
  box-shadow: 0 2px 8px rgba(16, 185, 129, 0.35);
}

.color-control {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: end;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm);
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-md);
}

.color-control .control-header {
  grid-column: 1;
  margin: 0;
}

input[type="color"] {
  grid-column: 2;
  grid-row: 1;
  width: 44px;
  height: 36px;
  padding: 0;
  border: none;
  background: transparent;
}

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

input[type="color"]::-webkit-color-swatch {
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.interaction-layout {
  grid-template-columns: minmax(520px, 1.2fr) minmax(320px, 0.8fr);
  align-items: stretch;
}

.mock-player {
  min-height: 520px;
  border-radius: var(--radius-xl);
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(to top, rgba(0, 0, 0, 0.88), rgba(0, 0, 0, 0.1) 55%, rgba(0, 0, 0, 0.74)),
    linear-gradient(135deg, #29313c, #4b5563 42%, #111827);
  box-shadow: var(--shadow-lg);
}

.mock-player-top,
.mock-controls {
  position: absolute;
  left: 0;
  right: 0;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  color: rgba(255, 255, 255, 0.86);
}

.mock-player-top {
  top: 0;
}

.mock-back {
  font-size: 2rem;
  line-height: 1;
}

.mock-play-button {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: rgba(255, 255, 255, 0.2);
}

.mock-play-button svg {
  width: 88px;
  height: 88px;
}

.mock-subtitle-zone {
  position: absolute;
  left: 50%;
  bottom: 21%;
  z-index: 3;
  transform: translateX(-50%);
  width: min(88%, 720px);
  display: flex;
  justify-content: center;
}

.mock-subtitle-stack {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  width: fit-content;
  max-width: 100%;
}

.subtitle-hover-guide {
  position: absolute;
  inset: -18px -28px;
  z-index: 1;
  border: 2px solid rgba(16, 185, 129, 0.88);
  border-radius: var(--radius-md);
  background: rgba(16, 185, 129, 0.06);
  box-shadow:
    0 0 0 1px rgba(209, 250, 229, 0.16),
    0 0 28px rgba(16, 185, 129, 0.28);
  pointer-events: none;
  opacity: 1;
  transform: scale(1);
  transition: opacity var(--transition-fast), transform var(--transition-fast);
  animation: subtitleGuideBreath 1.55s ease-in-out infinite;
}

.subtitle-hover-guide span {
  position: absolute;
  left: 50%;
  bottom: calc(100% + 10px);
  transform: translateX(-50%);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: max-content;
  max-width: min(420px, calc(100vw - 96px));
  padding: 7px 12px;
  border: 1px solid rgba(52, 211, 153, 0.34);
  border-radius: 999px;
  color: #d1fae5;
  background: rgba(6, 78, 59, 0.8);
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.32);
  font-size: 0.86rem;
  font-weight: 800;
  letter-spacing: 0;
  text-align: center;
  white-space: normal;
}

.subtitle-hover-guide span::after {
  content: '';
  position: absolute;
  left: 50%;
  top: calc(100% - 1px);
  width: 10px;
  height: 10px;
  border-right: 1px solid rgba(52, 211, 153, 0.34);
  border-bottom: 1px solid rgba(52, 211, 153, 0.34);
  background: rgba(6, 78, 59, 0.8);
  transform: translateX(-50%) rotate(45deg);
}

.mock-subtitle-zone:hover .subtitle-hover-guide,
.mock-subtitle-zone.hover-guide-dismissed .subtitle-hover-guide {
  opacity: 0;
  transform: scale(0.985);
  animation-play-state: paused;
}

@keyframes subtitleGuideBreath {
  0%,
  100% {
    box-shadow:
      0 0 0 1px rgba(209, 250, 229, 0.16),
      0 0 24px rgba(16, 185, 129, 0.24);
    transform: scale(1);
  }
  50% {
    box-shadow:
      0 0 0 6px rgba(16, 185, 129, 0.08),
      0 0 38px rgba(16, 185, 129, 0.38);
    transform: scale(1.025);
  }
}

.mock-primary-row {
  position: relative;
  z-index: 2;
  display: inline-block;
  max-width: 100%;
}

.mock-subtitle-stack > .mock-subtitle.secondary-preview {
  position: relative;
  z-index: 2;
}

.mock-toolbar {
  position: absolute;
  top: -55px;
  right: -58px;
  z-index: 2;
  display: flex;
  gap: var(--spacing-xs);
  padding: 6px;
  border-radius: var(--radius-md);
  background: rgba(13, 13, 15, 0.84);
  border: 1px solid rgba(255, 255, 255, 0.1);
  opacity: 0;
  transform: translateY(4px);
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.mock-subtitle-zone:hover .mock-toolbar,
.mock-toolbar.active {
  opacity: 1;
  transform: translateY(0);
}

.mock-subtitle {
  max-width: 100%;
  padding: 5px 10px;
  border-radius: 4px;
  background: rgba(0, 0, 0, 0.75);
  color: white;
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.9);
}

.tool-btn,
.icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: none;
  color: var(--color-text-primary);
  background: transparent;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.tool-btn {
  width: 38px;
  height: 34px;
}

.tool-btn:hover,
.icon-button:hover {
  background: var(--color-accent-subtle);
  color: var(--color-accent);
}

.mock-controls {
  bottom: 0;
  font-size: 0.86rem;
  color: rgba(255, 255, 255, 0.68);
}

.mock-timeline {
  flex: 1;
  height: 5px;
  border-radius: 99px;
  background: rgba(255, 255, 255, 0.18);
  overflow: hidden;
}

.mock-timeline span {
  display: block;
  width: 28%;
  height: 100%;
  background: var(--color-accent);
}

.instruction-card {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.instruction-item {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  border-radius: var(--radius-lg);
  background: var(--color-bg-tertiary);
}

.instruction-icon {
  width: 48px;
  height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background: var(--color-accent-subtle);
  color: var(--color-accent);
}

.instruction-item h3 {
  margin: 0 0 2px;
  font-size: 1rem;
}

.instruction-item p {
  margin: 0;
  color: var(--color-text-tertiary);
  font-size: 0.9rem;
}

.popup-guide-layout {
  grid-template-columns: minmax(620px, 1.35fr) minmax(300px, 0.65fr);
  align-items: start;
}

.popup-demo-card {
  position: relative;
  display: grid;
  justify-items: center;
  padding: var(--spacing-xl);
  overflow: visible;
}

.chrome-window-demo {
  position: relative;
  width: min(100%, 840px);
  min-height: 420px;
  overflow: visible;
  pointer-events: none;
  border: 1px solid var(--color-border-hover);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.08), transparent 44%),
    var(--color-bg-primary);
  box-shadow: var(--shadow-lg);
}

.toolbar-sketch-arrow {
  position: fixed;
  top: 6px;
  right: 129px;
  z-index: 45;
  width: clamp(520px, 36vw, 720px);
  height: 160px;
  color: #34d399;
  pointer-events: none;
  transition: opacity var(--transition-normal), transform var(--transition-normal);
}

.toolbar-sketch-arrow span {
  position: absolute;
  top: 104px;
  right: 72px;
  left: auto;
  z-index: 1;
  display: inline-flex;
  padding: 7px 12px;
  transform: rotate(-4deg);
  border: 1px solid rgba(52, 211, 153, 0.35);
  border-radius: 999px;
  color: #a7f3d0;
  background: rgba(6, 78, 59, 0.72);
  box-shadow: 0 0 24px rgba(16, 185, 129, 0.22);
  font-size: 0.9rem;
  font-weight: 800;
  letter-spacing: 0;
  white-space: nowrap;
}

.toolbar-sketch-arrow svg {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: visible;
  transform: rotate(-4deg);
  transform-origin: 92% 14%;
}

.toolbar-sketch-arrow path {
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.toolbar-sketch-arrow .arrow-shadow {
  stroke: rgba(5, 18, 16, 0.76);
  stroke-width: 9;
}

.toolbar-sketch-arrow .arrow-line,
.toolbar-sketch-arrow .arrow-head {
  stroke: currentColor;
  stroke-width: 5;
  filter: drop-shadow(0 0 10px rgba(52, 211, 153, 0.48));
}

.toolbar-sketch-arrow .arrow-head {
  fill: none;
}

.chrome-window-demo.popup-opened .toolbar-sketch-arrow {
  opacity: 0.18;
  transform: translateY(-4px);
}

.chrome-frame-top {
  display: flex;
  align-items: end;
  height: 48px;
  padding: 8px 14px 0;
  border-radius: calc(var(--radius-lg) - 1px) calc(var(--radius-lg) - 1px) 0 0;
  background: linear-gradient(180deg, rgba(39, 39, 42, 0.96), rgba(24, 24, 27, 0.98));
}

.chrome-tab {
  min-width: 174px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 0 14px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-bottom: none;
  border-radius: 10px 10px 0 0;
  color: var(--color-text-primary);
  background: rgba(255, 255, 255, 0.08);
  font-size: 0.88rem;
  font-weight: 700;
}

.chrome-tab-favicon {
  width: 18px;
  height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  color: white;
  background: #e50914;
  font-size: 0.72rem;
  font-weight: 900;
}

.chrome-tab-spacer {
  flex: 1;
}

.chrome-frame-toolbar {
  min-height: 56px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 9px 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  border-bottom: 1px solid var(--color-border);
  background: rgba(17, 24, 39, 0.88);
}

.chrome-nav-icons,
.chrome-frame-actions,
.chrome-menu-dots {
  display: inline-flex;
  align-items: center;
}

.chrome-nav-icons {
  gap: 8px;
  flex-shrink: 0;
}

.chrome-nav-icons span {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.chrome-address-mock {
  min-width: 0;
  flex: 1;
  padding: 10px 15px;
  overflow: hidden;
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: 999px;
  color: var(--color-text-secondary);
  background: rgba(3, 7, 18, 0.72);
  font-size: 0.88rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chrome-frame-actions {
  gap: 8px;
  flex-shrink: 0;
}

.chrome-star-icon,
.chrome-puzzle-target {
  width: 34px;
  height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
}

.chrome-star-icon svg,
.chrome-puzzle-target svg {
  width: 19px;
  height: 19px;
  stroke-width: 2;
}

.chrome-puzzle-target {
  color: #d1fae5;
  border: 1px solid rgba(52, 211, 153, 0.48);
  background: rgba(16, 185, 129, 0.18);
  box-shadow:
    0 0 0 4px rgba(16, 185, 129, 0.12),
    0 0 24px rgba(16, 185, 129, 0.34);
}

.chrome-window-demo:not(.popup-opened) .chrome-puzzle-target {
  animation: puzzlePulse 1.6s ease-in-out infinite;
}

@keyframes puzzlePulse {
  0%,
  100% {
    box-shadow:
      0 0 0 4px rgba(16, 185, 129, 0.12),
      0 0 24px rgba(16, 185, 129, 0.34);
  }

  50% {
    box-shadow:
      0 0 0 8px rgba(16, 185, 129, 0.2),
      0 0 34px rgba(16, 185, 129, 0.48);
  }
}

.chrome-menu-dots {
  width: 24px;
  justify-content: center;
  flex-direction: column;
  gap: 3px;
}

.chrome-menu-dots i {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--color-text-secondary);
}

.chrome-frame-viewport {
  position: relative;
  min-height: 316px;
  display: grid;
  place-items: center;
  overflow: hidden;
  border-radius: 0 0 calc(var(--radius-lg) - 1px) calc(var(--radius-lg) - 1px);
  background:
    radial-gradient(circle at 18% 14%, rgba(229, 9, 20, 0.16), transparent 28%),
    linear-gradient(135deg, rgba(10, 10, 10, 0.96), rgba(24, 24, 27, 0.92));
}

.chrome-frame-viewport::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(0deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: 0.24;
}

.popup-waiting-state,
.popup-guide-success {
  position: relative;
  z-index: 1;
  width: min(420px, calc(100% - 48px));
  display: grid;
  justify-items: center;
  gap: 10px;
  padding: var(--spacing-xl);
  text-align: center;
  transition: opacity var(--transition-normal), transform var(--transition-normal);
}

.popup-waiting-state h3,
.popup-guide-success h3 {
  margin: 0;
  color: var(--color-text-primary);
  font-size: 1.42rem;
}

.popup-waiting-state p,
.popup-guide-success p {
  margin: 0;
  color: var(--color-text-tertiary);
  font-size: 0.94rem;
  line-height: 1.7;
}

.waiting-orbit {
  width: 58px;
  height: 58px;
  border: 1px solid rgba(52, 211, 153, 0.26);
  border-radius: 50%;
  background:
    radial-gradient(circle, rgba(52, 211, 153, 0.52) 0 8px, transparent 9px),
    rgba(16, 185, 129, 0.08);
  box-shadow: 0 0 32px rgba(16, 185, 129, 0.22);
}

.popup-guide-success {
  position: absolute;
  opacity: 0;
  transform: translateY(18px);
}

.success-mark {
  width: 66px;
  height: 66px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: #d1fae5;
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.95), rgba(5, 150, 105, 0.9));
  box-shadow: 0 18px 44px rgba(16, 185, 129, 0.34);
}

.success-mark svg {
  width: 34px;
  height: 34px;
  stroke-width: 3;
}

.chrome-window-demo.popup-opened .popup-waiting-state {
  opacity: 0;
  transform: translateY(-16px);
}

.chrome-window-demo.popup-opened .popup-guide-success {
  opacity: 1;
  transform: translateY(0);
}

.popup-guide-card {
  position: sticky;
  top: var(--spacing-xl);
}

.completion-layout {
  min-height: calc(100vh - 190px);
  place-items: center;
}

.completion-card {
  width: min(760px, 100%);
  padding: var(--spacing-2xl);
  text-align: center;
}

.completion-card p {
  margin: 0 auto;
}

.completion-summary {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
}

.completion-summary div {
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  background: var(--color-bg-tertiary);
}

.completion-community {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.community-button {
  min-height: 54px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  background: var(--color-bg-tertiary);
  font-weight: 800;
  text-decoration: none;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.community-button:hover,
.community-button:focus-visible {
  border-color: rgba(16, 185, 129, 0.34);
  color: #d1fae5;
  background: rgba(16, 185, 129, 0.12);
  box-shadow: 0 0 0 4px var(--color-accent-glow);
  transform: translateY(-1px);
  outline: none;
}

.community-button svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  fill: currentColor;
}

.completion-actions {
  justify-content: center;
}

.tutorial-footer {
  position: fixed;
  left: 248px;
  right: 0;
  bottom: 0;
  z-index: 20;
  min-height: 76px;
  padding: var(--spacing-md) var(--spacing-xl);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-md);
  border-top: 1px solid var(--color-border);
  background: rgba(13, 13, 15, 0.9);
  backdrop-filter: blur(14px);
}

.footer-actions {
  display: flex;
  gap: var(--spacing-md);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  padding: 11px 18px;
  font-weight: 700;
  color: var(--color-text-primary);
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast), box-shadow var(--transition-fast);
}

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

.btn-primary:hover {
  background: var(--color-accent-hover);
  box-shadow: 0 0 0 4px var(--color-accent-glow);
}

.btn-secondary {
  background: var(--color-bg-tertiary);
  border-color: var(--color-border);
}

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

.btn-ghost {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-text-secondary);
}

.btn-ghost:hover {
  color: var(--color-text-primary);
  background: var(--color-bg-tertiary);
}

.btn:disabled {
  opacity: 0.48;
  cursor: not-allowed;
}

.submit-overlay {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: none;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-lg);
  background: rgba(0, 0, 0, 0.72);
}

.submit-overlay.show {
  display: flex;
}

.submit-dialog {
  width: min(560px, 100%);
  max-height: min(760px, 92vh);
  overflow: auto;
  padding: var(--spacing-lg);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-hover);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
}

.dialog-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.dialog-header h3 {
  margin: 4px 0 0;
  font-size: 1.35rem;
}

.icon-button {
  width: 38px;
  height: 38px;
}

.form-grid {
  display: grid;
  gap: var(--spacing-md);
}

.form-grid label {
  display: grid;
  gap: var(--spacing-sm);
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

textarea {
  min-height: 96px;
  resize: vertical;
}

input[readonly] {
  color: var(--color-text-secondary);
}

.dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.toast {
  position: fixed;
  top: var(--spacing-lg);
  left: 50%;
  z-index: 60;
  transform: translateX(-50%) translateY(-18px);
  opacity: 0;
  pointer-events: none;
  padding: 10px 16px;
  border-radius: var(--radius-md);
  color: white;
  background: var(--color-accent);
  box-shadow: 0 8px 24px rgba(16, 185, 129, 0.3);
  transition: opacity var(--transition-normal), transform var(--transition-normal);
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

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

  .tutorial-rail {
    position: static;
    height: auto;
    width: 100%;
    min-width: 0;
    overflow: hidden;
    padding: var(--spacing-md) var(--spacing-lg);
    border-right: none;
    border-bottom: 1px solid var(--color-border);
  }

  .step-list {
    flex-direction: row;
    overflow-x: auto;
    min-width: 0;
  }

  .rail-note {
    display: none;
  }

  .tutorial-footer {
    left: 0;
  }

  .intro-layout,
  .settings-layout,
  .appearance-layout,
  .interaction-layout,
  .popup-guide-layout {
    grid-template-columns: 1fr;
  }

  .sticky-preview,
  .popup-guide-card {
    position: static;
  }

  .popup-demo-card {
    margin-top: var(--spacing-md);
  }

  .toolbar-sketch-arrow {
    top: -10px;
    right: 36px;
    width: clamp(430px, 42vw, 560px);
    height: 150px;
    transform: none;
    transform-origin: top right;
  }

  .toolbar-sketch-arrow span {
    top: 94px;
    right: 66px;
  }

  .chrome-window-demo {
    min-height: 350px;
  }

  .chrome-frame-viewport {
    min-height: 246px;
    place-items: start center;
  }

  .popup-waiting-state,
  .popup-guide-success {
    padding: var(--spacing-md);
  }

  .popup-guide-success {
    top: 8px;
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    justify-items: start;
    gap: 6px 12px;
    text-align: left;
  }

  .waiting-orbit {
    width: 42px;
    height: 42px;
    background:
      radial-gradient(circle, rgba(52, 211, 153, 0.52) 0 6px, transparent 7px),
      rgba(16, 185, 129, 0.08);
  }

  .success-mark {
    grid-row: 1 / 3;
    width: 48px;
    height: 48px;
  }

  .success-mark svg {
    width: 26px;
    height: 26px;
  }

  .popup-guide-success p {
    font-size: 0.84rem;
    line-height: 1.5;
  }

  .popup-waiting-state h3,
  .popup-guide-success h3 {
    font-size: 1.22rem;
  }
}

@media (max-width: 760px) {
  body {
    width: 100%;
  }

  .tutorial-main {
    padding: var(--spacing-lg) var(--spacing-md);
    max-width: 100vw;
  }

  .tutorial-shell {
    padding-bottom: 132px;
  }

  .brand-block {
    justify-content: center;
  }

  .step-list {
    justify-content: center;
    width: 100%;
    max-width: 100%;
  }

  .step-item {
    min-width: auto;
    padding: 8px;
    flex: 0 0 auto;
  }

  .step-label {
    display: none;
  }

  .intro-copy h1,
  .step-header h2,
  .completion-card h2 {
    font-size: 2rem;
  }

  .signal-panel,
  .settings-card,
  .preview-card,
  .instruction-card,
  .popup-demo-card,
  .completion-card {
    padding: var(--spacing-md);
  }

  .mini-player {
    min-height: 300px;
  }

  .mini-subtitle.primary {
    font-size: 1.45rem;
  }

  .mini-subtitle.secondary {
    font-size: 0.95rem;
  }

  .mode-toggle,
  .language-grid,
  .style-grid,
  .style-grid.compact,
  .completion-community,
  .completion-summary,
  .metric-strip {
    grid-template-columns: 1fr;
  }

  .mode-box {
    min-height: 126px;
  }

  .subtitle-preview-screen.large,
  .mock-player {
    min-height: 360px;
  }

  .chrome-window-demo {
    min-height: 340px;
  }

  .toolbar-sketch-arrow {
    position: relative;
    top: auto;
    right: auto;
    width: min(100%, 360px);
    height: 118px;
    margin: -8px 0 var(--spacing-md);
    transform: none;
  }

  .toolbar-sketch-arrow span {
    top: 0;
    left: 0;
    max-width: 100%;
    white-space: normal;
  }

  .toolbar-sketch-arrow svg {
    top: 6px;
    transform: scale(0.82) rotate(-4deg);
    transform-origin: left top;
  }

  .chrome-frame-top {
    height: 44px;
    padding-inline: 10px;
  }

  .chrome-tab {
    min-width: 132px;
  }

  .chrome-frame-toolbar {
    gap: 8px;
    padding: 8px 10px;
  }

  .chrome-nav-icons span,
  .chrome-star-icon {
    display: none;
  }

  .chrome-address-mock {
    padding: 9px 12px;
    font-size: 0.76rem;
  }

  .chrome-puzzle-target {
    width: 32px;
    height: 32px;
  }

  .chrome-frame-viewport {
    min-height: 236px;
  }

  .popup-waiting-state,
  .popup-guide-success {
    width: calc(100% - 28px);
    padding: var(--spacing-lg) var(--spacing-md);
  }

  .mock-subtitle {
    font-size: 1.35rem;
  }

  .tutorial-footer {
    align-items: stretch;
    flex-direction: column-reverse;
    padding: var(--spacing-md);
  }

  .footer-actions {
    width: 100%;
  }

  .footer-actions .btn,
  #skipTutorialBtn {
    flex: 1;
  }

  .dialog-actions {
    flex-direction: column-reverse;
  }

  .dialog-actions .btn {
    width: 100%;
  }
}