:root {
  --bg: #07080F;
  --bg2: #0C0D18;
  --surface: #181928;
  --border: rgba(255,255,255,0.06);
  --border2: rgba(255,255,255,0.1);
  --blue: #2563EB;
  --blue-light: #3B82F6;
  --white: #F1F0F8;
  --muted: #5A5870;
  --muted2: #8A8898;
  --text: #C8C6D8;
  --sans: 'Instrument Sans', system-ui, sans-serif;
  --r: 14px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  min-height: 100vh;
}

.seo-nav {
  position: sticky; top: 0; z-index: 100;
  padding: 1rem 2rem;
  display: flex; align-items: center; justify-content: space-between;
  background: rgba(7,8,15,0.92);
  backdrop-filter: blur(24px);
  border-bottom: 1px solid var(--border);
}
.seo-logo {
  font-weight: 700; font-size: 1.15rem; color: var(--white);
  text-decoration: none; letter-spacing: -0.02em;
}
.seo-logo span { color: var(--blue-light); }
.seo-nav-right { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }
.seo-nav-link {
  color: var(--muted2); text-decoration: none; font-size: 0.9rem;
  transition: color 0.2s;
}
.seo-nav-link:hover { color: var(--white); }
.seo-lang-switch {
  display: inline-flex; gap: 2px; padding: 2px;
  border: 1px solid var(--border2); border-radius: 8px;
}
.seo-lang-switch a {
  padding: 4px 10px; border-radius: 6px; font-size: 0.75rem;
  font-weight: 600; text-decoration: none; color: var(--muted2);
}
.seo-lang-switch a.active { background: var(--blue); color: #fff; }
.seo-btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 0.55rem 1.1rem; border-radius: 10px; font-weight: 600;
  font-size: 0.875rem; text-decoration: none; border: none; cursor: pointer;
  transition: opacity 0.2s, transform 0.15s;
}
.seo-btn:hover { opacity: 0.92; transform: translateY(-1px); }
.seo-btn-blue { background: var(--blue); color: #fff; }
.seo-btn-outline {
  background: transparent; color: var(--white);
  border: 1px solid var(--border2);
}

.seo-main { max-width: 820px; margin: 0 auto; padding: 3rem 1.5rem 4rem; }
.seo-main.wide { max-width: 960px; }
.seo-eyebrow {
  font-size: 0.75rem; font-weight: 600; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--blue-light); margin-bottom: 0.75rem;
}
.seo-main h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  color: var(--white); line-height: 1.15; letter-spacing: -0.02em;
  margin-bottom: 1rem;
}
.seo-main h1 em { color: var(--blue-light); font-style: normal; }
.seo-lead { font-size: 1.1rem; color: var(--muted2); margin-bottom: 2rem; max-width: 640px; }
.seo-section { margin-bottom: 2.5rem; }
.seo-section h2 {
  font-size: 1.25rem; color: var(--white); margin-bottom: 0.75rem;
}
.seo-section p { margin-bottom: 0.85rem; }
.seo-section ul, .seo-section ol { margin: 0.75rem 0 1rem 1.25rem; }
.seo-section li { margin-bottom: 0.4rem; }

.seo-cards {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem; margin: 2rem 0;
}
.seo-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); padding: 1.25rem;
  text-decoration: none; color: inherit;
  transition: border-color 0.2s, transform 0.15s;
}
.seo-card:hover { border-color: var(--blue); transform: translateY(-2px); }
.seo-card h3 { color: var(--white); font-size: 1rem; margin-bottom: 0.4rem; }
.seo-card p { font-size: 0.875rem; color: var(--muted2); margin: 0; }

.seo-faq { margin-top: 2rem; }
.seo-faq-item {
  border-bottom: 1px solid var(--border); padding: 1rem 0;
}
.seo-faq-item h3 { font-size: 1rem; color: var(--white); margin-bottom: 0.4rem; }
.seo-faq-item p { font-size: 0.925rem; margin: 0; }

.seo-cta {
  margin-top: 3rem; padding: 2rem;
  background: linear-gradient(135deg, rgba(37,99,235,0.12), rgba(6,182,212,0.06));
  border: 1px solid rgba(37,99,235,0.25); border-radius: var(--r);
  text-align: center;
}
.seo-cta h2 { color: var(--white); margin-bottom: 0.5rem; font-size: 1.35rem; }
.seo-cta p { color: var(--muted2); margin-bottom: 1.25rem; }
.seo-cta-btns { display: flex; gap: 0.75rem; justify-content: center; flex-wrap: wrap; }

.seo-breadcrumb {
  font-size: 0.8rem; color: var(--muted); margin-bottom: 1.5rem;
}
.seo-breadcrumb a { color: var(--muted2); text-decoration: none; }
.seo-breadcrumb a:hover { color: var(--blue-light); }

.seo-compare-table {
  width: 100%; border-collapse: collapse; margin: 1.5rem 0;
  font-size: 0.9rem;
}
.seo-compare-table th, .seo-compare-table td {
  border: 1px solid var(--border); padding: 0.75rem 1rem; text-align: left;
}
.seo-compare-table th { background: var(--surface); color: var(--white); }
.seo-compare-table td:first-child { color: var(--white); font-weight: 500; }
.seo-compare-wide { font-size: 0.82rem; }
.seo-compare-wide small { color: var(--muted); font-weight: 400; }

.seo-definition-meta {
  font-size: 0.95rem; color: var(--muted2); margin: 0.5rem 0 1.25rem;
  padding: 0.85rem 1rem; border-left: 3px solid var(--blue);
  background: rgba(37, 99, 235, 0.08); border-radius: 0 var(--r) var(--r) 0;
}
.seo-cite-box {
  margin-top: 2rem; padding: 1.25rem 1.5rem;
  border: 1px solid var(--border2); border-radius: var(--r);
  background: var(--surface);
}
.seo-cite-label {
  font-size: 0.68rem; font-weight: 600; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--muted); margin-bottom: 0.5rem;
}
.seo-cite-box p { margin: 0; font-size: 0.9rem; color: var(--text); }
.seo-cite-box a { color: var(--blue-light); }

.seo-footer {
  border-top: 1px solid var(--border);
  padding: 3rem 2rem 2rem;
  max-width: 1200px; margin: 0 auto;
}
.seo-footer-grid {
  display: grid;
  grid-template-columns: minmax(200px, 1.35fr) repeat(4, 1fr);
  gap: 1.5rem 1.25rem;
  margin-bottom: 2rem;
  align-items: start;
}
.seo-footer-brand-block { grid-row: 1 / span 2; }
.seo-footer-col .seo-footer-links { max-height: 200px; overflow-y: auto; }
.seo-footer-desc a { color: var(--blue-light); text-decoration: none; font-size: 0.85rem; }
.seo-footer-desc a:hover { text-decoration: underline; }
.seo-footer-brand { font-weight: 700; font-size: 1.1rem; color: var(--white); margin-bottom: 0.5rem; }
.seo-footer-desc { font-size: 0.85rem; color: var(--muted); line-height: 1.5; }
.seo-footer-label {
  font-size: 0.7rem; font-weight: 600; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--muted); margin-bottom: 0.75rem;
}
.seo-footer-links { list-style: none; }
.seo-footer-links li { margin-bottom: 0.35rem; }
.seo-footer-links a {
  color: var(--muted2); text-decoration: none; font-size: 0.85rem;
}
.seo-footer-links a:hover { color: var(--white); }
.seo-footer-bottom {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.5rem;
  font-size: 0.8rem; color: var(--muted); padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.seo-404 { text-align: center; padding: 6rem 1.5rem; }
.seo-404 h1 { font-size: 4rem; color: var(--blue-light); margin-bottom: 0.5rem; }
.seo-404 p { color: var(--muted2); margin-bottom: 1.5rem; }

@media (max-width: 640px) {
  .seo-nav { padding: 0.85rem 1rem; }
  .seo-nav-right .seo-nav-link { display: none; }
  .seo-main { padding: 2rem 1rem 3rem; }
  .seo-footer-grid { grid-template-columns: 1fr 1fr; }
  .seo-footer-brand-block { grid-row: auto; grid-column: 1 / -1; }
}
@media (max-width: 480px) {
  .seo-footer-grid { grid-template-columns: 1fr; }
}