:root {
  color-scheme: light;
  --ink: #17212b;
  --muted: #66717d;
  --paper: #f6f4ef;
  --surface: rgba(255, 255, 255, 0.76);
  --line: rgba(23, 33, 43, 0.13);
  --accent: #e9553e;
  --accent-dark: #b9342a;
  --night: #15202a;
  --focus: #7158d9;
  --radius: 22px;
  --shadow: 0 18px 50px rgba(24, 32, 40, 0.09);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 2%, rgba(233, 85, 62, 0.11), transparent 28rem),
    radial-gradient(circle at 92% 12%, rgba(113, 88, 217, 0.08), transparent 30rem),
    var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid rgba(113, 88, 217, 0.48);
  outline-offset: 3px;
}

.shell {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  padding: 26px 0;
}

.site-header .shell,
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  font-weight: 760;
  letter-spacing: -0.025em;
}

.brand-mark {
  position: relative;
  width: 28px;
  height: 28px;
  border-radius: 9px;
  background: var(--night);
  box-shadow: inset -7px -7px 0 var(--accent);
  transform: rotate(-8deg);
}

.brand-mark::after {
  content: "";
  position: absolute;
  width: 7px;
  height: 7px;
  right: 5px;
  top: 5px;
  border-radius: 50%;
  background: var(--paper);
}

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

.nav a,
.language-switch button {
  border: 0;
  border-radius: 999px;
  padding: 8px 12px;
  color: var(--muted);
  background: transparent;
  font: inherit;
  font-size: 0.9rem;
  text-decoration: none;
  cursor: pointer;
}

.nav a:hover,
.language-switch button:hover,
.language-switch button[aria-pressed="true"] {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.78);
}

.language-switch {
  display: inline-flex;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.48);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(280px, 0.75fr);
  gap: 54px;
  align-items: end;
  padding: 105px 0 92px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--accent-dark);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

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

h1 {
  max-width: 820px;
  margin-bottom: 26px;
  font-size: clamp(3.15rem, 8vw, 6.8rem);
  line-height: 0.94;
  letter-spacing: -0.075em;
}

.hero-copy {
  max-width: 640px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.28rem);
}

.hero-note {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.hero-note strong {
  display: block;
  margin-bottom: 8px;
  font-size: 0.88rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.hero-note p {
  margin-bottom: 0;
  color: var(--muted);
}

.section {
  padding: 70px 0 110px;
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 30px;
  margin-bottom: 34px;
}

.section-heading h2 {
  margin-bottom: 0;
  font-size: clamp(2rem, 4vw, 3.4rem);
  line-height: 1;
  letter-spacing: -0.05em;
}

.section-heading p {
  max-width: 460px;
  margin-bottom: 0;
  color: var(--muted);
}

.product-card {
  display: grid;
  grid-template-columns: 86px minmax(0, 1fr) auto;
  gap: 26px;
  align-items: center;
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.app-icon {
  display: grid;
  width: 86px;
  height: 86px;
  place-items: center;
  border-radius: 22px;
  color: white;
  background: linear-gradient(145deg, #f26b54, #bd3f5d 58%, #604fc6);
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.08em;
  box-shadow: inset 0 1px rgba(255, 255, 255, 0.3);
}

.product-card h3 {
  margin-bottom: 7px;
  font-size: 1.55rem;
  letter-spacing: -0.035em;
}

.product-card p {
  margin-bottom: 0;
  color: var(--muted);
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.tag {
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  font-size: 0.78rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 11px 18px;
  border-radius: 999px;
  color: white;
  background: var(--night);
  font-weight: 720;
  text-decoration: none;
  white-space: nowrap;
  transition: transform 160ms ease, background 160ms ease;
}

.button:hover {
  background: #263745;
  transform: translateY(-1px);
}

.document-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 230px;
  gap: 58px;
  align-items: start;
  padding: 80px 0 110px;
}

.document {
  padding: clamp(30px, 5vw, 68px);
  border: 1px solid var(--line);
  border-radius: 30px;
  background: rgba(255, 255, 255, 0.79);
  box-shadow: var(--shadow);
}

.document h1 {
  margin-bottom: 18px;
  font-size: clamp(2.6rem, 7vw, 5.2rem);
}

.document .lede {
  max-width: 720px;
  margin-bottom: 48px;
  color: var(--muted);
  font-size: 1.1rem;
}

.document section + section {
  margin-top: 44px;
  padding-top: 42px;
  border-top: 1px solid var(--line);
}

.document h2 {
  margin-bottom: 15px;
  font-size: 1.45rem;
  line-height: 1.25;
  letter-spacing: -0.028em;
}

.document h3 {
  margin: 28px 0 8px;
  font-size: 1.05rem;
}

.document p:last-child,
.document ul:last-child {
  margin-bottom: 0;
}

.document ul,
.document ol {
  padding-left: 1.35rem;
}

.document li + li {
  margin-top: 8px;
}

.meta-line {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-bottom: 22px;
  color: var(--muted);
  font-size: 0.86rem;
}

.side-nav {
  position: sticky;
  top: 26px;
  padding: 21px;
  border-left: 2px solid var(--line);
}

.side-nav strong {
  display: block;
  margin-bottom: 12px;
  font-size: 0.77rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.side-nav a {
  display: block;
  padding: 6px 0;
  color: var(--muted);
  font-size: 0.88rem;
  text-decoration: none;
}

.side-nav a:hover {
  color: var(--ink);
}

.notice {
  margin: 28px 0;
  padding: 20px 22px;
  border-left: 4px solid var(--accent);
  border-radius: 0 14px 14px 0;
  background: rgba(233, 85, 62, 0.08);
}

.contact-card {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--paper);
}

.contact-card a {
  color: var(--accent-dark);
  font-weight: 720;
}

.site-footer {
  padding: 30px 0 42px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.88rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

.footer-links a {
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--ink);
}

[data-lang] {
  display: none;
}

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

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

[data-lang-inline] {
  display: none;
}

@media (max-width: 820px) {
  .hero,
  .document-wrap {
    grid-template-columns: 1fr;
  }

  .hero {
    gap: 34px;
    padding: 70px 0 72px;
  }

  .side-nav {
    display: none;
  }

  .product-card {
    grid-template-columns: 68px minmax(0, 1fr);
  }

  .app-icon {
    width: 68px;
    height: 68px;
    border-radius: 18px;
  }

  .product-card .button {
    grid-column: 1 / -1;
  }
}

@media (max-width: 600px) {
  .shell {
    width: min(100% - 28px, 1120px);
  }

  .site-header .shell,
  .footer-inner,
  .section-heading {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-header .shell {
    gap: 16px;
  }

  .nav {
    width: 100%;
    justify-content: space-between;
  }

  h1 {
    font-size: clamp(3rem, 18vw, 4.8rem);
  }

  .product-card {
    padding: 24px;
  }

  .document-wrap {
    padding: 42px 0 80px;
  }

  .document {
    padding: 26px 22px;
    border-radius: 22px;
  }
}

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

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}