:root {
  color-scheme: dark;
  --bg: #0b1724;
  --panel: #102338;
  --ink: #f2f7fb;
  --muted: #b2c2d0;
  --blue: #8bd4ff;
  --border: rgba(174, 204, 228, .16);
}

* { box-sizing: border-box }
html { scroll-behavior: smooth }
body {
  margin: 0;
  background: radial-gradient(ellipse at 50% 0, rgba(75, 159, 225, .18), transparent 38rem), var(--bg);
  color: var(--ink);
  font: 17px/1.75 system-ui, -apple-system, "Segoe UI", sans-serif;
}
a { color: var(--blue); text-underline-offset: 3px }
a:hover { color: #c6ebff }
.wrap { width: min(900px, calc(100% - 36px)); margin: 0 auto }
.top { border-bottom: 1px solid var(--border); background: rgba(11, 23, 36, .85) }
.top .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 17px 0 }
.brand { color: var(--ink); font-weight: 750; text-decoration: none }
.back { font-size: 14px }
main { padding: 52px 0 76px }
.eyebrow { color: var(--blue); font-size: 13px; font-weight: 700; letter-spacing: .09em; text-transform: uppercase }
h1 { max-width: 820px; margin: 10px 0 14px; font-size: clamp(34px, 6vw, 54px); line-height: 1.08; letter-spacing: -.035em }
h2 { margin: 42px 0 12px; font-size: clamp(24px, 4vw, 31px); line-height: 1.2 }
h3 { margin: 24px 0 8px; font-size: 20px }
.lead { max-width: 760px; color: var(--muted); font-size: 20px; line-height: 1.55 }
.byline { color: var(--muted); font-size: 14px }
p, li { color: #d5e1ea }
li { margin: 8px 0 }
.toc, .note, .cta, .guide-card { border: 1px solid var(--border); border-radius: 15px; background: rgba(16, 35, 56, .78) }
.toc { margin: 28px 0; padding: 20px 24px }
.toc strong { display: block; margin-bottom: 5px }
.toc ul { margin: 8px 0 0; padding-left: 20px }
.note { margin: 22px 0; padding: 17px 20px }
.note strong { color: var(--ink) }
pre { overflow: auto; margin: 20px 0; padding: 20px; border: 1px solid var(--border); border-radius: 12px; background: #07111c; color: #dcecf8; font: 14px/1.7 ui-monospace, SFMono-Regular, Consolas, monospace; tab-size: 4 }
code { color: #a9ddff; font: .92em ui-monospace, SFMono-Regular, Consolas, monospace }
.cta { margin: 42px 0 0; padding: 24px; background: linear-gradient(135deg, rgba(75, 159, 225, .15), rgba(16, 35, 56, .88)) }
.cta p { margin: 7px 0 15px; color: var(--muted) }
.button { display: inline-block; padding: 11px 18px; border-radius: 10px; background: linear-gradient(115deg, #287fbe, #56b1e8 70%, #8acbf1); color: #071522; font-size: 15px; font-weight: 750; text-decoration: none }
.button:hover { color: #071522; filter: brightness(1.08) }
.related { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; margin-top: 32px }
.guide-card { display: block; padding: 19px; color: var(--ink); text-decoration: none; transition: transform .2s, border-color .2s }
.guide-card:hover { transform: translateY(-3px); border-color: rgba(139, 212, 255, .48); color: var(--ink) }
.guide-card span { display: block; margin-top: 6px; color: var(--muted); font-size: 14px }
footer { padding: 23px 0 40px; border-top: 1px solid var(--border); color: var(--muted); font-size: 14px }
footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px }
[id] { scroll-margin-top: 20px }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important } }