:root {
  color-scheme: light;
  --ink: #17201e;
  --ink-soft: #53605c;
  --ink-faint: #75807c;
  --paper: #f4f5f0;
  --paper-deep: #eaeee7;
  --surface: rgba(255, 255, 252, 0.82);
  --line: #d6ddd5;
  --accent: #247f65;
  --accent-bright: #35b88e;
  --accent-pale: #dcece5;
  --dark: #0e1312;
  --serif: ui-serif, "Songti SC", "STSong", "SimSun", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-family: var(--sans);
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* {
  box-sizing: border-box;
}

html {
  background: var(--paper);
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 84% 6%, rgba(53, 184, 142, 0.09), transparent 29rem),
    linear-gradient(180deg, #f7f8f4 0%, var(--paper) 54%, #eef1eb 100%);
  font-size: 16px;
  line-height: 1.75;
}

a {
  color: var(--accent);
  text-underline-offset: 0.22em;
  text-decoration-thickness: 1px;
}

a:hover {
  color: #17684f;
}

a:focus-visible {
  outline: 3px solid rgba(53, 184, 142, 0.42);
  outline-offset: 4px;
  border-radius: 3px;
}

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

.site-shell {
  width: min(100% - 40px, 820px);
  margin-inline: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
  border-bottom: 1px solid rgba(23, 32, 30, 0.1);
}

.brand-link {
  display: inline-flex;
  align-items: baseline;
  gap: 9px;
  color: var(--ink);
  text-decoration: none;
}

.brand-cn {
  font-family: var(--serif);
  font-size: 19px;
  letter-spacing: 0.16em;
}

.brand-en {
  color: var(--ink-faint);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.site-nav {
  display: flex;
  gap: 20px;
  font-size: 14px;
}

.site-nav a {
  color: var(--ink-soft);
  text-decoration: none;
}

.site-nav a[aria-current="page"] {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--accent-bright);
}

main {
  padding-block: 68px 92px;
}

.hero {
  padding-block: 40px 64px;
}

.hero-lockup {
  display: grid;
  grid-template-columns: 116px minmax(0, 1fr);
  align-items: center;
  gap: 36px;
}

.app-icon {
  width: 116px;
  aspect-ratio: 1;
  border-radius: 25px;
  box-shadow: 0 18px 42px rgba(14, 19, 18, 0.15);
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  font-family: var(--serif);
  font-weight: 500;
  color: var(--ink);
}

h1 {
  max-width: 16ch;
  margin: 0;
  font-size: clamp(38px, 7vw, 66px);
  line-height: 1.12;
  letter-spacing: 0.02em;
}

.hero-title-en {
  display: block;
  margin-top: 3px;
  color: var(--ink-soft);
  font-family: var(--sans);
  font-size: 0.42em;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.hero-copy {
  max-width: 590px;
  margin: 36px 0 0;
}

.hero-lead {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: clamp(22px, 4vw, 30px);
  line-height: 1.45;
}

.hero-detail {
  margin: 0;
  color: var(--ink-soft);
  font-size: 17px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin: 20px 0 0;
  border-block: 1px solid var(--line);
}

.feature {
  min-height: 188px;
  padding: 28px 24px 30px;
}

.feature + .feature {
  border-left: 1px solid var(--line);
}

.feature-index {
  color: var(--accent);
  font-size: 12px;
  letter-spacing: 0.14em;
}

.feature h2 {
  margin: 12px 0 8px;
  font-size: 22px;
}

.feature p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 15px;
  line-height: 1.7;
}

.entry-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 46px;
}

.button-link {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border: 1px solid var(--ink);
  border-radius: 999px;
  color: var(--ink);
  font-size: 15px;
  text-decoration: none;
}

.button-link.primary {
  border-color: var(--dark);
  color: #f1f4ef;
  background: var(--dark);
}

.button-link:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.button-link.primary:hover {
  color: #fff;
  background: #1b2825;
}

.document {
  width: min(100% - 40px, 760px);
  margin-inline: auto;
}

.document-header {
  padding-bottom: 38px;
  border-bottom: 1px solid var(--line);
}

.document-header h1 {
  max-width: none;
  font-size: clamp(34px, 6vw, 50px);
}

.effective-date,
.document-intro {
  margin: 18px 0 0;
  color: var(--ink-soft);
}

.document section {
  padding-block: 34px;
  border-bottom: 1px solid var(--line);
}

.document section:last-of-type {
  border-bottom: 0;
}

.document h2 {
  margin: 0 0 14px;
  font-size: 24px;
  line-height: 1.4;
}

.document h3 {
  margin: 24px 0 8px;
  font-size: 18px;
}

.document p {
  margin: 0 0 13px;
}

.document ul {
  margin: 12px 0 16px;
  padding-left: 1.4em;
}

.document li + li {
  margin-top: 5px;
}

.notice {
  margin-block: 18px;
  padding: 17px 19px;
  border-left: 3px solid var(--accent-bright);
  background: var(--accent-pale);
}

.notice p:last-child {
  margin-bottom: 0;
}

.back-link {
  display: inline-block;
  margin-top: 36px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding-block: 26px 34px;
  border-top: 1px solid rgba(23, 32, 30, 0.1);
  color: var(--ink-faint);
  font-size: 13px;
}

.site-footer p {
  margin: 0;
}

@media (max-width: 680px) {
  .site-shell,
  .document {
    width: min(100% - 32px, 820px);
  }

  .site-header {
    min-height: 66px;
  }

  .site-nav {
    gap: 14px;
    font-size: 13px;
  }

  main {
    padding-block: 46px 68px;
  }

  .hero {
    padding-block: 26px 48px;
  }

  .hero-lockup {
    grid-template-columns: 82px minmax(0, 1fr);
    gap: 22px;
  }

  .app-icon {
    width: 82px;
    border-radius: 18px;
  }

  .hero-copy {
    margin-top: 30px;
  }

  .hero-detail {
    font-size: 16px;
  }

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

  .feature {
    min-height: 0;
    padding: 24px 4px 26px;
  }

  .feature + .feature {
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .entry-links {
    display: grid;
    grid-template-columns: 1fr 1fr;
    margin-top: 38px;
  }

  .document-header {
    padding-bottom: 30px;
  }

  .document section {
    padding-block: 29px;
  }

  .document h2 {
    font-size: 22px;
  }
}

@media (max-width: 410px) {
  .brand-en {
    display: none;
  }

  .site-nav {
    gap: 12px;
  }

  .entry-links {
    grid-template-columns: 1fr;
  }
}

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