:root {
  --seo-bg: #0b0f1a;
  --seo-surface: #151b2b;
  --seo-border: #2a3554;
  --seo-text: #e8edff;
  --seo-muted: #a8b3d1;
  --seo-accent: #65d6ff;
  --seo-accent-soft: rgba(101, 214, 255, 0.18);
  --seo-success: #8bf0c4;
}

* {
  box-sizing: border-box;
}

body.seo-foundation-page {
  margin: 0;
  font-family: "Inter", "Segoe UI", Arial, sans-serif;
  background: radial-gradient(circle at top, #141c33 0%, #0b0f1a 48%, #070a13 100%);
  color: var(--seo-text);
  line-height: 1.65;
}

.seo-shell {
  width: min(980px, calc(100% - 2.5rem));
  margin: 0 auto;
}

.seo-topbar {
  position: sticky;
  top: 0;
  backdrop-filter: blur(8px);
  background: rgba(11, 15, 26, 0.78);
  border-bottom: 1px solid rgba(101, 214, 255, 0.2);
  z-index: 10;
}

.seo-topbar .seo-shell {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 0;
}

.seo-brand {
  color: var(--seo-text);
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.seo-nav {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.seo-nav a {
  color: var(--seo-muted);
  text-decoration: none;
  font-size: 0.92rem;
}

.seo-nav a:hover,
.seo-nav a:focus {
  color: var(--seo-accent);
}

.seo-main {
  padding: 2rem 0 3.25rem;
}

.seo-card {
  background: rgba(21, 27, 43, 0.85);
  border: 1px solid var(--seo-border);
  border-radius: 16px;
  padding: 1.5rem;
  margin-bottom: 1rem;
}

.seo-card h2,
.seo-card h3 {
  margin-top: 0;
}

.seo-kicker {
  color: var(--seo-success);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 0 0 0.65rem;
}

.seo-page-title {
  margin: 0 0 0.65rem;
  line-height: 1.25;
  font-size: clamp(1.6rem, 2.4vw, 2.3rem);
}

.seo-summary {
  font-size: 1.05rem;
  color: #d4defa;
}

.seo-last-updated {
  display: inline-block;
  margin-top: 0.75rem;
  color: var(--seo-muted);
  font-size: 0.9rem;
}

.seo-breadcrumbs {
  margin: 0 0 1rem;
  color: var(--seo-muted);
  font-size: 0.9rem;
}

.seo-breadcrumbs a {
  color: var(--seo-muted);
}

.seo-list,
.seo-citation-list,
.seo-links {
  padding-left: 1.1rem;
}

.seo-list li,
.seo-citation-list li,
.seo-links li {
  margin-bottom: 0.5rem;
}

.seo-citation-list a,
.seo-links a,
.seo-inline-link {
  color: var(--seo-accent);
}

.seo-grid {
  display: grid;
  gap: 1rem;
}

@media (min-width: 820px) {
  .seo-grid.two-col {
    grid-template-columns: 1fr 1fr;
  }
}

.seo-faq-item {
  border-top: 1px solid var(--seo-border);
  padding-top: 0.8rem;
  margin-top: 0.8rem;
}

.seo-cta {
  background: linear-gradient(145deg, rgba(101, 214, 255, 0.16), rgba(139, 240, 196, 0.11));
  border-color: rgba(101, 214, 255, 0.4);
}

.seo-cta a {
  display: inline-block;
  margin-top: 0.8rem;
  background: var(--seo-accent-soft);
  color: #dff8ff;
  border: 1px solid rgba(101, 214, 255, 0.45);
  border-radius: 999px;
  text-decoration: none;
  padding: 0.48rem 0.95rem;
  font-weight: 600;
}

.seo-footer {
  border-top: 1px solid var(--seo-border);
  padding: 1.4rem 0 2.2rem;
  color: var(--seo-muted);
  font-size: 0.9rem;
}