OSGKeyboard/docs/assets/site.css

:root {
  color-scheme: light dark;
  --canvas: #eef2f6;
  --surface: #ffffff;
  --surface-soft: #f7f9fb;
  --surface-strong: #e5eaf0;
  --ink: #111416;
  --ink-secondary: #5f676e;
  --ink-tertiary: #8b949c;
  --line: rgba(17, 20, 22, 0.1);
  --line-strong: rgba(17, 20, 22, 0.18);
  --accent: #2d8a57;
  --accent-strong: #237247;
  --accent-soft: rgba(45, 138, 87, 0.1);
  --inverse: #f4f7f5;
  --inverse-secondary: #aab2ad;
  --inverse-line: rgba(255, 255, 255, 0.12);
  --content: min(1200px, calc(100vw - 64px));
  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 16px;
}

html[data-theme="dark"] {
  --canvas: #0c0e0f;
  --surface: #191c1e;
  --surface-soft: #222628;
  --surface-strong: #2b3033;
  --ink: #f2f4f3;
  --ink-secondary: #aab0ac;
  --ink-tertiary: #737a75;
  --line: rgba(255, 255, 255, 0.09);
  --line-strong: rgba(255, 255, 255, 0.16);
  --accent: #6fbd8a;
  --accent-strong: #82ca99;
  --accent-soft: rgba(111, 189, 138, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 96px;
  background: var(--canvas);
}

body {
  margin: 0;
  overflow-x: hidden;
  background: var(--canvas);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC",
    "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

html[data-lang="en"] body {
  font-family: "Outfit", -apple-system, BlinkMacSystemFont, "SF Pro Text",
    "Helvetica Neue", Arial, sans-serif;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  color: inherit;
  font: inherit;
}

img {
  display: block;
  max-width: 100%;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  text-wrap: balance;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  padding: 9px 14px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--surface);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-nav {
  position: fixed;
  z-index: 50;
  top: 18px;
  right: 0;
  left: 0;
  width: var(--content);
  margin: auto;
}

.nav-shell {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  min-height: 56px;
  padding: 7px 8px 7px 15px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: color-mix(in srgb, var(--surface) 82%, transparent);
  box-shadow: 0 10px 32px rgba(17, 20, 22, 0.04);
  backdrop-filter: blur(22px) saturate(140%);
  -webkit-backdrop-filter: blur(22px) saturate(140%);
}

.brand {
  display: inline-flex;
  gap: 10px;
  align-items: center;
  justify-self: start;
  font-size: 0.94rem;
  font-weight: 700;
  letter-spacing: -0.015em;
}

.brand img {
  width: 30px;
  height: 30px;
  border-radius: 9px;
}

.nav-links,
.nav-actions {
  display: flex;
  align-items: center;
}

.nav-links {
  gap: 30px;
  color: var(--ink-secondary);
  font-size: 0.84rem;
  font-weight: 550;
}

.nav-actions {
  gap: 4px;
  justify-self: end;
}

.nav-links a,
.footer-links a {
  transition: color 160ms ease;
}

.nav-links a:hover,
.nav-links a:focus-visible,
.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--ink);
}

.icon-button,
.language-button {
  display: inline-grid;
  min-width: 40px;
  height: 40px;
  padding: 0 11px;
  border: 0;
  border-radius: 11px;
  background: transparent;
  cursor: pointer;
  place-items: center;
}

.icon-button:hover,
.language-button:hover,
.icon-button:focus-visible,
.language-button:focus-visible {
  background: var(--surface-strong);
}

.language-button {
  font-size: 0.76rem;
  font-weight: 700;
}

.icon-button.mobile-menu-button,
.mobile-nav {
  display: none;
}

.mobile-nav {
  gap: 4px;
  margin-top: 8px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  box-shadow: 0 14px 34px rgba(17, 20, 22, 0.08);
  backdrop-filter: blur(22px);
  -webkit-backdrop-filter: blur(22px);
}

.mobile-nav a {
  padding: 11px 14px;
  border-radius: 10px;
  color: var(--ink-secondary);
  font-size: 0.84rem;
  font-weight: 650;
  text-align: center;
}

.mobile-nav a:hover,
.mobile-nav a:focus-visible {
  background: var(--surface-strong);
  color: var(--ink);
}

.material-symbols-rounded {
  display: inline-grid;
  width: 1.35em;
  height: 1.35em;
  font-size: 0 !important;
  line-height: 1;
  place-items: center;
}

.material-symbols-rounded::before {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", sans-serif;
  line-height: 1;
}

.mobile-menu-button .material-symbols-rounded,
#themeToggle .material-symbols-rounded {
  display: none;
}

.mobile-menu-button::before {
  width: 17px;
  height: 12px;
  border-top: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  content: "";
}

.mobile-menu-button[aria-expanded="true"]::before {
  width: auto;
  height: auto;
  border: 0;
  content: "×";
  font-size: 1.4rem;
  font-weight: 300;
}

#themeToggle::before {
  content: "◐";
  font-size: 1.05rem;
}

html[data-theme="dark"] #themeToggle::before {
  content: "☀";
  font-size: 1rem;
}

.scroll-cue .material-symbols-rounded::before,
.stage-arrow::before {
  content: "↓";
  font-size: 1rem;
}

.stage-arrow,
.clipboard-source > .material-symbols-rounded,
.correction-chip .material-symbols-rounded,
.outline-action .material-symbols-rounded {
  width: 22px;
  height: 22px;
}

.assistant-tabs > .material-symbols-rounded::before {
  content: "•••";
  font-size: 0.72rem;
  letter-spacing: 0.08em;
}

.round-control:first-child .material-symbols-rounded::before {
  content: "↶";
  font-size: 1.15rem;
}

.round-control:last-child .material-symbols-rounded::before {
  content: "↑";
  font-size: 1.05rem;
}

.mic-control .material-symbols-rounded::before {
  content: "●";
  font-size: 0.72rem;
}

.gesture-grid .material-symbols-rounded,
.skill-actions .material-symbols-rounded {
  display: none;
}

.clipboard-source > .material-symbols-rounded::before {
  content: "⧉";
  font-size: 1.35rem;
}

.correction-chip .material-symbols-rounded::before {
  content: "✓";
  font-size: 0.95rem;
}

.privacy-proof > div > .material-symbols-rounded::before {
  content: "◈";
  font-size: 1.55rem;
}

.ios-symbol .material-symbols-rounded::before {
  content: "⌨";
  font-size: 2.25rem;
}

.ios-symbol .material-symbols-rounded {
  width: 46px;
  height: 46px;
}

.outline-action .material-symbols-rounded::before {
  content: "⌘";
  font-size: 1rem;
}

.hero {
  position: relative;
  display: grid;
  min-height: 100svh;
  padding: 132px 0 92px;
  overflow: hidden;
  place-items: center;
}

.hero-orb {
  position: absolute;
  top: 42%;
  left: 50%;
  width: min(760px, 84vw);
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(
    circle,
    color-mix(in srgb, var(--accent) 12%, transparent) 0%,
    color-mix(in srgb, #7ea7d8 8%, transparent) 38%,
    transparent 70%
  );
  filter: blur(8px);
  pointer-events: none;
  transform: translate(-50%, -50%);
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  width: var(--content);
  max-width: 920px;
  flex-direction: column;
  text-align: center;
}

.launch-pill {
  display: inline-flex;
  gap: 9px;
  align-items: center;
  margin-bottom: clamp(54px, 8vh, 86px);
  padding: 9px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--surface) 72%, transparent);
  color: var(--ink-secondary);
  font-size: 0.76rem;
  font-weight: 650;
  box-shadow: 0 10px 34px rgba(17, 20, 22, 0.05);
}

.launch-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-soft);
}

.hero h1 {
  max-width: 900px;
  margin-bottom: 25px;
  font-size: clamp(3.6rem, 5.6vw, 4.5rem);
  font-weight: 700;
  letter-spacing: -0.055em;
  line-height: 1.02;
}

.hero h1 > span {
  display: block;
}

html[data-lang="zh"] .hero h1 {
  max-width: 840px;
  font-size: clamp(3.25rem, 5vw, 4rem);
  letter-spacing: -0.035em;
  line-height: 1.12;
}

.hero-muted {
  color: var(--ink-tertiary);
}

.hero-copy {
  max-width: 700px;
  margin-bottom: 29px;
  color: var(--ink-secondary);
  font-size: clamp(1.02rem, 1.5vw, 1.18rem);
  line-height: 1.75;
}

.hero-actions,
.download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
}

.store-badge {
  display: inline-flex;
  transition: opacity 160ms ease, transform 160ms ease;
}

.store-badge img {
  width: auto;
  height: 48px;
}

.store-badge:hover,
.store-badge:focus-visible {
  opacity: 0.86;
  transform: translateY(-1px);
}

.text-action {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  padding: 0 15px;
  color: var(--ink-secondary);
  font-size: 0.86rem;
  font-weight: 650;
}

.text-action::after {
  margin-left: 7px;
  content: "↗";
}

.text-action:hover,
.text-action:focus-visible {
  color: var(--ink);
}

.hero-note {
  margin: 18px 0 0;
  color: var(--ink-tertiary);
  font-size: 0.74rem;
}

.scroll-cue {
  position: absolute;
  bottom: 26px;
  left: 50%;
  display: inline-flex;
  gap: 8px;
  align-items: center;
  color: var(--ink-tertiary);
  font-size: 0.72rem;
  transform: translateX(-50%);
}

.scroll-cue .material-symbols-rounded {
  font-size: 17px;
}

.section {
  padding: clamp(96px, 10vw, 150px) 0;
}

.section-inner {
  width: var(--content);
  margin: auto;
}

.product-section {
  background: var(--surface);
}

.eyebrow {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  margin: 0 0 15px;
  color: var(--ink-secondary);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

html[data-lang="zh"] .eyebrow {
  letter-spacing: 0.06em;
  text-transform: none;
}

.eyebrow::before {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  content: "";
}

.center-heading {
  max-width: 830px;
  margin: 0 auto clamp(52px, 7vw, 84px);
  text-align: center;
}

.center-heading.compact {
  margin-bottom: clamp(42px, 6vw, 68px);
}

.center-heading h2,
.scene-copy h2,
.split-heading h2,
.faq-layout h2 {
  margin-bottom: 18px;
  font-size: clamp(2.55rem, 4.2vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.05em;
  line-height: 1.06;
}

html[data-lang="zh"] .center-heading h2,
html[data-lang="zh"] .scene-copy h2,
html[data-lang="zh"] .split-heading h2,
html[data-lang="zh"] .faq-layout h2 {
  font-size: clamp(2.25rem, 3.8vw, 3.15rem);
  letter-spacing: -0.03em;
  line-height: 1.14;
}

.faq-layout h2 {
  font-size: clamp(2.3rem, 3.5vw, 3rem);
}

html[data-lang="zh"] .faq-layout h2 {
  font-size: clamp(2.1rem, 3vw, 2.65rem);
}

.center-heading > p:last-child,
.scene-copy > p,
.split-heading > p {
  color: var(--ink-secondary);
  font-size: clamp(1rem, 1.4vw, 1.12rem);
  line-height: 1.75;
}

.center-heading > p:last-child {
  max-width: 700px;
  margin: auto;
}

.product-stage {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background: var(--surface-soft);
  box-shadow: 0 30px 80px rgba(30, 42, 52, 0.08);
}

.stage-bar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  min-height: 54px;
  padding: 0 18px;
  border-bottom: 1px solid var(--line);
  color: var(--ink-tertiary);
  font-size: 0.72rem;
}

.stage-dots {
  display: flex;
  gap: 6px;
}

.stage-dots i {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--surface-strong);
}

.stage-status {
  justify-self: end;
}

.stage-content {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(360px, 0.95fr);
  min-height: 560px;
}

.conversation {
  display: flex;
  justify-content: center;
  padding: clamp(42px, 6vw, 76px);
  border-right: 1px solid var(--line);
  flex-direction: column;
}

.conversation-label,
.typing-label,
.platform-label {
  color: var(--ink-tertiary);
  font-size: 0.71rem;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.message-bubble {
  align-self: flex-start;
  max-width: 510px;
  margin: 12px 0 24px;
  padding: 18px 20px;
  border-radius: 18px 18px 18px 5px;
  background: var(--ink);
  color: var(--surface);
  font-size: clamp(1.1rem, 1.8vw, 1.45rem);
  font-weight: 600;
  line-height: 1.5;
}

html[data-theme="dark"] .message-bubble {
  background: #f1f4f2;
  color: #151817;
}

.insert-preview {
  position: relative;
  max-width: 520px;
  padding: 22px 24px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
}

.preview-kicker {
  color: var(--accent);
  font-size: 0.71rem;
  font-weight: 700;
}

.insert-preview p {
  margin: 9px 0 0;
  font-size: clamp(1.05rem, 1.5vw, 1.3rem);
  font-weight: 550;
  line-height: 1.55;
}

.text-cursor {
  display: inline-block;
  width: 2px;
  height: 1.1em;
  margin-left: 3px;
  background: var(--accent);
  vertical-align: -0.1em;
}

.insert-preview .text-cursor {
  position: absolute;
  right: 22px;
  bottom: 24px;
}

.keyboard-demo {
  display: flex;
  min-width: 0;
  background: var(--surface-strong);
  flex-direction: column;
}

.assistant-tabs {
  display: grid;
  grid-template-columns: 46px repeat(3, auto) 1fr;
  gap: 8px;
  align-items: center;
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
}

.assistant-logo {
  display: grid;
  width: 36px;
  height: 36px;
  border-radius: 11px;
  background: var(--accent);
  color: #fff;
  font-size: 0.66rem;
  font-weight: 800;
  place-items: center;
}

.assistant-tab {
  padding: 6px 9px;
  border-radius: 999px;
  color: var(--ink-tertiary);
  font-size: 0.72rem;
  font-weight: 650;
}

.assistant-tab.active {
  background: var(--surface);
  color: var(--ink);
}

.assistant-tabs > .material-symbols-rounded {
  justify-self: end;
  color: var(--ink-tertiary);
}

.keyboard-keys {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 7px;
  padding: clamp(42px, 6vw, 80px) 18px 20px;
}

.keyboard-keys span {
  display: grid;
  min-width: 0;
  height: 42px;
  border-bottom: 2px solid var(--line-strong);
  color: var(--ink-secondary);
  font-size: 0.75rem;
  place-items: center;
}

.keyboard-keys span:nth-child(n + 11) {
  transform: translateX(50%);
}

.assistant-controls {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  margin-top: auto;
  padding: 22px 24px 26px;
  border-top: 1px solid var(--line);
}

.round-control,
.mic-control {
  display: grid;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--surface);
  color: var(--ink-secondary);
  place-items: center;
}

.round-control:last-child {
  justify-self: end;
}

.mic-control {
  width: 58px;
  height: 58px;
  background: var(--accent);
  color: #fff;
  box-shadow: 0 10px 24px color-mix(in srgb, var(--accent) 26%, transparent);
}

.gesture-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin-top: 28px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.gesture-grid article {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 5px 12px;
  min-height: 140px;
  padding: 28px 28px 25px 0;
  border-right: 1px solid var(--line);
}

.gesture-grid article:not(:first-child) {
  padding-left: 28px;
}

.gesture-grid article:last-child {
  border-right: 0;
}

.gesture-number {
  color: var(--ink-tertiary);
  font-size: 0.68rem;
  font-weight: 700;
}

.gesture-grid .material-symbols-rounded {
  color: var(--ink-secondary);
  font-size: 21px;
}

.gesture-grid h3,
.gesture-grid p {
  grid-column: 2;
}

.gesture-grid h3 {
  align-self: end;
  margin: 0;
  font-size: 1rem;
}

.gesture-grid p {
  margin: 0;
  color: var(--ink-secondary);
  font-size: 0.82rem;
}

.scene-section {
  background: var(--canvas);
}

.scene-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(520px, 1.2fr);
  gap: clamp(64px, 9vw, 124px);
  align-items: center;
}

.scene-copy {
  max-width: 510px;
}

.quiet-list {
  display: grid;
  gap: 12px;
  margin: 27px 0 0;
  padding: 0;
  color: var(--ink-secondary);
  font-size: 0.9rem;
  list-style: none;
}

.quiet-list li {
  position: relative;
  padding-left: 19px;
}

.quiet-list li::before {
  position: absolute;
  top: 0.65em;
  left: 0;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  content: "";
}

.voice-stage {
  padding: clamp(28px, 5vw, 52px);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background: var(--surface);
  box-shadow: 0 26px 70px rgba(30, 42, 52, 0.07);
}

.voice-meta,
.voice-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--ink-tertiary);
  font-size: 0.74rem;
}

.live-indicator {
  display: inline-flex;
  gap: 7px;
  align-items: center;
  color: var(--accent);
  font-weight: 650;
}

.live-indicator i {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
}

.transcript-card {
  display: flex;
  min-height: 230px;
  justify-content: center;
  padding: 54px 0 40px;
  flex-direction: column;
}

.transcript-card span,
.transcript-card strong {
  display: block;
  font-size: clamp(1.7rem, 3.2vw, 2.7rem);
  letter-spacing: -0.04em;
  line-height: 1.32;
}

html[data-lang="zh"] .transcript-card span,
html[data-lang="zh"] .transcript-card strong {
  font-size: clamp(1.6rem, 2.8vw, 2.35rem);
  letter-spacing: -0.025em;
}

.transcript-card span {
  color: var(--ink-tertiary);
}

.waveform {
  display: flex;
  gap: 7px;
  align-items: center;
  height: 66px;
  margin-bottom: 25px;
}

.waveform i {
  width: 4px;
  height: 22%;
  border-radius: 999px;
  background: var(--accent);
  opacity: 0.65;
  animation: waveform 1.8s ease-in-out infinite;
}

.waveform i:nth-child(2n) { height: 58%; animation-delay: -0.4s; }
.waveform i:nth-child(3n) { height: 86%; animation-delay: -0.9s; }
.waveform i:nth-child(5n) { height: 42%; animation-delay: -1.2s; }
.waveform i:nth-child(7n) { height: 100%; animation-delay: -0.2s; }

@keyframes waveform {
  0%,
  100% { transform: scaleY(0.7); }
  50% { transform: scaleY(1); }
}

.typing-section {
  background: var(--surface);
}

.typing-stories {
  display: grid;
  gap: 22px;
}

.typing-story {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(340px, 0.95fr);
  min-height: 460px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background: var(--surface-soft);
}

.typing-story.reverse .typing-visual {
  order: 2;
  border-right: 0;
  border-left: 1px solid var(--line);
}

.typing-visual {
  display: flex;
  justify-content: center;
  padding: clamp(36px, 6vw, 70px);
  border-right: 1px solid var(--line);
  flex-direction: column;
}

.composition-row {
  display: flex;
  align-items: center;
  min-height: 86px;
  font-size: clamp(2rem, 4vw, 3.4rem);
  letter-spacing: -0.04em;
}

.candidate-row,
.suggestion-row {
  display: flex;
  gap: 8px;
  margin-bottom: 42px;
  overflow: hidden;
}

.candidate-row span,
.suggestion-row span {
  flex: 0 0 auto;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--ink-secondary);
  font-size: 0.82rem;
}

.candidate-row .selected,
.suggestion-row .selected {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}

.mini-keyboard {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 7px;
}

.mini-keyboard span {
  display: grid;
  min-width: 0;
  height: 42px;
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink-secondary);
  font-size: 0.72rem;
  box-shadow: 0 1px 0 var(--line-strong);
  place-items: center;
}

.story-copy {
  display: flex;
  justify-content: center;
  padding: clamp(38px, 6vw, 70px);
  flex-direction: column;
}

.story-index {
  margin-bottom: auto;
  color: var(--ink-tertiary);
  font-size: 0.7rem;
  font-weight: 700;
}

.story-copy h3 {
  margin: 72px 0 14px;
  font-size: clamp(1.85rem, 3vw, 2.65rem);
  letter-spacing: -0.04em;
  line-height: 1.15;
}

html[data-lang="zh"] .story-copy h3 {
  font-size: clamp(1.7rem, 2.7vw, 2.3rem);
  letter-spacing: -0.025em;
}

.story-copy p {
  margin-bottom: 0;
  color: var(--ink-secondary);
  line-height: 1.75;
}

.english-visual {
  gap: 28px;
}

.english-line {
  position: relative;
  padding-bottom: 13px;
  border-bottom: 1px solid var(--line-strong);
  font-size: clamp(1.7rem, 3.5vw, 3rem);
  letter-spacing: -0.04em;
}

.correction-mark {
  position: absolute;
  right: 0;
  bottom: 6px;
  width: 25%;
  height: 3px;
  border-radius: 999px;
  background: #d26a5d;
}

.correction-chip {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  align-self: flex-start;
  padding: 9px 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  color: var(--accent);
  font-size: 0.86rem;
  font-weight: 650;
}

.correction-chip .material-symbols-rounded {
  font-size: 19px;
}

.skills-section {
  background: var(--canvas);
}

.skills-layout {
  grid-template-columns: minmax(520px, 1.15fr) minmax(0, 0.85fr);
}

.skills-stage {
  display: flex;
  min-height: 500px;
  justify-content: center;
  padding: clamp(30px, 5vw, 58px);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background: var(--surface);
  box-shadow: 0 26px 70px rgba(30, 42, 52, 0.07);
  flex-direction: column;
}

.clipboard-source {
  display: flex;
  gap: 16px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface-soft);
}

.clipboard-source > .material-symbols-rounded {
  color: var(--ink-tertiary);
}

.clipboard-source small {
  color: var(--ink-tertiary);
}

.clipboard-source p {
  margin: 5px 0 0;
  font-size: 1.02rem;
  line-height: 1.55;
}

.stage-arrow {
  align-self: center;
  margin: 25px 0;
  color: var(--ink-tertiary);
}

.skill-actions {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.skill-actions > span {
  display: flex;
  gap: 8px;
  align-items: center;
  min-height: 54px;
  padding: 0 13px;
  border: 1px solid var(--line);
  border-radius: 14px;
  color: var(--ink-secondary);
  font-size: 0.82rem;
  font-weight: 650;
}

.skill-actions > span.primary {
  border-color: color-mix(in srgb, var(--accent) 42%, var(--line));
  background: var(--accent-soft);
  color: var(--accent);
}

.skill-actions .material-symbols-rounded {
  font-size: 19px;
}

.styles-strip {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(400px, 1.1fr);
  gap: 64px;
  align-items: end;
  margin-top: clamp(80px, 10vw, 130px);
  padding-top: 42px;
  border-top: 1px solid var(--line);
}

.styles-strip h3 {
  max-width: 560px;
  margin: 0;
  font-size: clamp(2rem, 3.5vw, 3rem);
  letter-spacing: -0.045em;
  line-height: 1.15;
}

html[data-lang="zh"] .styles-strip h3 {
  font-size: clamp(1.9rem, 3vw, 2.6rem);
  letter-spacing: -0.025em;
}

.style-options {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

.style-options span {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
  color: var(--ink-secondary);
  font-size: 0.84rem;
  font-weight: 650;
}

.style-options span.selected {
  border-color: var(--accent);
  color: var(--ink);
}

.privacy-section {
  --section-ink: var(--ink);
  --section-secondary: var(--ink-secondary);
  --section-line: var(--line);
  background: #e5ebe8;
  color: var(--section-ink);
}

html[data-theme="dark"] .privacy-section {
  --section-ink: var(--inverse);
  --section-secondary: var(--inverse-secondary);
  --section-line: var(--inverse-line);
  background: #050706;
}

.center-heading.inverse .eyebrow,
.center-heading.inverse > p:last-child {
  color: var(--section-secondary);
}

.service-paths {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--section-line);
  border-bottom: 1px solid var(--section-line);
}

.service-paths article {
  display: flex;
  min-height: 390px;
  padding: 32px;
  border-right: 1px solid var(--section-line);
  flex-direction: column;
}

.service-paths article:first-child {
  padding-left: 0;
}

.service-paths article:last-child {
  padding-right: 0;
  border-right: 0;
}

.path-number {
  color: var(--section-secondary);
  font-size: 0.68rem;
  font-weight: 700;
}

.service-paths .material-symbols-rounded {
  display: block;
  width: 34px;
  height: 1px;
  margin: 46px 0 25px;
  background: var(--section-line);
}

.service-paths h3 {
  margin-bottom: 12px;
  font-size: 1.55rem;
}

.service-paths p {
  color: var(--section-secondary);
  line-height: 1.7;
}

.path-note {
  margin-top: auto;
  padding-top: 24px;
  color: var(--section-ink);
  font-size: 0.74rem;
}

.privacy-proof {
  display: flex;
  gap: 32px;
  align-items: center;
  justify-content: space-between;
  margin-top: 54px;
}

.privacy-proof > div {
  display: flex;
  gap: 15px;
  align-items: center;
}

.privacy-proof > div > .material-symbols-rounded {
  width: 30px;
  height: 30px;
  color: var(--accent);
}

.privacy-proof h3 {
  margin: 0;
  font-size: clamp(1.2rem, 2vw, 1.55rem);
}

.inverse-link {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  color: var(--section-secondary);
  font-size: 0.84rem;
  font-weight: 650;
}

.inverse-link:hover,
.inverse-link:focus-visible {
  color: var(--section-ink);
}

.platforms-section {
  background: var(--surface);
}

.platform-stories {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.platform-stories article {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 30px;
  min-height: 360px;
  padding: 52px 52px 52px 0;
  border-right: 1px solid var(--line);
}

.platform-stories article:last-child {
  padding-right: 0;
  padding-left: 52px;
  border-right: 0;
}

.platform-symbol {
  display: grid;
  width: 110px;
  height: 150px;
  align-self: start;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--surface-soft);
  color: var(--ink-secondary);
  place-items: center;
}

.platform-symbol .material-symbols-rounded {
  font-size: 42px;
}

.mac-symbol {
  width: 116px;
  height: 96px;
  border-radius: 18px;
}

.option-key {
  font-size: 2.4rem;
  font-weight: 500;
}

.platform-stories h3 {
  margin: 26px 0 12px;
  font-size: clamp(1.5rem, 2.5vw, 2.1rem);
  letter-spacing: -0.035em;
  line-height: 1.2;
}

html[data-lang="zh"] .platform-stories h3 {
  letter-spacing: -0.02em;
}

.platform-stories p {
  margin: 0;
  color: var(--ink-secondary);
  line-height: 1.75;
}

.platform-footnote {
  margin: 20px 0 0;
  color: var(--ink-tertiary);
  font-size: 0.76rem;
  text-align: center;
}

.start-section {
  background: var(--canvas);
}

.split-heading {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.65fr);
  gap: 80px;
  align-items: end;
  margin-bottom: 58px;
}

.split-heading h2 {
  max-width: 760px;
  margin: 0;
}

.split-heading > p {
  margin: 0;
}

.setup-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-strong);
  counter-reset: setup;
  list-style: none;
}

.setup-steps li {
  min-height: 260px;
  padding: 30px 30px 30px 0;
  border-right: 1px solid var(--line);
  counter-increment: setup;
}

.setup-steps li:not(:first-child) {
  padding-left: 30px;
}

.setup-steps li:last-child {
  border-right: 0;
}

.setup-steps li::before {
  display: block;
  margin-bottom: 60px;
  color: var(--ink-tertiary);
  content: "0" counter(setup);
  font-size: 0.7rem;
  font-weight: 700;
}

.setup-steps h3 {
  margin-bottom: 10px;
  font-size: 1.3rem;
}

.setup-steps p {
  margin: 0;
  color: var(--ink-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}

.stable-strip {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 48px;
  align-items: center;
  margin-top: 28px;
  padding: 24px 28px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
}

.stable-strip > span {
  font-size: 0.82rem;
  font-weight: 700;
}

.stable-strip ul {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin: 0;
  padding: 0;
  color: var(--ink-secondary);
  font-size: 0.76rem;
  list-style: none;
}

.stable-strip li {
  padding-left: 13px;
  border-left: 1px solid var(--line);
}

.faq-section {
  background: var(--surface);
}

.faq-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.7fr) minmax(0, 1.3fr);
  gap: clamp(70px, 10vw, 140px);
  align-items: start;
}

.faq-layout h2 {
  margin: 0;
}

.faq-list {
  border-top: 1px solid var(--line);
}

.faq-item {
  border-bottom: 1px solid var(--line);
}

.faq-item summary {
  display: flex;
  gap: 20px;
  align-items: center;
  justify-content: space-between;
  padding: 23px 0;
  cursor: pointer;
  font-size: 1.05rem;
  font-weight: 650;
  list-style: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  color: var(--ink-tertiary);
  content: "+";
  font-size: 1.3rem;
  font-weight: 400;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item p {
  padding: 0 0 23px;
  color: var(--ink-secondary);
  line-height: 1.7;
}

.download-section {
  background: var(--surface);
  padding-top: 0;
}

.download-panel {
  --panel-ink: var(--ink);
  --panel-secondary: var(--ink-secondary);
  --panel-line: var(--line);
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 70px;
  align-items: end;
  padding: clamp(44px, 7vw, 80px);
  border-radius: var(--radius-xl);
  background: #e2e7eb;
  color: var(--panel-ink);
}

html[data-theme="dark"] .download-panel {
  --panel-ink: var(--inverse);
  --panel-secondary: var(--inverse-secondary);
  --panel-line: var(--inverse-line);
  background: #151817;
}

.download-panel .eyebrow {
  color: var(--panel-secondary);
}

.download-panel h2 {
  max-width: 720px;
  margin-bottom: 15px;
  font-size: clamp(2.8rem, 4.8vw, 4.2rem);
  letter-spacing: -0.055em;
  line-height: 1.05;
}

html[data-lang="zh"] .download-panel h2 {
  font-size: clamp(2.3rem, 3.8vw, 3.3rem);
  letter-spacing: -0.03em;
  line-height: 1.12;
}

.download-panel p:last-child {
  max-width: 650px;
  margin-bottom: 0;
  color: var(--panel-secondary);
}

.download-actions {
  max-width: 370px;
  justify-content: flex-end;
}

.outline-action {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  min-height: 48px;
  padding: 0 16px;
  border: 1px solid var(--panel-line);
  border-radius: 10px;
  color: var(--panel-secondary);
  font-size: 0.82rem;
  font-weight: 650;
}

.outline-action:hover,
.outline-action:focus-visible {
  border-color: var(--line-strong);
  color: var(--panel-ink);
}

.outline-action .material-symbols-rounded {
  font-size: 19px;
}

.site-footer {
  padding: 38px 0 48px;
  background: var(--surface);
}

.footer-inner {
  display: flex;
  gap: 24px;
  align-items: center;
  justify-content: space-between;
  width: var(--content);
  margin: auto;
  color: var(--ink-secondary);
  font-size: 0.78rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 17px;
}

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

@media (max-width: 1040px) {
  :root {
    --content: min(100% - 48px, 1200px);
  }

  .scene-layout,
  .skills-layout {
    grid-template-columns: minmax(0, 0.75fr) minmax(470px, 1.25fr);
    gap: 54px;
  }

  .platform-stories article {
    grid-template-columns: 1fr;
  }

  .platform-stories article:last-child {
    padding-left: 40px;
  }

  .stable-strip {
    grid-template-columns: 1fr;
    gap: 16px;
  }
}

@media (max-width: 860px) {
  :root {
    --content: min(100% - 36px, 1200px);
  }

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

  .nav-links {
    display: none;
  }

  .icon-button.mobile-menu-button {
    display: inline-grid;
  }

  .mobile-nav:not([hidden]) {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
  }

  .stage-content,
  .scene-layout,
  .skills-layout,
  .typing-story,
  .styles-strip,
  .split-heading,
  .faq-layout,
  .download-panel {
    grid-template-columns: 1fr;
  }

  .stage-content {
    min-height: auto;
  }

  .conversation {
    min-height: 480px;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .keyboard-demo {
    min-height: 430px;
  }

  .scene-copy {
    max-width: 690px;
  }

  .typing-story.reverse .typing-visual {
    order: 0;
    border-bottom: 1px solid var(--line);
    border-left: 0;
  }

  .typing-visual {
    min-height: 420px;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .story-copy {
    min-height: 330px;
  }

  .styles-strip {
    gap: 34px;
    align-items: start;
  }

  .service-paths {
    grid-template-columns: 1fr;
  }

  .service-paths article,
  .service-paths article:first-child,
  .service-paths article:last-child {
    min-height: 300px;
    padding: 30px 0;
    border-right: 0;
    border-bottom: 1px solid var(--section-line);
  }

  .service-paths article:last-child {
    border-bottom: 0;
  }

  .service-paths .material-symbols-rounded {
    margin: 28px 0 20px;
  }

  .privacy-proof {
    align-items: flex-start;
    flex-direction: column;
  }

  .platform-stories {
    grid-template-columns: 1fr;
  }

  .platform-stories article,
  .platform-stories article:last-child {
    grid-template-columns: 120px 1fr;
    min-height: auto;
    padding: 40px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .platform-stories article:last-child {
    border-bottom: 0;
  }

  .split-heading {
    gap: 24px;
  }

  .download-panel {
    align-items: start;
    gap: 34px;
  }

  .download-actions {
    justify-content: flex-start;
  }
}

@media (max-width: 640px) {
  :root {
    --content: min(100% - 28px, 1200px);
    --radius-xl: 24px;
    --radius-lg: 20px;
  }

  .site-nav {
    top: 8px;
  }

  .nav-shell {
    min-height: 50px;
    padding: 5px 5px 5px 10px;
    border-radius: 14px;
  }

  .brand span {
    display: none;
  }

  .mobile-nav {
    border-radius: 14px;
  }

  .mobile-nav a {
    padding: 10px 4px;
    font-size: 0.76rem;
  }

  .hero {
    min-height: 780px;
    padding: 108px 0 86px;
  }

  .launch-pill {
    margin-bottom: 54px;
    font-size: 0.7rem;
  }

  .hero h1,
  html[data-lang="zh"] .hero h1 {
    font-size: clamp(2rem, 9vw, 2.2rem);
  }

  .hero h1 > span {
    white-space: nowrap;
  }

  .hero-copy {
    font-size: 1rem;
  }

  .hero-actions {
    flex-direction: column;
  }

  .hero-note {
    max-width: 310px;
    line-height: 1.6;
  }

  .scroll-cue {
    white-space: nowrap;
  }

  .section {
    padding: 82px 0;
  }

  .center-heading h2,
  .scene-copy h2,
  .split-heading h2,
  .faq-layout h2,
  html[data-lang="zh"] .center-heading h2,
  html[data-lang="zh"] .scene-copy h2,
  html[data-lang="zh"] .split-heading h2,
  html[data-lang="zh"] .faq-layout h2 {
    font-size: 2.2rem;
  }

  .stage-bar {
    grid-template-columns: 1fr auto;
  }

  .stage-dots {
    display: none;
  }

  .stage-status {
    display: none;
  }

  .conversation {
    min-height: 420px;
    padding: 28px 20px;
  }

  .message-bubble {
    font-size: 1rem;
  }

  .insert-preview {
    padding: 18px;
  }

  .keyboard-demo {
    min-height: 360px;
  }

  .assistant-tabs {
    grid-template-columns: 42px repeat(3, auto) 1fr;
    gap: 3px;
    padding: 13px 10px;
  }

  .assistant-tab {
    padding: 6px;
  }

  .keyboard-keys {
    gap: 4px;
    padding: 45px 10px 16px;
  }

  .keyboard-keys span {
    height: 36px;
    font-size: 0.65rem;
  }

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

  .gesture-grid article,
  .gesture-grid article:not(:first-child) {
    min-height: 120px;
    padding: 23px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .gesture-grid article:last-child {
    border-bottom: 0;
  }

  .voice-stage,
  .skills-stage {
    padding: 24px 20px;
  }

  .transcript-card {
    min-height: 210px;
  }

  .waveform {
    gap: 5px;
  }

  .typing-visual {
    min-height: 350px;
    padding: 28px 20px;
  }

  .story-copy {
    min-height: 290px;
    padding: 28px 22px;
  }

  .story-copy h3 {
    margin-top: 54px;
  }

  .mini-keyboard {
    gap: 4px;
  }

  .mini-keyboard span {
    height: 34px;
    font-size: 0.62rem;
  }

  .english-line {
    font-size: 1.55rem;
  }

  .skills-stage {
    min-height: 440px;
  }

  .skill-actions {
    grid-template-columns: repeat(2, 1fr);
  }

  .styles-strip {
    margin-top: 80px;
  }

  .style-options {
    grid-template-columns: 1fr;
  }

  .privacy-proof h3 {
    font-size: 1.08rem;
  }

  .platform-stories article,
  .platform-stories article:last-child {
    grid-template-columns: 1fr;
    gap: 22px;
  }

  .platform-symbol {
    width: 92px;
    height: 122px;
    border-radius: 23px;
  }

  .mac-symbol {
    height: 76px;
    border-radius: 16px;
  }

  .setup-steps {
    grid-template-columns: 1fr;
  }

  .setup-steps li,
  .setup-steps li:not(:first-child) {
    min-height: auto;
    padding: 25px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .setup-steps li::before {
    margin-bottom: 34px;
  }

  .stable-strip {
    padding: 22px;
  }

  .stable-strip ul {
    grid-template-columns: repeat(2, 1fr);
  }

  .download-panel {
    padding: 34px 22px;
  }

  .download-panel h2,
  html[data-lang="zh"] .download-panel h2 {
    font-size: 2.25rem;
  }

  .download-actions {
    align-items: flex-start;
    flex-direction: column;
  }

  .footer-inner {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}