:root {
  color-scheme: dark;
  --bg: #05050d;
  --panel: #0c0e18;
  --panel-2: #111522;
  --text: #f7f8fb;
  --muted: #aeb4c0;
  --line: rgba(255, 255, 255, .12);
  --blue: #6ecff6;
  --max: 1080px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at 75% 0%, rgba(43, 111, 255, .18), transparent 34rem),
    var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

.container {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--line);
  background: rgba(5, 5, 13, .86);
  backdrop-filter: blur(18px);
}

.nav {
  display: flex;
  min-height: 68px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand,
.nav-links,
.button {
  display: inline-flex;
  align-items: center;
}

.brand {
  gap: 10px;
  text-decoration: none;
  font-weight: 750;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 10px;
}

.nav-links {
  gap: 18px;
}

.nav-links a,
.site-footer a {
  color: var(--muted);
  text-decoration: none;
}

.nav-links a:hover,
.site-footer a:hover {
  color: #fff;
}

.button {
  min-height: 42px;
  justify-content: center;
  border-radius: 999px;
  padding: 0 18px;
  background: #fff;
  color: #070812;
  font-weight: 750;
  text-decoration: none;
}

.breadcrumbs {
  padding-top: 46px;
  color: var(--muted);
  font-size: 14px;
}

.breadcrumbs a {
  color: var(--blue);
  text-decoration: none;
}

.hero {
  padding: 34px 0 48px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  color: var(--blue);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: .12em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  letter-spacing: -.02em;
  line-height: 1.28;
}

h1 {
  max-width: 820px;
  margin: 14px 0 18px;
  font-size: clamp(36px, 6vw, 68px);
}

.lead {
  max-width: 780px;
  margin: 0;
  color: var(--muted);
  font-size: 19px;
}

.meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 22px;
  margin-top: 24px;
  color: #878e9c;
  font-size: 14px;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 54px;
  padding: 54px 0 72px;
}

article h2 {
  margin: 46px 0 14px;
  font-size: 29px;
}

article h2:first-child {
  margin-top: 0;
}

article h3 {
  margin: 28px 0 8px;
  font-size: 21px;
}

article p,
article li {
  color: #d5d8df;
}

article ul,
article ol {
  padding-left: 22px;
}

.callout,
.checklist,
.related {
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--panel);
}

.callout {
  margin: 26px 0;
  padding: 20px 22px;
  color: #dfeaf0;
}

.callout strong {
  color: var(--blue);
}

.checklist {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  overflow: hidden;
  margin: 24px 0;
  background: var(--line);
}

.checklist > div {
  padding: 20px;
  background: var(--panel);
}

.checklist strong {
  display: block;
  margin-bottom: 5px;
}

.checklist span {
  color: var(--muted);
}

.toc {
  position: sticky;
  top: 98px;
  align-self: start;
  border-left: 1px solid var(--line);
  padding-left: 22px;
}

.toc strong {
  display: block;
  margin-bottom: 12px;
}

.toc a {
  display: block;
  padding: 7px 0;
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.toc a:hover {
  color: #fff;
}

.related {
  margin-top: 52px;
  padding: 24px;
}

.related h2 {
  margin-top: 0;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.related-grid a {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px;
  color: #fff;
  text-decoration: none;
}

.related-grid a:hover {
  border-color: rgba(110, 207, 246, .55);
}

.source-link {
  color: var(--blue);
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 30px 0 48px;
}

.footer-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

@media (max-width: 780px) {
  .nav-links {
    display: none;
  }

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

  .toc {
    display: none;
  }

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

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