:root {
  color-scheme: light;
  --page: #f5f7fb;
  --paper: #ffffff;
  --ink: #0d1117;
  --muted: #5f6f84;
  --line: #dce3ee;
  --accent: #0b63f6;
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  background:
    linear-gradient(90deg, rgb(15 23 42 / 4%) 1px, transparent 1px) 0 0 / 46px 46px,
    radial-gradient(circle at 16% 8%, rgb(11 99 246 / 8%), transparent 380px),
    var(--page);
  color: var(--ink);
  margin: 0;
}

a {
  color: inherit;
}

.seo-header,
.seo-footer {
  align-items: center;
  display: flex;
  justify-content: space-between;
  margin: 0 auto;
  max-width: 1040px;
  padding: 22px 24px;
}

.seo-brand img {
  display: block;
  height: 62px;
  object-fit: contain;
  width: 210px;
}

.seo-header nav,
.seo-footer {
  color: var(--muted);
  font-size: 13px;
}

.seo-header nav {
  display: flex;
  gap: 18px;
}

.seo-header a,
.seo-footer a {
  text-decoration: none;
}

.seo-page {
  margin: 0 auto;
  max-width: 880px;
  padding: 70px 24px 48px;
}

.eyebrow {
  color: var(--accent);
  font-size: 12px;
  font-weight: 820;
  letter-spacing: .18em;
  margin: 0 0 18px;
  text-transform: uppercase;
}

h1 {
  font-size: clamp(42px, 6vw, 72px);
  letter-spacing: 0;
  line-height: 1;
  margin: 0 0 24px;
}

.lead {
  color: #40516a;
  font-size: 21px;
  font-weight: 620;
  line-height: 1.65;
  margin: 0 0 26px;
}

.byline {
  border-bottom: 1px solid var(--line);
  border-top: 1px solid var(--line);
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  font-size: 13px;
  gap: 10px 18px;
  margin: 0 0 44px;
  padding: 14px 0;
}

section,
.note-box,
.related {
  margin: 0 0 38px;
}

h2 {
  font-size: 25px;
  line-height: 1.28;
  margin: 0 0 12px;
}

h3 {
  font-size: 18px;
  margin: 0 0 8px;
}

p,
li {
  color: #46566c;
  font-size: 17px;
  line-height: 1.78;
}

p {
  margin: 0 0 14px;
}

ul,
ol {
  margin: 0;
  padding-left: 1.25em;
}

.note-box,
.related,
.source-box,
.checklist {
  background: rgb(255 255 255 / 88%);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 20px;
}

.source-box {
  margin-top: 30px;
}

.related a {
  border-bottom: 1px solid var(--line);
  display: block;
  padding: 10px 0;
  text-decoration: none;
}

.related a:last-child {
  border-bottom: 0;
}

.cta {
  background: #0f172a;
  border-radius: 8px;
  color: #fff;
  margin-top: 46px;
  padding: 26px;
}

.cta p {
  color: #d8e2f0;
}

.cta a {
  background: var(--accent);
  border-radius: 8px;
  display: inline-flex;
  font-weight: 800;
  margin-top: 12px;
  min-height: 44px;
  padding: 11px 16px;
  text-decoration: none;
}

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

.guide-grid a {
  background: rgb(255 255 255 / 88%);
  border: 1px solid var(--line);
  border-radius: 8px;
  display: grid;
  gap: 7px;
  padding: 16px;
  text-decoration: none;
}

.guide-grid span {
  color: var(--muted);
  font-size: 13px;
}

.seo-footer {
  border-top: 1px solid var(--line);
  margin-top: 40px;
}

.seo-footer p {
  color: var(--muted);
  font-size: 13px;
  margin: 0;
}

@media (max-width: 680px) {
  .seo-header,
  .seo-footer {
    align-items: flex-start;
    display: grid;
    gap: 12px;
  }

  .seo-brand img {
    height: 52px;
    width: 170px;
  }

  .seo-page {
    padding-top: 42px;
  }

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