:root {
  --bg-start: #0f172a;
  --bg-mid: #1e293b;
  --bg-end: #334155;
  --surface: rgba(255, 255, 255, 0.05);
  --surface-strong: rgba(255, 255, 255, 0.08);
  --border: rgba(255, 255, 255, 0.12);
  --text-main: #f8fafc;
  --text-soft: rgba(248, 250, 252, 0.78);
  --text-muted: rgba(248, 250, 252, 0.58);
  --blue: #3b82f6;
  --blue-deep: #2563eb;
  --violet: #8b5cf6;
  --violet-deep: #7c3aed;
  --green: #22c55e;
  --amber: #f59e0b;
  --shadow: 0 24px 70px rgba(2, 6, 23, 0.38);
  --radius-xl: 28px;
  --radius-lg: 22px;
  --radius-md: 16px;
  --max-width: 1200px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background:
    radial-gradient(circle at top left, rgba(59, 130, 246, 0.18), transparent 34%),
    radial-gradient(circle at top right, rgba(139, 92, 246, 0.16), transparent 30%),
    linear-gradient(135deg, var(--bg-start) 0%, var(--bg-mid) 50%, var(--bg-end) 100%);
  color: var(--text-main);
  min-height: 100vh;
  overflow-x: hidden;
}

a {
  color: inherit;
}

img {
  max-width: 100%;
  display: block;
}

.seo-shell {
  position: relative;
}

.seo-shell::before,
.seo-shell::after {
  content: '';
  position: fixed;
  inset: auto;
  width: 420px;
  height: 420px;
  border-radius: 999px;
  pointer-events: none;
  filter: blur(90px);
  opacity: 0.18;
  z-index: 0;
}

.seo-shell::before {
  top: -140px;
  left: -120px;
  background: #3b82f6;
}

.seo-shell::after {
  right: -120px;
  bottom: 10%;
  background: #8b5cf6;
}

.seo-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(15, 23, 42, 0.84);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.seo-header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-link img {
  width: 46px;
  height: 46px;
  filter: drop-shadow(0 4px 12px rgba(59, 130, 246, 0.42));
}

.brand-copy {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.brand-name {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #60a5fa 0%, #a78bfa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.brand-tag {
  font-size: 0.82rem;
  color: var(--text-muted);
}

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

.seo-nav a {
  text-decoration: none;
  color: var(--text-soft);
  font-size: 0.96rem;
  padding: 0.7rem 1rem;
  border-radius: 999px;
  transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.seo-nav a:hover {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.06);
  transform: translateY(-1px);
}

.seo-nav .nav-cta {
  background: linear-gradient(135deg, var(--blue) 0%, var(--violet) 100%);
  color: #fff;
  box-shadow: 0 10px 24px rgba(59, 130, 246, 0.32);
}

.page-main {
  position: relative;
  z-index: 1;
}

.hero {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 4.5rem 1.5rem 2.2rem;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(300px, 0.92fr);
  gap: 2rem;
  align-items: center;
}

.hero-copy,
.hero-visual,
.stats-strip,
.toc-card,
.content-card,
.cta-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow);
}

.hero-copy {
  border-radius: var(--radius-xl);
  padding: 2.35rem;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.45rem 0.9rem;
  border-radius: 999px;
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(96, 165, 250, 0.28);
  color: #bfdbfe;
  font-weight: 600;
  font-size: 0.86rem;
  letter-spacing: 0.01em;
}

.eyebrow strong {
  color: #fff;
}

.page-title {
  margin: 1.15rem 0 0.95rem;
  font-size: clamp(2.3rem, 6vw, 4.2rem);
  line-height: 1.04;
  letter-spacing: -0.05em;
}

.page-title .gradient-text {
  background: linear-gradient(135deg, #60a5fa 0%, #c084fc 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-lead {
  color: var(--text-soft);
  font-size: 1.06rem;
  line-height: 1.78;
  max-width: 64ch;
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin: 1.4rem 0 1.55rem;
}

.meta-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.65rem 0.9rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: var(--text-soft);
  font-size: 0.92rem;
}

.hero-actions {
  display: flex;
  gap: 0.9rem;
  flex-wrap: wrap;
  margin-top: 1.65rem;
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  min-height: 52px;
  padding: 0.9rem 1.4rem;
  border-radius: 14px;
  text-decoration: none;
  font-weight: 700;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--blue-deep) 0%, var(--violet-deep) 100%);
  box-shadow: 0 14px 28px rgba(59, 130, 246, 0.3);
}

.btn-secondary {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
}

.btn-primary:hover,
.btn-secondary:hover {
  transform: translateY(-2px);
}

.hero-visual {
  border-radius: var(--radius-xl);
  padding: 1.2rem;
}

.hero-visual img {
  width: 100%;
  height: min(540px, 62vw);
  object-fit: cover;
  border-radius: 22px;
}

.visual-caption {
  margin-top: 1rem;
  padding: 1rem 1.05rem;
  border-radius: 18px;
  background: rgba(2, 6, 23, 0.44);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.visual-caption strong {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 1rem;
}

.visual-caption p {
  margin: 0;
  color: var(--text-soft);
  line-height: 1.6;
}

.stats-strip {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.1rem;
  border-radius: 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.stat-card {
  padding: 1rem 1.05rem;
  border-radius: 18px;
  background: rgba(2, 6, 23, 0.28);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.stat-label {
  display: block;
  color: var(--text-muted);
  font-size: 0.83rem;
  margin-bottom: 0.45rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.stat-value {
  font-size: 1.45rem;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.page-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.8rem 1.5rem 4.2rem;
  display: grid;
  grid-template-columns: 290px minmax(0, 1fr);
  gap: 1.5rem;
  align-items: start;
}

.sidebar {
  position: sticky;
  top: 96px;
}

.toc-card {
  border-radius: 22px;
  padding: 1.25rem;
}

.toc-card h2 {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
}

.toc-card p {
  margin: 0 0 1rem;
  color: var(--text-muted);
  line-height: 1.55;
  font-size: 0.94rem;
}

.toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.55rem;
}

.toc-list a {
  display: block;
  text-decoration: none;
  color: var(--text-soft);
  padding: 0.72rem 0.85rem;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.toc-list a:hover {
  color: var(--text-main);
  background: rgba(59, 130, 246, 0.1);
}

.content-stack {
  display: grid;
  gap: 1.5rem;
}

.content-card {
  border-radius: var(--radius-lg);
  padding: 1.8rem;
}

.content-card h2 {
  margin: 0 0 0.85rem;
  font-size: clamp(1.45rem, 3vw, 2rem);
  letter-spacing: -0.04em;
}

.content-card h3 {
  margin: 1.3rem 0 0.65rem;
  font-size: 1.12rem;
  letter-spacing: -0.02em;
}

.content-card p {
  margin: 0 0 1rem;
  color: var(--text-soft);
  line-height: 1.82;
  font-size: 1rem;
}

.content-card ul,
.content-card ol {
  margin: 0;
  padding-left: 1.15rem;
  color: var(--text-soft);
  line-height: 1.75;
}

.content-card li + li {
  margin-top: 0.45rem;
}

.content-card strong {
  color: #fff;
}

.split-grid,
.feature-grid,
.faq-grid,
.related-grid,
.two-col-grid {
  display: grid;
  gap: 1rem;
}

.split-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.feature-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 1rem;
}

.faq-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 0.6rem;
}

.related-grid,
.two-col-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.feature-card,
.faq-item,
.related-card,
.note-card,
.question-card,
.table-wrap,
.checklist-card {
  border-radius: 18px;
  background: rgba(2, 6, 23, 0.32);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.feature-card,
.faq-item,
.related-card,
.note-card,
.question-card,
.checklist-card {
  padding: 1.1rem;
}

.feature-card h3,
.faq-item h3,
.related-card h3,
.note-card h3,
.question-card h3,
.checklist-card h3 {
  margin-top: 0;
}

.note-card {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.14), rgba(139, 92, 246, 0.12));
}

.checklist {
  list-style: none;
  padding: 0;
  margin: 0;
}

.checklist li {
  position: relative;
  padding-left: 1.65rem;
}

.checklist li::before {
  content: '✓';
  position: absolute;
  left: 0;
  top: 0;
  color: var(--green);
  font-weight: 800;
}

.question-grid {
  display: grid;
  gap: 0.9rem;
  margin-top: 1rem;
}

.question-card p:last-child,
.faq-item p:last-child,
.related-card p:last-child,
.note-card p:last-child,
.feature-card p:last-child {
  margin-bottom: 0;
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 620px;
}

.comparison-table th,
.comparison-table td {
  text-align: left;
  padding: 0.95rem 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  color: var(--text-soft);
  vertical-align: top;
}

.comparison-table th {
  color: #fff;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
}

.comparison-table td strong {
  color: #fff;
}

.table-wrap {
  overflow-x: auto;
  padding: 0.3rem;
}

.quote-block {
  margin-top: 1rem;
  padding: 1.15rem 1.2rem;
  border-left: 4px solid var(--blue);
  border-radius: 16px;
  background: rgba(59, 130, 246, 0.09);
  color: var(--text-soft);
}

.quote-block strong {
  display: block;
  margin-top: 0.55rem;
}

.cta-panel {
  max-width: var(--max-width);
  margin: 0 auto 4rem;
  padding: 2rem 1.5rem;
  border-radius: 28px;
}

.cta-panel-inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 1.4rem;
  align-items: center;
}

.cta-panel h2 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.7rem, 4vw, 2.5rem);
  letter-spacing: -0.05em;
}

.cta-panel p {
  margin: 0;
  color: var(--text-soft);
  line-height: 1.75;
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  justify-content: flex-start;
}

.related-card {
  text-decoration: none;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.related-card:hover {
  transform: translateY(-2px);
  border-color: rgba(96, 165, 250, 0.4);
}

.related-card span {
  display: inline-flex;
  margin-top: 0.6rem;
  color: #bfdbfe;
  font-weight: 600;
}

.page-footer {
  border-top: 1px solid var(--border);
  background: rgba(2, 6, 23, 0.52);
}

.page-footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.6rem 1.5rem 2.2rem;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  flex-wrap: wrap;
}

.page-footer p {
  margin: 0;
  color: var(--text-muted);
  line-height: 1.6;
}

.page-footer-links {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.page-footer-links a {
  text-decoration: none;
  color: var(--text-soft);
}

.page-footer-links a:hover {
  color: #fff;
}

@media (max-width: 1040px) {
  .hero,
  .page-grid,
  .cta-panel-inner,
  .feature-grid,
  .faq-grid,
  .related-grid,
  .split-grid,
  .two-col-grid,
  .stats-strip {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
  }

  .hero-visual img {
    height: auto;
  }
}

@media (max-width: 720px) {
  .seo-header-inner,
  .hero,
  .page-grid,
  .cta-panel,
  .page-footer-inner {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .hero-copy,
  .hero-visual,
  .content-card,
  .toc-card,
  .cta-panel {
    padding: 1.2rem;
  }

  .seo-nav {
    width: 100%;
    justify-content: flex-start;
  }

  .page-title {
    font-size: 2.2rem;
  }

  .hero-actions,
  .cta-actions {
    flex-direction: column;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
  }
}