:root {
  color-scheme: light;
  --ink: #181a18;
  --muted: #6d706b;
  --paper: #f6f3eb;
  --surface: #fffdf8;
  --line: rgba(24, 26, 24, 0.14);
  --accent: #ff5c35;
  --accent-soft: #ffd5c9;
  --accent-ink: #32180f;
  --page: min(1120px, calc(100% - 40px));
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Helvetica Neue", sans-serif;
  font-synthesis: none;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 2%, color-mix(in srgb, var(--accent) 12%, transparent), transparent 28rem),
    radial-gradient(circle at 95% 18%, color-mix(in srgb, var(--accent-soft) 45%, transparent), transparent 26rem),
    var(--paper);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

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

.language-en,
.language-zh { display: none; }

html[data-language="en"] .language-en,
html[data-language="zh"] .language-zh { display: revert; }

html[data-language="en"] .language-zh,
html[data-language="zh"] .language-en { display: none !important; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 84%, transparent);
  backdrop-filter: blur(18px) saturate(1.2);
}

.nav,
.page-shell,
.footer-inner {
  width: var(--page);
  margin: 0 auto;
}

.nav {
  min-height: 74px;
  display: flex;
  gap: 26px;
  align-items: center;
}

.brand {
  margin-right: auto;
  display: inline-flex;
  gap: 11px;
  align-items: center;
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  text-decoration: none;
}

.brand img {
  width: 36px;
  height: 36px;
  object-fit: cover;
  border-radius: 10px;
  box-shadow: 0 7px 18px color-mix(in srgb, var(--accent) 18%, transparent);
}

.nav-links {
  display: flex;
  gap: 24px;
  align-items: center;
}

.nav-links a {
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 650;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] { color: var(--ink); }

.language-switch {
  padding: 3px;
  display: inline-flex;
  gap: 2px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255,255,255,0.58);
}

.language-switch button {
  min-width: 38px;
  padding: 5px 9px;
  color: var(--muted);
  background: transparent;
  border: 0;
  border-radius: 999px;
  font: inherit;
  font-size: 0.74rem;
  font-weight: 760;
  cursor: pointer;
}

.language-switch button[aria-pressed="true"] {
  color: #fff;
  background: var(--ink);
}

.language-switch button:focus-visible,
a:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

.product-hero {
  min-height: 660px;
  padding: 82px 0 96px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(380px, 0.9fr);
  gap: 80px;
  align-items: center;
}

.eyebrow {
  margin: 0 0 20px;
  color: var(--muted);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.product-copy h1,
.page-intro h1 {
  margin: 0;
  font-size: clamp(3.5rem, 7vw, 6.4rem);
  line-height: 0.92;
  letter-spacing: -0.075em;
}

.product-copy h2 {
  max-width: 700px;
  margin: 24px 0 0;
  color: var(--accent-ink);
  font-family: ui-serif, Georgia, "Songti SC", serif;
  font-size: clamp(1.65rem, 3vw, 2.7rem);
  font-weight: 520;
  line-height: 1.18;
  letter-spacing: -0.035em;
}

.product-copy > div > p:not(.eyebrow) {
  max-width: 650px;
  margin: 26px 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.actions {
  margin-top: 34px;
  display: flex;
  flex-wrap: wrap;
  gap: 11px;
}

.button {
  min-height: 48px;
  padding: 0 20px;
  display: inline-flex;
  gap: 10px;
  align-items: center;
  justify-content: center;
  color: #fff;
  background: var(--ink);
  border: 1px solid var(--ink);
  border-radius: 999px;
  font-size: 0.88rem;
  font-weight: 760;
  text-decoration: none;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.button.secondary {
  color: var(--ink);
  background: transparent;
  border-color: var(--line);
}

.button:hover {
  transform: translateY(-2px);
  box-shadow: 0 9px 0 color-mix(in srgb, var(--accent) 24%, transparent);
}

.app-stage {
  position: relative;
  min-height: 480px;
  display: grid;
  place-items: center;
  overflow: visible;
  background: linear-gradient(145deg, var(--accent-soft), color-mix(in srgb, var(--accent) 35%, #fff));
  border: 1px solid var(--line);
  border-radius: 42% 58% 52% 48% / 46% 45% 55% 54%;
}

.app-stage::before,
.app-stage::after {
  content: "";
  position: absolute;
  border: 1px solid color-mix(in srgb, var(--accent-ink) 22%, transparent);
  border-radius: 50%;
}

.app-stage::before { inset: 11%; transform: rotate(13deg); }
.app-stage::after { inset: 25% 4%; transform: rotate(-28deg); }

.app-icon-large {
  position: relative;
  z-index: 2;
  width: min(48%, 220px);
  aspect-ratio: 1;
  object-fit: contain;
  border-radius: 25%;
  box-shadow: 22px 26px 0 color-mix(in srgb, var(--accent-ink) 18%, transparent), 0 32px 80px rgba(0,0,0,0.2);
  transform: rotate(-5deg);
}

.platform-label {
  position: absolute;
  left: 50%;
  bottom: 8%;
  z-index: 3;
  padding: 10px 14px;
  color: #fff;
  background: var(--ink);
  border-radius: 999px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.66rem;
  font-weight: 800;
  letter-spacing: 0.07em;
  white-space: nowrap;
  box-shadow: 6px 7px 0 var(--accent);
  transform: translateX(-50%);
}

.section { padding: 120px 0; }

.section-heading {
  margin-bottom: 48px;
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(260px, 0.65fr);
  gap: 60px;
  align-items: end;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(2.6rem, 5vw, 4.7rem);
  line-height: 0.98;
  letter-spacing: -0.065em;
}

.section-heading p {
  margin: 0;
  color: var(--muted);
  font-size: 1rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.feature-card {
  min-height: 280px;
  padding: 28px;
  display: flex;
  flex-direction: column;
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  border: 1px solid var(--line);
  border-radius: 24px;
}

.feature-symbol {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  color: var(--accent-ink);
  background: var(--accent-soft);
  border-radius: 15px;
  font-size: 1.25rem;
  font-weight: 800;
}

.feature-card h3 {
  margin: auto 0 10px;
  font-size: 1.4rem;
  line-height: 1.1;
  letter-spacing: -0.035em;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.91rem;
}

.privacy-callout,
.contact-panel {
  margin-bottom: 110px;
  padding: clamp(30px, 6vw, 68px);
  display: flex;
  gap: 34px;
  align-items: center;
  justify-content: space-between;
  color: #fff;
  background: var(--ink);
  border-radius: 28px;
}

.privacy-callout h2,
.contact-panel h2 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.7rem);
  line-height: 1;
  letter-spacing: -0.055em;
}

.privacy-callout p,
.contact-panel p {
  max-width: 690px;
  margin: 15px 0 0;
  color: rgba(255,255,255,0.62);
}

.privacy-callout .button,
.contact-panel .button {
  flex: 0 0 auto;
  color: var(--ink);
  background: #fff;
  border-color: #fff;
}

.page-main { padding: 92px 0 120px; }

.page-intro {
  max-width: 850px;
  margin-bottom: 64px;
}

.page-intro h1 { font-size: clamp(3.3rem, 6vw, 5.4rem); }

.page-intro > p:not(.eyebrow) {
  max-width: 700px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.updated {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.75rem !important;
  letter-spacing: 0.04em;
}

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

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

.faq-item summary {
  padding: 25px 44px 25px 0;
  position: relative;
  list-style: none;
  font-size: 1.17rem;
  font-weight: 760;
  cursor: pointer;
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 2px;
  top: 21px;
  font-size: 1.5rem;
  font-weight: 400;
}

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

.faq-answer {
  max-width: 820px;
  padding: 0 0 28px;
  color: var(--muted);
}

.faq-answer p { margin: 0; }

.support-contact { margin-top: 70px; }

.content-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.legal-section {
  padding: 28px;
  background: color-mix(in srgb, var(--surface) 90%, transparent);
  border: 1px solid var(--line);
  border-radius: 20px;
}

.legal-section.full { grid-column: 1 / -1; }

.legal-section h2 {
  margin: 0 0 12px;
  font-size: 1.2rem;
  letter-spacing: -0.025em;
}

.legal-section p {
  margin: 0;
  color: var(--muted);
  font-size: 0.91rem;
}

.legal-section a { color: var(--ink); font-weight: 700; }

.footer {
  border-top: 1px solid var(--line);
  background: rgba(255,255,255,0.28);
}

.footer-inner {
  min-height: 100px;
  display: flex;
  gap: 28px;
  align-items: center;
  justify-content: space-between;
  color: var(--muted);
  font-size: 0.78rem;
}

.footer-links { display: flex; gap: 20px; }
.footer-links a { font-weight: 680; text-decoration: none; }

@media (max-width: 820px) {
  .nav-links a:first-child { display: none; }
  .product-hero { grid-template-columns: 1fr; gap: 48px; }
  .app-stage { min-height: 430px; }
  .section-heading { grid-template-columns: 1fr; gap: 22px; }
  .feature-grid { grid-template-columns: 1fr; }
  .feature-card { min-height: 220px; }
}

@media (max-width: 600px) {
  :root { --page: calc(100% - 28px); }
  .nav { gap: 12px; }
  .nav-links { gap: 13px; }
  .nav-links a { font-size: 0.78rem; }
  .brand span { display: none; }
  .product-hero { min-height: auto; padding: 62px 0 76px; }
  .app-stage { min-height: 340px; border-radius: 34px; }
  .section { padding: 90px 0; }
  .privacy-callout,
  .contact-panel { align-items: flex-start; flex-direction: column; }
  .content-grid { grid-template-columns: 1fr; }
  .legal-section.full { grid-column: auto; }
  .footer-inner { padding: 28px 0; align-items: flex-start; flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.01ms !important; }
}