:root {
  color-scheme: light dark;
  --background: #f6f7f5;
  --surface: #ffffff;
  --surface-alt: #eef2ef;
  --border: #d8ded9;
  --border-strong: #b8c2bb;
  --text: #18201c;
  --text-secondary: #5e6a63;
  --brand: #2f7d6d;
  --brand-hover: #286a5d;
  --brand-subtle: #ddede8;
  --success: #247a4d;
  --warning: #865900;
  --danger: #a73333;
  --focus: #2f7d6d;
  --shadow: 0 1px 2px rgb(17 21 19 / 8%);
  --page: 72rem;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei UI", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  font-synthesis: none;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: var(--background);
  font-size: 1rem;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}
a { color: var(--brand); text-underline-offset: .18em; }
a:hover { color: var(--brand-hover); }
a:focus-visible, summary:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: .25rem;
}
img, svg { max-width: 100%; }
code {
  padding: .12rem .35rem;
  border: 1px solid var(--border);
  border-radius: .35rem;
  background: var(--surface-alt);
  font: .88em/1.5 "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  overflow-wrap: anywhere;
}
pre {
  margin: 1rem 0;
  padding: 1rem;
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: .75rem;
  background: var(--surface-alt);
}
pre code { padding: 0; border: 0; background: transparent; }

.skip-link {
  position: fixed;
  z-index: 100;
  top: .5rem;
  left: .5rem;
  padding: .65rem 1rem;
  border-radius: .5rem;
  color: #fff;
  background: var(--brand);
  transform: translateY(-160%);
}
.skip-link:focus { transform: translateY(0); }
.site-header {
  position: sticky;
  z-index: 10;
  top: 0;
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--background) 92%, transparent);
  backdrop-filter: blur(12px);
}
.nav-shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  width: min(100% - 2rem, var(--page));
  min-height: 4rem;
  margin-inline: auto;
}
.brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: .6rem;
  color: var(--text);
  font-size: 1.1rem;
  font-weight: 700;
  text-decoration: none;
}
.brand-mark {
  display: grid;
  width: 2rem;
  height: 2rem;
  place-items: center;
  border-radius: .65rem;
  color: #fff;
  background: var(--brand);
  font-size: .92rem;
}
.site-nav ul {
  display: flex;
  align-items: center;
  gap: .25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.site-nav a {
  display: inline-flex;
  min-height: 2.5rem;
  align-items: center;
  padding: .35rem .75rem;
  border-radius: .5rem;
  color: var(--text-secondary);
  font-size: .94rem;
  font-weight: 600;
  text-decoration: none;
}
.site-nav a:hover { color: var(--text); background: var(--surface-alt); }
.site-nav a[aria-current="page"] { color: var(--brand); background: var(--brand-subtle); }

main { min-height: 65vh; }
.container { width: min(100% - 2rem, var(--page)); margin-inline: auto; }
.hero { padding: clamp(4rem, 9vw, 7.5rem) 0 4rem; }
.hero-grid { display: grid; grid-template-columns: 1.2fr .8fr; align-items: center; gap: 3rem; }
.eyebrow {
  margin: 0 0 .75rem;
  color: var(--brand);
  font-size: .85rem;
  font-weight: 700;
  letter-spacing: .08em;
}
h1, h2, h3 { margin-top: 0; line-height: 1.3; text-wrap: balance; }
h1 { max-width: 15ch; margin-bottom: 1.25rem; font-size: clamp(2.25rem, 6vw, 4.5rem); letter-spacing: -.04em; }
h2 { margin-bottom: 1rem; font-size: clamp(1.75rem, 4vw, 2.5rem); letter-spacing: -.025em; }
h3 { margin-bottom: .5rem; font-size: 1.18rem; }
.lead { max-width: 44rem; margin: 0; color: var(--text-secondary); font-size: clamp(1.08rem, 2.3vw, 1.3rem); }
.actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.75rem; }
.button {
  display: inline-flex;
  min-height: 2.75rem;
  align-items: center;
  justify-content: center;
  padding: .55rem 1rem;
  border: 1px solid var(--border-strong);
  border-radius: .55rem;
  color: var(--text);
  background: var(--surface);
  font-weight: 650;
  text-decoration: none;
}
.button:hover { color: var(--text); border-color: var(--brand); background: var(--surface-alt); }
.button.primary { color: #fff; border-color: var(--brand); background: var(--brand); }
.button.primary:hover { color: #fff; border-color: var(--brand-hover); background: var(--brand-hover); }
.button.full { width: 100%; }
.hero-panel {
  padding: 1.5rem;
  border: 1px solid var(--border);
  border-radius: 1rem;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.hero-panel ol { margin: 0; padding: 0; list-style: none; counter-reset: item; }
.hero-panel li { display: grid; grid-template-columns: 2rem 1fr; gap: .75rem; padding: .85rem 0; border-bottom: 1px solid var(--border); }
.hero-panel li:last-child { border-bottom: 0; }
.hero-panel li::before {
  display: grid;
  width: 1.75rem;
  height: 1.75rem;
  place-items: center;
  border-radius: 999px;
  color: var(--brand);
  background: var(--brand-subtle);
  font-weight: 700;
  content: counter(item);
  counter-increment: item;
}

.section { padding: clamp(3.5rem, 7vw, 5.5rem) 0; }
.section.alt { border-block: 1px solid var(--border); background: var(--surface-alt); }
.section-heading { max-width: 46rem; margin-bottom: 2rem; }
.section-heading p { color: var(--text-secondary); }
.grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card {
  padding: 1.4rem;
  border: 1px solid var(--border);
  border-radius: .8rem;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.card p:last-child, .card ul:last-child { margin-bottom: 0; }
.card p, .muted { color: var(--text-secondary); }
.card-icon {
  display: grid;
  width: 2.4rem;
  height: 2.4rem;
  margin-bottom: 1rem;
  place-items: center;
  border-radius: .65rem;
  color: var(--brand);
  background: var(--brand-subtle);
  font-weight: 800;
}
.list-clean { margin: 0; padding: 0; list-style: none; }
.list-clean li { padding: .55rem 0; border-bottom: 1px solid var(--border); }
.list-clean li:last-child { border-bottom: 0; }
.check-list { padding-left: 1.3rem; }
.check-list li { margin: .5rem 0; }
.notice {
  padding: 1rem 1.2rem;
  border: 1px solid var(--border);
  border-left: .3rem solid var(--brand);
  border-radius: .5rem;
  background: var(--surface);
}
.notice.warning { border-left-color: var(--warning); }
.notice strong { display: block; margin-bottom: .2rem; }
.page-intro { padding: clamp(3.5rem, 7vw, 5.5rem) 0 3rem; }
.page-intro h1 { max-width: 18ch; font-size: clamp(2.3rem, 5vw, 3.7rem); }
.toc { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: 1.5rem; }
.toc a { padding: .35rem .7rem; border: 1px solid var(--border); border-radius: 999px; background: var(--surface); text-decoration: none; }

.download-grid { margin-top: 1.25rem; }
.download-card { display: flex; flex-direction: column; }
.platform { color: var(--brand); font-size: .82rem; font-weight: 800; letter-spacing: .07em; }
.download-card .button { margin-top: auto; }
.asset-name { display: block; margin: .75rem 0 1.1rem; color: var(--text-secondary); font-size: .82rem; }
.steps { counter-reset: steps; padding: 0; list-style: none; }
.steps li { position: relative; min-height: 3rem; padding: 0 0 1.5rem 3.2rem; }
.steps li::before {
  position: absolute;
  left: 0;
  display: grid;
  width: 2.2rem;
  height: 2.2rem;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--brand);
  background: var(--surface);
  font-weight: 800;
  content: counter(steps);
  counter-increment: steps;
}
.faq-list { display: grid; gap: .75rem; }
details { border: 1px solid var(--border); border-radius: .7rem; background: var(--surface); }
summary { padding: 1rem 3rem 1rem 1.1rem; cursor: pointer; font-weight: 700; }
details > div { padding: 0 1.1rem 1.1rem; color: var(--text-secondary); }
details p:first-child { margin-top: 0; }

.site-footer { padding: 2.5rem 0; border-top: 1px solid var(--border); background: var(--surface); }
.footer-grid { display: flex; align-items: flex-start; justify-content: space-between; gap: 2rem; }
.footer-grid p { max-width: 42rem; margin: 0; color: var(--text-secondary); font-size: .9rem; }
.footer-links { display: flex; flex-wrap: wrap; gap: .75rem 1.1rem; margin: 0; padding: 0; list-style: none; }
.footer-links a { white-space: nowrap; }

@media (prefers-color-scheme: dark) {
  :root {
    --background: #111513;
    --surface: #191f1c;
    --surface-alt: #222a26;
    --border: #35413a;
    --border-strong: #4a5a51;
    --text: #eef3f0;
    --text-secondary: #aeb3b0;
    --brand: #65b7a2;
    --brand-hover: #7ac5b1;
    --brand-subtle: #203d35;
    --success: #57b983;
    --warning: #e1aa43;
    --danger: #e77575;
    --focus: #7ac5b1;
  }
  .button.primary { color: #10201a; }
}
@media (max-width: 56rem) {
  .nav-shell { align-items: flex-start; flex-direction: column; gap: .4rem; padding-block: .75rem; }
  .site-header { position: static; }
  .site-nav { width: 100%; overflow-x: auto; }
  .site-nav ul { width: max-content; }
  .hero-grid, .grid, .grid.two { grid-template-columns: 1fr; }
  .hero-panel { max-width: 38rem; }
}
@media (max-width: 40rem) {
  .container, .nav-shell { width: min(100% - 1.25rem, var(--page)); }
  .site-nav a { padding-inline: .55rem; }
  .hero { padding-top: 3rem; }
  .footer-grid { flex-direction: column; }
  .actions .button { width: 100%; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .001ms !important; animation-duration: .001ms !important; animation-iteration-count: 1 !important; }
}
@media (forced-colors: active) {
  .button, .card, .notice, details { border: 1px solid CanvasText; }
}