:root {
  color-scheme: light dark;
  --page: #f7f8fc;
  --surface: rgba(255, 255, 255, 0.86);
  --surface-solid: #ffffff;
  --text: #171927;
  --muted: #62677a;
  --line: rgba(49, 55, 84, 0.14);
  --accent: #4358e8;
  --accent-strong: #3043c7;
  --accent-soft: rgba(67, 88, 232, 0.1);
  --blue: #2f65ee;
  --violet: #6845e9;
  --teal: #0b7385;
  --focus-ring: #243cc4;
  --shadow: 0 18px 54px rgba(41, 47, 86, 0.1);
  --radius: 20px;
  --content: 1040px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
  text-size-adjust: 100%;
}

body {
  min-width: 320px;
  margin: 0;
  background:
    radial-gradient(circle at 8% 2%, rgba(47, 101, 238, 0.1), transparent 30rem),
    radial-gradient(circle at 94% 16%, rgba(32, 167, 186, 0.08), transparent 26rem),
    var(--page);
  color: var(--text);
  font-family: system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.65;
}

a {
  color: var(--accent);
  overflow-wrap: anywhere;
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--accent-strong);
}

a:focus-visible {
  border-radius: 6px;
  outline: 3px solid var(--focus-ring);
  outline-offset: 3px;
}

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

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  transform: translateY(-180%);
  padding: 9px 13px;
  border-radius: 9px;
  background: var(--surface-solid);
  color: var(--text);
  box-shadow: var(--shadow);
}

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

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  border-bottom: 1px solid var(--line);
  background: rgba(247, 248, 252, 0.9);
  backdrop-filter: blur(18px);
}

.header-inner,
.page-shell,
.footer-inner {
  width: min(calc(100% - 40px), var(--content));
  margin-inline: auto;
}

.header-inner {
  display: flex;
  min-height: 68px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-size: 18px;
  font-weight: 750;
  text-decoration: none;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 9px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav a {
  padding: 7px 10px;
  border-radius: 999px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  background: var(--accent-soft);
  color: var(--accent);
}

.page-shell {
  padding-block: 70px 88px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 0.55fr);
  min-height: 470px;
  align-items: center;
  gap: clamp(36px, 8vw, 84px);
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 760;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin-top: 0;
  line-height: 1.16;
  letter-spacing: -0.03em;
}

h1 {
  max-width: 780px;
  margin-bottom: 20px;
  font-size: clamp(42px, 6.4vw, 68px);
  font-weight: 820;
}

h2 {
  margin-bottom: 16px;
  font-size: clamp(29px, 4vw, 40px);
  font-weight: 780;
}

h3 {
  margin-bottom: 8px;
  font-size: 20px;
  font-weight: 730;
}

.gradient-text {
  background: linear-gradient(118deg, var(--blue), var(--violet) 52%, var(--teal));
  background-clip: text;
  color: transparent;
}

html[lang="zh-Hans"] .gradient-text {
  white-space: nowrap;
}

.hero-copy {
  max-width: 660px;
  margin: 0;
  color: var(--muted);
  font-size: clamp(18px, 2vw, 21px);
  line-height: 1.58;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 11px;
  margin-top: 28px;
}

.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
}

.button-primary {
  background: linear-gradient(135deg, var(--blue), var(--violet));
  color: #ffffff;
  box-shadow: 0 10px 24px rgba(66, 72, 223, 0.2);
}

.button-primary:hover {
  color: #ffffff;
  filter: brightness(1.05);
}

.button-secondary {
  border-color: var(--line);
  background: var(--surface);
  color: var(--text);
}

.hero-mark {
  position: relative;
  display: grid;
  min-height: 320px;
  place-items: center;
}

.hero-mark::before {
  position: absolute;
  width: 270px;
  height: 270px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(47, 101, 238, 0.18), rgba(32, 167, 186, 0.14));
  content: "";
}

.app-icon-large {
  position: relative;
  width: min(62vw, 220px);
  filter: drop-shadow(0 28px 38px rgba(38, 43, 84, 0.24));
}

.section {
  padding-block: 60px;
}

.section-heading {
  max-width: 690px;
  margin-bottom: 28px;
}

.section-heading p,
.feature-card p,
.page-intro p,
.site-note,
.document-card p {
  color: var(--muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.feature-card,
.document-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 10px 30px rgba(42, 48, 91, 0.06);
}

.feature-card {
  min-height: 180px;
  padding: 26px;
}

.feature-card p {
  margin: 0;
}

.site-note {
  margin: 22px 0 0;
  font-size: 14px;
}

.page-intro {
  max-width: 760px;
  margin-bottom: 38px;
}

.page-intro h1 {
  margin-bottom: 16px;
  font-size: clamp(40px, 6vw, 58px);
}

.page-intro p {
  margin: 0;
  font-size: 19px;
}

.document-card {
  max-width: 840px;
  padding: clamp(26px, 5vw, 52px);
}

.document-card section + section {
  margin-top: 34px;
  padding-top: 30px;
  border-top: 1px solid var(--line);
}

.document-card h2 {
  font-size: clamp(26px, 3.4vw, 34px);
}

.document-card h3 {
  margin-top: 26px;
}

.document-card p {
  max-width: 72ch;
}

.document-card p + p {
  margin-top: 1em;
}

.document-card ul {
  max-width: 72ch;
  padding-left: 1.35em;
}

.document-card li + li {
  margin-top: 7px;
}

.metadata-list {
  display: grid;
  grid-template-columns: max-content minmax(0, 1fr);
  gap: 7px 18px;
  margin: 22px 0 0;
}

.metadata-list dt {
  color: var(--muted);
  font-weight: 650;
}

.metadata-list dd {
  margin: 0;
  overflow-wrap: anywhere;
}

.callout {
  margin: 24px 0;
  padding: 18px 20px;
  border-left: 4px solid var(--accent);
  border-radius: 0 12px 12px 0;
  background: var(--accent-soft);
}

.callout p {
  margin: 0;
  color: var(--text);
}

.site-footer {
  border-top: 1px solid var(--line);
}

.footer-inner {
  display: flex;
  min-height: 116px;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  color: var(--muted);
  font-size: 14px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
}

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

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

.utility-page {
  display: grid;
  min-height: 100vh;
  place-items: center;
}

.utility-shell {
  width: min(calc(100% - 40px), 650px);
  padding-block: 64px;
}

.utility-card {
  padding: clamp(28px, 7vw, 56px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.utility-card h1 {
  margin-bottom: 16px;
  font-size: clamp(38px, 7vw, 56px);
}

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

@media (max-width: 800px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .hero-mark {
    min-height: 250px;
    order: -1;
  }

  .app-icon-large {
    width: 170px;
  }

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

@media (max-width: 600px) {
  body {
    font-size: 16px;
  }

  .header-inner,
  .page-shell,
  .footer-inner {
    width: min(calc(100% - 28px), var(--content));
  }

  .header-inner {
    min-height: 62px;
  }

  .site-nav a {
    padding-inline: 7px;
    font-size: 13px;
  }

  .page-shell {
    padding-block: 48px 68px;
  }

  .hero-mark {
    min-height: 210px;
  }

  .app-icon-large {
    width: 145px;
  }

  .section {
    padding-block: 48px;
  }

  .feature-card,
  .document-card {
    padding: 23px;
  }

  .metadata-list {
    grid-template-columns: 1fr;
    gap: 2px;
  }

  .metadata-list dd + dt {
    margin-top: 9px;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    padding-block: 26px;
  }
}

@media (max-width: 430px) {
  .brand span {
    display: none;
  }

  .site-nav {
    gap: 1px;
  }

  .site-nav a {
    padding-inline: 5px;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --page: #0e101b;
    --surface: rgba(24, 27, 46, 0.88);
    --surface-solid: #181b2e;
    --text: #f2f3fa;
    --muted: #b1b5c8;
    --line: rgba(214, 218, 240, 0.13);
    --accent: #91a0ff;
    --accent-strong: #b1bbff;
    --accent-soft: rgba(110, 126, 255, 0.13);
    --teal: #39c7d6;
    --focus-ring: #b8c0ff;
    --shadow: 0 18px 54px rgba(0, 0, 0, 0.28);
  }

  body {
    background:
      radial-gradient(circle at 8% 2%, rgba(47, 101, 238, 0.16), transparent 30rem),
      radial-gradient(circle at 94% 16%, rgba(32, 167, 186, 0.1), transparent 26rem),
      var(--page);
  }

  .site-header {
    background: rgba(14, 16, 27, 0.9);
  }

  .app-icon-large {
    filter: drop-shadow(0 28px 38px rgba(0, 0, 0, 0.42));
  }
}

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

@media (forced-colors: active) {
  .gradient-text {
    color: CanvasText;
  }

  .button,
  .feature-card,
  .document-card,
  .utility-card {
    border: 1px solid CanvasText;
  }

  .button-primary {
    background: ButtonFace;
    color: ButtonText;
  }
}