:root {
  color-scheme: light dark;
  --seo-bg: #f3f6fb;
  --seo-surface: #fff;
  --seo-ink: #172033;
  --seo-muted: #526078;
  --seo-border: #d9e1ef;
  --seo-link: #155eef;
  --seo-accent: #eaf1ff;
  font-family: "Plus Jakarta Sans", system-ui, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --seo-bg: #0b1020;
    --seo-surface: #111a2c;
    --seo-ink: #eff4ff;
    --seo-muted: #b0bdd2;
    --seo-border: #26334b;
    --seo-link: #84b5ff;
    --seo-accent: #172847;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--seo-ink);
  background: var(--seo-bg);
  line-height: 1.7;
}

a { color: var(--seo-link); text-underline-offset: .18em; }
a:hover { text-decoration-thickness: 2px; }

.skip-link {
  position: absolute;
  top: .5rem;
  left: .5rem;
  z-index: 5;
  padding: .55rem .8rem;
  color: #fff;
  background: #155eef;
  border-radius: .45rem;
  transform: translateY(-160%);
}
.skip-link:focus { transform: translateY(0); }

.site-header,
.site-footer {
  width: min(100% - 2rem, 980px);
  margin-inline: auto;
}

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1.2rem 0;
}
.site-brand { color: var(--seo-ink); font-weight: 800; text-decoration: none; }

.page-shell { width: min(100% - 2rem, 880px); margin: 1rem auto 3rem; }
.seo-home-fallback {
  width: min(100%, 880px);
  margin: 2rem auto;
  padding: clamp(1.2rem, 4vw, 2.2rem);
  color: var(--seo-ink);
  background: var(--seo-surface);
  border: 1px solid var(--seo-border);
  border-radius: 1rem;
  line-height: 1.7;
}
.seo-home-fallback h1 { font-size: clamp(1.7rem, 5vw, 2.5rem); }
.seo-home-fallback a { color: var(--seo-link); }
.breadcrumbs { display: flex; flex-wrap: wrap; gap: .55rem; color: var(--seo-muted); font-size: .9rem; margin: 0 0 1rem; }
.breadcrumbs a { color: var(--seo-muted); }

.guide-card {
  padding: clamp(1.2rem, 4vw, 2.5rem);
  background: var(--seo-surface);
  border: 1px solid var(--seo-border);
  border-radius: 1rem;
  box-shadow: 0 12px 34px rgb(18 34 61 / 7%);
}

h1, h2, h3 { line-height: 1.25; }
h1 { margin: 0 0 1rem; font-size: clamp(1.8rem, 5vw, 2.7rem); letter-spacing: -.035em; }
h2 { margin: 2rem 0 .6rem; font-size: clamp(1.2rem, 3vw, 1.55rem); }
.lead { margin: 0 0 1.8rem; color: var(--seo-muted); font-size: 1.1rem; }
.guide-section p, .example-box p { max-width: 72ch; }
.guide-section + .guide-section { border-top: 1px solid var(--seo-border); margin-top: 1.7rem; padding-top: .35rem; }

.example-box, .usage-note {
  margin-top: 1.8rem;
  padding: 1rem 1.15rem;
  background: var(--seo-accent);
  border-radius: .75rem;
}
.example-box h2 { margin-top: 0; }
.example-box p { margin-bottom: 0; }
.usage-note { border-left: 4px solid var(--seo-link); }

.related-tools ul, .guide-list { padding-left: 1.25rem; }
.related-tools li, .guide-list li { margin: .55rem 0; }
.primary-action {
  display: inline-flex;
  margin-top: 1.5rem;
  padding: .75rem 1.1rem;
  color: #fff;
  background: #155eef;
  border-radius: .65rem;
  font-weight: 700;
  text-decoration: none;
}
.primary-action:hover { background: #0e4dc9; text-decoration: underline; }
.guide-list { list-style: none; padding: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); gap: .9rem; }
.guide-list-card { margin: 0 !important; }
.guide-list-card a { display: block; height: 100%; padding: 1rem; background: var(--seo-bg); border: 1px solid var(--seo-border); border-radius: .75rem; text-decoration: none; }
.guide-list-card a:hover { border-color: var(--seo-link); }
.guide-list-card h2 { margin: 0 0 .5rem; color: var(--seo-ink); font-size: 1.05rem; }
.guide-list-card p { margin: 0; color: var(--seo-muted); font-size: .95rem; }

.site-footer { padding: 1.2rem 0 2rem; color: var(--seo-muted); font-size: .9rem; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: .6rem 1rem; }
.site-footer nav a { color: var(--seo-muted); }

@media (max-width: 520px) {
  .site-header { align-items: flex-start; flex-direction: column; }
  .guide-card { border-radius: .75rem; }
}

@media print {
  :root { color-scheme: light; --seo-bg: #fff; --seo-surface: #fff; --seo-ink: #000; --seo-muted: #333; --seo-border: #bbb; }
  .site-header, .site-footer, .primary-action { display: none; }
  .guide-card { box-shadow: none; border: 0; padding: 0; }
}