:root {
  color-scheme: light dark;
  --bg: #f8faff;
  --surface: rgba(255, 255, 255, 0.82);
  --surface-solid: #ffffff;
  --surface-muted: #f1f5ff;
  --text: #111827;
  --text-secondary: #5b6474;
  --separator: rgba(31, 41, 55, 0.12);
  --accent: #335cff;
  --accent-strong: #2146dd;
  --accent-soft: rgba(51, 92, 255, 0.1);
  --shadow: 0 18px 48px rgba(35, 61, 130, 0.1);
  --radius-md: 15px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #080b12;
    --surface: rgba(20, 25, 36, 0.84);
    --surface-solid: #141924;
    --surface-muted: #171d2b;
    --text: #f4f7fb;
    --text-secondary: #a5adba;
    --separator: rgba(255, 255, 255, 0.13);
    --accent: #8096ff;
    --accent-strong: #a5b4ff;
    --accent-soft: rgba(128, 150, 255, 0.15);
    --shadow: 0 20px 54px rgba(0, 0, 0, 0.28);
  }
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.68;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 0%, rgba(51, 92, 255, 0.11), transparent 34rem),
    radial-gradient(circle at 92% 18%, rgba(0, 184, 217, 0.08), transparent 30rem),
    var(--bg);
}

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

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

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

a:focus-visible {
  outline: 3px solid var(--accent);
  outline: 3px solid color-mix(in srgb, var(--accent) 55%, transparent);
  outline-offset: 3px;
  border-radius: 6px;
}

.skip-link {
  position: fixed;
  z-index: 20;
  top: 12px;
  left: 12px;
  padding: 9px 14px;
  border-radius: 9px;
  background: var(--surface-solid);
  color: var(--text);
  box-shadow: var(--shadow);
  transform: translateY(-160%);
}

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

.wrap {
  width: calc(100% - 40px);
  max-width: 920px;
  margin: 0 auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 92px;
  padding: 20px 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: var(--text);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.brand img {
  width: 42px;
  height: 42px;
  border: 1px solid var(--separator);
  border-radius: 11px;
  box-shadow: 0 7px 18px rgba(40, 74, 160, 0.13);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.site-nav a {
  padding: 8px 10px;
  border-radius: 9px;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
}

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

main {
  padding: 42px 0 34px;
}

.hero {
  padding: 48px 0 34px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--accent-strong);
  font-size: 14px;
  font-weight: 750;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  color: var(--text);
  line-height: 1.2;
  letter-spacing: -0.025em;
}

h1 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(2.45rem, 7vw, 4.8rem);
  letter-spacing: -0.055em;
}

h2 {
  margin: 64px 0 18px;
  font-size: clamp(1.65rem, 4vw, 2.15rem);
}

h3 {
  margin: 0 0 8px;
  font-size: 1.1rem;
  letter-spacing: -0.012em;
}

p,
li {
  color: var(--text);
}

.lead {
  max-width: 720px;
  margin: 24px 0 0;
  color: var(--text-secondary);
  font-size: clamp(1.08rem, 2.8vw, 1.35rem);
  line-height: 1.55;
}

.zh-line {
  display: block;
  margin-top: 7px;
  font-size: 0.9em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 11px 18px;
  border: 1px solid var(--separator);
  border-radius: 12px;
  color: var(--text);
  background: var(--surface);
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 8px 22px rgba(29, 52, 112, 0.06);
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.button.primary {
  border-color: transparent;
  color: #ffffff;
  background: linear-gradient(120deg, #3f42f6, #087ff5 60%, #00aeca);
  box-shadow: 0 12px 28px rgba(45, 89, 235, 0.25);
}

.button:hover {
  color: var(--text);
  border-color: color-mix(in srgb, var(--accent) 45%, var(--separator));
  transform: translateY(-1px);
}

.button.primary:hover {
  color: #ffffff;
}

.fact-list {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
}

.fact-list li {
  padding: 7px 11px;
  border: 1px solid var(--separator);
  border-radius: 999px;
  color: var(--text-secondary);
  background: var(--surface);
  font-size: 14px;
  font-weight: 650;
}

.section-intro {
  max-width: 690px;
  margin: -8px 0 24px;
  color: var(--text-secondary);
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.panel,
.card,
.callout {
  border: 1px solid var(--separator);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.panel {
  min-height: 180px;
  padding: 23px;
  border-radius: var(--radius-md);
}

.panel .number {
  display: inline-grid;
  width: 30px;
  height: 30px;
  margin-bottom: 28px;
  place-items: center;
  border-radius: 9px;
  color: var(--accent-strong);
  background: var(--accent-soft);
  font-size: 13px;
  font-weight: 800;
}

.panel p,
.card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.58;
}

.resource-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.card {
  display: flex;
  min-height: 145px;
  padding: 22px;
  flex-direction: column;
  justify-content: space-between;
  border-radius: var(--radius-md);
  color: var(--text);
  transition: border-color 160ms ease;
}

.card:focus-within {
  border-color: color-mix(in srgb, var(--accent) 45%, var(--separator));
}

.card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.card-links {
  display: flex;
  gap: 8px;
  margin-top: 20px;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 700;
}

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

.card-links a:hover {
  text-decoration: underline;
}

.document {
  max-width: 760px;
  margin: 0 auto;
  padding-top: 34px;
}

.document h1 {
  font-size: clamp(2.2rem, 6vw, 3.7rem);
}

.document h2 {
  margin-top: 52px;
  font-size: 1.55rem;
}

.document h3 {
  margin-top: 0;
  font-size: 1.12rem;
}

.document p,
.document li {
  line-height: 1.72;
}

.document ul,
.document ol {
  padding-left: 24px;
}

.document li {
  margin: 7px 0;
}

.updated {
  margin: 12px 0 28px;
  color: var(--text-secondary);
  font-size: 14px;
}

.language-switch {
  display: inline-flex;
  gap: 7px;
  margin-bottom: 24px;
  padding: 6px 9px;
  border: 1px solid var(--separator);
  border-radius: 9px;
  color: var(--text-secondary);
  background: var(--surface);
  font-size: 14px;
}

.language-switch a {
  text-decoration: none;
}

.callout {
  margin: 28px 0;
  padding: 22px 24px;
  border-radius: var(--radius-md);
  border-left: 4px solid var(--accent);
}

.callout p:first-child {
  margin-top: 0;
}

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

.faq-list {
  display: grid;
  gap: 12px;
  margin-top: 24px;
}

.faq-item {
  padding: 22px 24px;
  border: 1px solid var(--separator);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.faq-item p {
  margin: 9px 0 0;
  color: var(--text-secondary);
}

code {
  padding: 0.12em 0.35em;
  border-radius: 5px;
  color: var(--text);
  background: var(--surface-muted);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.88em;
}

footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-top: 56px;
  padding: 28px 0 48px;
  border-top: 1px solid var(--separator);
  color: var(--text-secondary);
  font-size: 13px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

footer a {
  color: var(--text-secondary);
}

@media (max-width: 720px) {
  .wrap {
    width: calc(100% - 32px);
  }

  .site-header {
    align-items: flex-start;
    min-height: auto;
    padding: 18px 0;
    flex-direction: column;
    gap: 14px;
  }

  .site-nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .site-nav a {
    white-space: nowrap;
  }

  main {
    padding-top: 24px;
  }

  .hero {
    padding-top: 28px;
  }

  .grid,
  .resource-grid {
    grid-template-columns: 1fr;
  }

  .panel {
    min-height: auto;
  }

  .panel .number {
    margin-bottom: 18px;
  }

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

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

  .button,
  .card {
    transition: none;
  }

  .button:hover {
    transform: none;
  }
}

@media print {
  :root {
    color-scheme: light;
    --bg: #ffffff;
    --surface: #ffffff;
    --surface-solid: #ffffff;
    --surface-muted: #f3f4f6;
    --text: #000000;
    --text-secondary: #333333;
    --separator: #b8b8b8;
    --accent: #000000;
    --accent-strong: #000000;
    --accent-soft: #eeeeee;
    --shadow: none;
  }

  body {
    color: #000000;
    background: #ffffff;
  }

  .skip-link,
  .site-nav,
  .language-switch,
  .hero-actions {
    display: none;
  }

  .wrap,
  .document {
    width: 100%;
    max-width: none;
    margin: 0;
  }

  .site-header {
    min-height: auto;
    padding: 0 0 24px;
  }

  .brand img,
  .panel,
  .card,
  .callout {
    box-shadow: none;
  }

  main {
    padding: 0;
  }

  a {
    color: inherit;
  }

  footer {
    margin-top: 32px;
    padding-bottom: 0;
  }
}