/* MH-1 AEO/SEO LP — v4 design system (revised per feedback)
 * Geist throughout (no serif). Clerk-style alternating light / light-alt / dark sections.
 * Dark accents: anchor-card visuals embedded on light bg, plus full-width dark sections.
 */

@import url('https://fonts.googleapis.com/css2?family=Geist:wght@400;500;600;700;800&family=Geist+Mono:wght@400;500&display=swap');

:root {
  /* Brand */
  --color-accent: #6BFFDC;
  --color-accent-hover: #4EE5C2;
  --color-accent-deep: #0E6E5C;

  /* Light surfaces (page primary) */
  --color-white: #FFFFFF;
  --color-paper: #F8F8FA;
  --color-paper-2: #F2F2F5;
  --color-ash: #EEEEF0;
  --color-stone: #E4E4E8;
  --color-slate: #D9D9DE;
  --color-graphite: #9394A1;
  --color-tungsten: #6F7080;
  --color-iron: #5A5B6A;
  --color-charcoal-2: #2E2F38;
  --color-charcoal: #0F0F12;

  /* Dark surfaces (anchor cards + dark sections) */
  --color-bg-dark: #08090a;
  --color-bg-dark-alt: #0c0d0f;
  --color-bg-dark-card: #131418;
  --color-bg-dark-emph: #1c1d22;
  --color-fg-dark-muted: #c8cad0;
  --color-fg-dark-subtle: #8c8f95;
  --color-fg-dark-faint: #5e6068;
  --color-border-dark-subtle: #1d1e22;
  --color-border-dark-emph: #2a2b30;

  /* Status */
  --color-error: #b33d2e;

  /* Typography — Geist only */
  --font-sans: 'Geist', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'Geist Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

  /* Layout */
  --page-max: 1200px;
  --page-max-wide: 1280px;
  --container-padding: 24px;
  --section-pad-y: 96px;
  --section-pad-y-lg: 128px;

  /* Radii */
  --radius-button: 8px;
  --radius-card: 12px;
  --radius-card-lg: 16px;
  --radius-pill: 9999px;

  /* Shadows */
  --shadow-card-light: 0 0 0 1px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.04), 0 8px 24px -8px rgba(15,15,18,0.08);
  --shadow-card-light-hover: 0 0 0 1px rgba(0,0,0,0.06), 0 12px 28px -8px rgba(15,15,18,0.10);
  --shadow-hero-card: 0 0 0 1px rgba(0,0,0,0.05), 0 8px 24px -6px rgba(15,15,18,0.10), 0 40px 80px -16px rgba(15,15,18,0.18);
  --shadow-deliverable-dark: 0 0 0 1px rgba(255,255,255,0.04), 0 6px 18px -4px rgba(0,0,0,0.4), 0 32px 80px -24px rgba(0,0,0,0.55);

  /* Mono caption tracking */
  --mono-track: 0.18em;
  --mono-track-tight: 0.10em;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  font-feature-settings: "ss01", "ss03", "cv11";
  font-size: 15px;
  line-height: 1.55;
  color: var(--color-charcoal);
  background: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  letter-spacing: -0.005em;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: 0; background: none; color: inherit; }
input, textarea { font: inherit; color: inherit; }
::selection { background: rgba(107, 255, 220, 0.30); color: var(--color-charcoal); }

/* Layout primitives */
.container {
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}
.container--wide { max-width: var(--page-max-wide); }
.container--narrow { max-width: 820px; }

.section { padding: var(--section-pad-y) 0; }
.section--lg { padding: var(--section-pad-y-lg) 0; }
.section--white { background: var(--color-white); }
.section--paper { background: var(--color-paper); }
.section--dark {
  background: var(--color-bg-dark);
  color: var(--color-fg-dark-muted);
}
.section--dark .h1, .section--dark .h2, .section--dark .h3, .section--dark .h4,
.section--dark .t-display, .section--dark .t-h2, .section--dark .t-h3, .section--dark .t-h4 {
  color: #ffffff;
}

.section--hero-glow { position: relative; overflow: hidden; }
.section--hero-glow::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(60% 50% at 50% 0%, rgba(107, 255, 220, 0.06), transparent 60%),
    linear-gradient(180deg, var(--color-paper) 0%, var(--color-white) 70%);
  pointer-events: none;
  z-index: 0;
}
.section--dark.section--hero-glow::before {
  background: radial-gradient(60% 50% at 50% 0%, rgba(107, 255, 220, 0.06), transparent 60%);
}
.section--hero-glow > .container,
.section--hero-glow > .container--wide,
.section--hero-glow > .anchor-wrap,
.section--hero-glow > .impact-strip,
.section--hero-glow > .logo-cloud { position: relative; z-index: 1; }

/* Type — Geist-only display + headings */
.t-display {
  font-family: var(--font-sans);
  font-size: clamp(44px, 5.6vw, 76px);
  line-height: 1.02;
  letter-spacing: -0.038em;
  font-weight: 700;
  color: var(--color-charcoal);
}
.t-h2 {
  font-family: var(--font-sans);
  font-size: clamp(32px, 3.6vw, 44px);
  line-height: 1.06;
  letter-spacing: -0.030em;
  font-weight: 700;
  color: var(--color-charcoal);
}
.t-h3 {
  font-family: var(--font-sans);
  font-size: clamp(22px, 2.4vw, 28px);
  line-height: 1.18;
  letter-spacing: -0.020em;
  font-weight: 600;
  color: var(--color-charcoal);
}
.t-h4 {
  font-size: 17px;
  line-height: 1.30;
  letter-spacing: -0.012em;
  font-weight: 600;
  color: var(--color-charcoal);
}
.section--dark .t-display, .section--dark .t-h2, .section--dark .t-h3, .section--dark .t-h4 {
  color: #ffffff;
}

.body-xl { font-size: 19px; line-height: 1.55; font-weight: 400; }
.body-lg { font-size: 17px; line-height: 1.55; font-weight: 400; color: var(--color-iron); }
.section--dark .body-lg { color: var(--color-fg-dark-muted); }
.body { font-size: 15px; line-height: 1.55; font-weight: 400; color: var(--color-iron); }
.body-sm { font-size: 13.5px; line-height: 1.5; font-weight: 400; color: var(--color-iron); }
.body-xs { font-size: 12px; line-height: 1.5; font-weight: 400; }

.muted { color: var(--color-tungsten); }
.section--dark .muted { color: var(--color-fg-dark-subtle); }
.subtle { color: var(--color-graphite); }
.section--dark .subtle { color: var(--color-fg-dark-faint); }
.accent-text { color: var(--color-accent-deep); }
.section--dark .accent-text { color: var(--color-accent); }

/* Mono caption */
.mono-cap {
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: var(--mono-track);
  color: var(--color-tungsten);
  font-weight: 500;
}
.section--dark .mono-cap { color: var(--color-fg-dark-subtle); }

/* Eyebrow with status dot */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: var(--mono-track);
  color: var(--color-tungsten);
  font-weight: 500;
}
.section--dark .eyebrow { color: var(--color-fg-dark-subtle); }
.eyebrow::before {
  content: "";
  width: 6px; height: 6px; border-radius: 9999px;
  background: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(107, 255, 220, 0.18);
}

.section-num {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: var(--mono-track);
  color: var(--color-tungsten);
  font-weight: 500;
}
.section--dark .section-num { color: var(--color-fg-dark-subtle); }
.section-num strong { color: var(--color-charcoal); font-weight: 500; margin-right: 4px; }
.section--dark .section-num strong { color: #ffffff; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: var(--radius-button);
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 14px;
  letter-spacing: -0.005em;
  transition: all 0.18s ease;
  white-space: nowrap;
  height: 40px;
  padding: 0 18px;
}
.btn--lg { font-size: 15px; height: 46px; padding: 0 22px; }
.btn--primary {
  background: var(--color-charcoal);
  color: var(--color-white);
  box-shadow: 0 1px 2px rgba(0,0,0,0.06), 0 6px 18px -4px rgba(0,0,0,0.10);
}
.btn--primary:hover { background: #000; transform: translateY(-1px); }
.btn--primary-on-dark {
  background: var(--color-white);
  color: var(--color-charcoal);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.04), 0 6px 18px -4px rgba(0, 0, 0, 0.4);
}
.btn--primary-on-dark:hover { transform: translateY(-1px); }
.btn--accent {
  background: var(--color-accent);
  color: #062c22;
  box-shadow: 0 0 0 1px rgba(107, 255, 220, 0.20), 0 6px 18px -4px rgba(107, 255, 220, 0.28);
}
.btn--accent:hover { background: var(--color-accent-hover); transform: translateY(-1px); }
.btn--secondary {
  background: var(--color-white);
  color: var(--color-charcoal);
  border: 1px solid var(--color-slate);
}
.btn--secondary:hover { background: var(--color-paper); border-color: var(--color-graphite); }
.section--dark .btn--secondary {
  background: transparent;
  color: #ffffff;
  border: 1px solid var(--color-border-dark-emph);
}
.section--dark .btn--secondary:hover { background: var(--color-bg-dark-card); border-color: #353539; }
.btn--ghost {
  background: transparent;
  color: var(--color-iron);
  height: 36px;
  padding: 0 12px;
  font-size: 14px;
}
.btn--ghost:hover { color: var(--color-charcoal); background: var(--color-paper); }

/* Cards (light) */
.card-light {
  background: var(--color-white);
  border: 1px solid var(--color-stone);
  border-radius: var(--radius-card);
  transition: border-color 0.2s, box-shadow 0.2s;
}
.card-light:hover { border-color: var(--color-graphite); box-shadow: var(--shadow-card-light-hover); }

/* Cards (dark anchor — for embedding on light pages) */
.card-dark {
  background: var(--color-bg-dark-card);
  border: 1px solid var(--color-border-dark-emph);
  border-radius: var(--radius-card-lg);
  box-shadow: var(--shadow-deliverable-dark);
  color: var(--color-fg-dark-muted);
}
.card-dark .t-h3, .card-dark .t-h4 { color: #ffffff; }

/* Sticky nav (light) */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  padding: 14px 0;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-stone);
}
.nav__inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.nav__logo {
  font-family: var(--font-sans);
  font-weight: 700;
  letter-spacing: -0.4px;
  font-size: 17px;
  color: var(--color-charcoal);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.nav__logo .mark {
  width: 22px; height: 22px;
  background: var(--color-charcoal);
  border-radius: 5px;
  display: inline-flex; align-items: center; justify-content: center;
  color: var(--color-white);
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 700;
}
.nav__module {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-tungsten);
  letter-spacing: var(--mono-track-tight);
  text-transform: uppercase;
  padding-left: 12px;
  border-left: 1px solid var(--color-stone);
}
.nav__links { display: flex; align-items: center; gap: 4px; }
@media (max-width: 880px) {
  .nav__module { display: none; }
  .nav__links a:not(:last-child) { display: none; }
}

/* Hairline */
.rule { height: 1px; background: var(--color-stone); border: 0; }
.section--dark .rule { background: var(--color-border-dark-subtle); }

/* Footer (simple black) */
.footer {
  background: var(--color-bg-dark);
  color: var(--color-fg-dark-faint);
  border-top: 1px solid var(--color-border-dark-subtle);
  padding: 36px 0;
}
.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}
.footer__copy {
  color: var(--color-fg-dark-faint);
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: var(--mono-track-tight);
}
.footer__links { display: flex; gap: 20px; }
.footer__links a {
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: var(--mono-track-tight);
  color: var(--color-fg-dark-faint);
  transition: color 0.15s;
}
.footer__links a:hover { color: var(--color-white); }
.footer .nav__logo { color: var(--color-white); }
.footer .nav__logo .mark { background: var(--color-white); color: var(--color-charcoal); }

/* Section head pattern */
.section-head {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: end;
  margin-bottom: 56px;
}
.section-head__left { display: flex; flex-direction: column; gap: 18px; }
.section-head__right {
  padding-bottom: 8px;
  color: var(--color-iron);
  font-size: 17px;
  line-height: 1.55;
}
.section--dark .section-head__right { color: var(--color-fg-dark-muted); }
@media (max-width: 880px) {
  .section-head { grid-template-columns: 1fr; gap: 18px; margin-bottom: 40px; }
}

/* Utility */
.mt-8 { margin-top: 8px; } .mt-16 { margin-top: 16px; } .mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; } .mt-48 { margin-top: 48px; } .mt-64 { margin-top: 64px; }
.text-center { text-align: center; }
.flex { display: flex; }
.gap-8 { gap: 8px; } .gap-12 { gap: 12px; } .gap-16 { gap: 16px; } .gap-24 { gap: 24px; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.flex-wrap { flex-wrap: wrap; }
.col { display: flex; flex-direction: column; }
.max-720 { max-width: 720px; }
.max-640 { max-width: 640px; }

/* Responsive */
@media (max-width: 880px) {
  :root {
    --section-pad-y: 64px;
    --section-pad-y-lg: 80px;
  }
}