:root {
    --navy: #0A192F;
    --navy-700: #122444;
    --navy-soft: rgba(10, 25, 47, 0.72);
    --navy-muted: rgba(10, 25, 47, 0.56);
    --navy-faint: rgba(10, 25, 47, 0.10);
    --navy-line: rgba(10, 25, 47, 0.08);
    --white: #FFFFFF;
    --ash: #E6E6E6;
    --ash-soft: #F4F4F4;
    --ash-cool: #F8F9FB;
    --accent: #0A192F;
    --accent-bright: #1E3A8A;
    --success: #0E7C5A;
    --radius-sm: 6px;
    --radius: 10px;
    --radius-lg: 14px;
    --container: 1200px;
    --gutter: clamp(20px, 4vw, 48px);
    --section: clamp(80px, 10vw, 140px);
  }

  * { box-sizing: border-box; margin: 0; padding: 0; }

  html { scroll-behavior: smooth; }

  body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    color: var(--navy);
    background: var(--white);
    line-height: 1.55;
    font-weight: 400;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
  }

  ::selection { background: var(--navy); color: var(--white); }

  a { color: inherit; text-decoration: none; }
  button { font-family: inherit; cursor: pointer; border: none; background: none; }

  .container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 var(--gutter);
  }

  /* ========================= NAV ========================= */
  .nav {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom: 1px solid var(--navy-line);
  }
  .nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
  }
  .logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 18px;
    letter-spacing: -0.02em;
  }
  .logo-mark {
    width: 28px;
    height: 28px;
    border-radius: 6px;
    background: var(--navy);
    display: grid;
    place-items: center;
    color: var(--white);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: -0.04em;
  }
  .nav-links {
    display: flex;
    gap: 36px;
    align-items: center;
    list-style: none;
    font-size: 14px;
    font-weight: 500;
    color: var(--navy-soft);
  }
  .nav-links a { transition: color .2s ease; }
  .nav-links a:hover { color: var(--navy); }

  .btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 22px;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 600;
    letter-spacing: -0.005em;
    transition: transform .15s ease, background .2s ease, color .2s ease, border-color .2s ease, box-shadow .2s ease;
    white-space: nowrap;
  }
  .btn-primary {
    background: var(--navy);
    color: var(--white);
    box-shadow: 0 1px 0 rgba(255,255,255,0.06) inset, 0 8px 24px -10px rgba(10,25,47,0.45);
  }
  .btn-primary:hover { background: var(--navy-700); transform: translateY(-1px); }
  .btn-ghost {
    background: transparent;
    color: var(--navy);
    border: 1px solid var(--navy-line);
  }
  .btn-ghost:hover { border-color: var(--navy); }
  .btn .arrow { transition: transform .2s ease; }
  .btn:hover .arrow { transform: translateX(3px); }

  @media (max-width: 820px) {
    .nav-links { display: none; }
  }

  /* ========================= HERO ========================= */
  .hero {
    position: relative;
    padding: clamp(80px, 12vw, 140px) 0 clamp(60px, 8vw, 100px);
    overflow: hidden;
  }
  .hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
      linear-gradient(var(--navy-line) 1px, transparent 1px),
      linear-gradient(90deg, var(--navy-line) 1px, transparent 1px);
    background-size: 64px 64px;
    background-position: -1px -1px;
    mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 75%);
    -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 75%);
    pointer-events: none;
  }
  .hero-inner { position: relative; }
  .eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--navy-soft);
    padding: 8px 14px;
    border: 1px solid var(--navy-line);
    border-radius: 999px;
    background: var(--white);
  }
  .eyebrow .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--success);
    box-shadow: 0 0 0 3px rgba(14,124,90,0.15);
  }
  .hero h1 {
    margin-top: 28px;
    font-size: clamp(40px, 6.4vw, 84px);
    font-weight: 700;
    line-height: 1.02;
    letter-spacing: -0.035em;
    max-width: 16ch;
  }
  .hero h1 em {
    font-style: normal;
    color: var(--navy-muted);
    font-weight: 400;
  }
  .hero-sub {
    margin-top: 28px;
    max-width: 58ch;
    font-size: clamp(17px, 1.4vw, 19px);
    line-height: 1.55;
    color: var(--navy-soft);
    font-weight: 400;
  }
  .hero-cta {
    margin-top: 40px;
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
  }
  .hero-meta {
    margin-top: 60px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1px;
    background: var(--navy-line);
    border: 1px solid var(--navy-line);
    border-radius: var(--radius-lg);
    overflow: hidden;
  }
  .hero-meta div {
    background: var(--white);
    padding: 24px 22px;
  }
  .hero-meta .k {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.10em;
    text-transform: uppercase;
    color: var(--navy-muted);
  }
  .hero-meta .v {
    margin-top: 6px;
    font-size: 15px;
    font-weight: 600;
    letter-spacing: -0.01em;
  }
  @media (max-width: 740px) {
    .hero-meta { grid-template-columns: repeat(2, 1fr); }
  }

  /* ========================= SECTION HEADERS ========================= */
  section { padding: var(--section) 0; }
  .section-head {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: clamp(24px, 4vw, 64px);
    margin-bottom: clamp(48px, 6vw, 80px);
    align-items: start;
  }
  .section-num {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.08em;
    color: var(--navy-muted);
    padding-top: 8px;
    border-top: 1px solid var(--navy);
  }
  .section-title {
    font-size: clamp(28px, 3.8vw, 48px);
    font-weight: 700;
    line-height: 1.08;
    letter-spacing: -0.025em;
    max-width: 22ch;
  }
  .section-lede {
    margin-top: 22px;
    font-size: clamp(16px, 1.2vw, 18px);
    color: var(--navy-soft);
    max-width: 60ch;
    line-height: 1.6;
  }
  @media (max-width: 720px) {
    .section-head { grid-template-columns: 1fr; gap: 16px; }
    .section-num { padding-top: 12px; }
  }

  /* ========================= PROBLEM ========================= */
  .problem { background: var(--ash-cool); border-top: 1px solid var(--navy-line); border-bottom: 1px solid var(--navy-line); }
  .risks-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1px;
    background: var(--navy-line);
    border: 1px solid var(--navy-line);
    border-radius: var(--radius-lg);
    overflow: hidden;
  }
  .risk {
    background: var(--white);
    padding: clamp(28px, 3vw, 40px);
    transition: background .25s ease;
  }
  .risk:hover { background: var(--ash-soft); }
  .risk-tag {
    display: inline-block;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.10em;
    text-transform: uppercase;
    color: #B91C1C;
    background: #FEF2F2;
    padding: 5px 10px;
    border-radius: 4px;
    margin-bottom: 18px;
  }
  .risk h3 {
    font-size: 19px;
    font-weight: 600;
    letter-spacing: -0.015em;
    margin-bottom: 10px;
    line-height: 1.3;
  }
  .risk p {
    font-size: 15px;
    line-height: 1.6;
    color: var(--navy-soft);
  }
  .risk .ref {
    margin-top: 14px;
    font-size: 12px;
    font-weight: 500;
    color: var(--navy-muted);
    font-feature-settings: "tnum";
  }
  @media (max-width: 720px) {
    .risks-grid { grid-template-columns: 1fr; }
  }

  /* ========================= PARADIGM SHIFT ========================= */
  .shift-box {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: clamp(20px, 3vw, 48px);
    align-items: stretch;
    padding: clamp(32px, 4vw, 56px);
    background: var(--white);
    border: 1px solid var(--navy-line);
    border-radius: var(--radius-lg);
    margin-bottom: 40px;
  }
  .shift-col h4 {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--navy-muted);
    margin-bottom: 18px;
  }
  .shift-col .quote {
    font-size: clamp(20px, 2.2vw, 26px);
    font-weight: 500;
    letter-spacing: -0.02em;
    line-height: 1.35;
    color: var(--navy-muted);
    text-decoration: line-through;
    text-decoration-color: rgba(185, 28, 28, 0.4);
    text-decoration-thickness: 1.5px;
  }
  .shift-col.to .quote {
    color: var(--navy);
    text-decoration: none;
    font-weight: 500;
  }
  .shift-col.to .quote strong {
    font-weight: 600;
    background: linear-gradient(180deg, transparent 60%, rgba(10,25,47,0.10) 60%);
  }
  .shift-arrow {
    align-self: center;
    color: var(--navy-muted);
    flex-shrink: 0;
  }
  @media (max-width: 760px) {
    .shift-box { grid-template-columns: 1fr; }
    .shift-arrow { transform: rotate(90deg); justify-self: start; }
  }

  /* ========================= PILLARS ========================= */
  .pillars-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1px;
    background: var(--navy-line);
    border: 1px solid var(--navy-line);
    border-radius: var(--radius-lg);
    overflow: hidden;
  }
  .pillar {
    background: var(--white);
    padding: clamp(28px, 2.5vw, 36px);
    display: flex;
    flex-direction: column;
    gap: 16px;
    min-height: 280px;
    transition: background .25s ease;
  }
  .pillar:hover { background: var(--ash-soft); }
  .pillar-icon {
    width: 44px;
    height: 44px;
    border-radius: 8px;
    background: var(--navy);
    color: var(--white);
    display: grid;
    place-items: center;
  }
  .pillar h3 {
    font-size: 17px;
    font-weight: 600;
    letter-spacing: -0.01em;
    line-height: 1.3;
  }
  .pillar p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--navy-soft);
    margin-top: auto;
  }
  @media (max-width: 980px) {
    .pillars-grid { grid-template-columns: repeat(2, 1fr); }
  }
  @media (max-width: 540px) {
    .pillars-grid { grid-template-columns: 1fr; }
  }

  /* ========================= FLOW ========================= */
  .flow { background: var(--navy); color: var(--white); }
  .flow .section-num { color: rgba(255,255,255,0.5); border-top-color: rgba(255,255,255,0.6); }
  .flow .section-title { color: var(--white); }
  .flow .section-lede { color: rgba(255,255,255,0.7); }

  .phases {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1px;
    background: rgba(255,255,255,0.08);
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid rgba(255,255,255,0.08);
  }
  .phase {
    background: var(--navy);
    padding: clamp(28px, 3vw, 40px) clamp(24px, 3vw, 36px);
    display: grid;
    grid-template-columns: 80px 1fr 2fr;
    gap: clamp(20px, 3vw, 48px);
    align-items: start;
    transition: background .25s ease;
  }
  .phase:hover { background: var(--navy-700); }
  .phase-num {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.08em;
    color: rgba(255,255,255,0.5);
    padding-top: 4px;
    font-feature-settings: "tnum";
  }
  .phase-title {
    font-size: clamp(18px, 1.5vw, 22px);
    font-weight: 600;
    letter-spacing: -0.015em;
    line-height: 1.3;
  }
  .phase-desc {
    font-size: 15px;
    color: rgba(255,255,255,0.72);
    line-height: 1.6;
  }
  .phase-desc ul {
    list-style: none;
    margin-top: 10px;
  }
  .phase-desc li {
    position: relative;
    padding-left: 22px;
    margin-bottom: 6px;
    font-size: 14px;
  }
  .phase-desc li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 9px;
    width: 12px;
    height: 1px;
    background: rgba(255,255,255,0.4);
  }
  @media (max-width: 760px) {
    .phase { grid-template-columns: 1fr; gap: 12px; }
    .phase-num { padding-top: 0; }
  }

  /* ========================= ARCO ========================= */
  .arco-grid {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: clamp(24px, 4vw, 64px);
    align-items: center;
  }
  .arco-text h3 {
    font-size: clamp(22px, 2.4vw, 30px);
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.2;
    margin-bottom: 20px;
  }
  .arco-text p {
    font-size: 16px;
    color: var(--navy-soft);
    line-height: 1.65;
    margin-bottom: 18px;
  }
  .arco-list {
    list-style: none;
    margin-top: 28px;
  }
  .arco-list li {
    display: flex;
    gap: 14px;
    padding: 14px 0;
    border-top: 1px solid var(--navy-line);
    align-items: flex-start;
  }
  .arco-list li:last-child { border-bottom: 1px solid var(--navy-line); }
  .arco-letter {
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    border-radius: 6px;
    background: var(--navy);
    color: var(--white);
    font-weight: 700;
    font-size: 14px;
    display: grid;
    place-items: center;
  }
  .arco-list strong {
    display: block;
    font-weight: 600;
    margin-bottom: 2px;
    font-size: 15px;
  }
  .arco-list span {
    font-size: 14px;
    color: var(--navy-soft);
  }

  .arco-card {
    background: var(--ash-cool);
    border: 1px solid var(--navy-line);
    border-radius: var(--radius-lg);
    padding: clamp(28px, 3vw, 36px);
    position: relative;
    overflow: hidden;
  }
  .arco-card-head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 18px;
    border-bottom: 1px solid var(--navy-line);
    margin-bottom: 20px;
  }
  .arco-card-head .label {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.10em;
    text-transform: uppercase;
    color: var(--navy-muted);
  }
  .arco-card-head .status {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    font-weight: 600;
    color: #B45309;
    background: #FEF3C7;
    padding: 4px 10px;
    border-radius: 999px;
  }
  .arco-row {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    font-size: 14px;
  }
  .arco-row .l { color: var(--navy-muted); }
  .arco-row .r { font-weight: 500; font-feature-settings: "tnum"; }
  .arco-action {
    margin-top: 24px;
    width: 100%;
    background: var(--navy);
    color: var(--white);
    padding: 12px 20px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    transition: background .2s ease;
  }
  .arco-action:hover { background: var(--navy-700); }
  @media (max-width: 880px) {
    .arco-grid { grid-template-columns: 1fr; }
  }

  /* ========================= ARCHITECTURE ========================= */
  .arch { background: var(--ash-cool); border-top: 1px solid var(--navy-line); border-bottom: 1px solid var(--navy-line); }
  .stack-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }
  .stack-card {
    background: var(--white);
    border: 1px solid var(--navy-line);
    border-radius: var(--radius);
    padding: 24px;
    transition: border-color .25s ease, transform .25s ease;
  }
  .stack-card:hover { border-color: var(--navy); transform: translateY(-2px); }
  .stack-label {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.10em;
    text-transform: uppercase;
    color: var(--navy-muted);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
  }
  .stack-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--navy); }
  .stack-card h4 {
    font-size: 17px;
    font-weight: 600;
    letter-spacing: -0.01em;
    margin-bottom: 8px;
  }
  .stack-card p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--navy-soft);
  }
  .stack-card code {
    font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;
    font-size: 12px;
    background: var(--ash-soft);
    padding: 2px 7px;
    border-radius: 4px;
    color: var(--navy);
    border: 1px solid var(--navy-line);
  }
  @media (max-width: 880px) { .stack-grid { grid-template-columns: repeat(2, 1fr); } }
  @media (max-width: 540px) { .stack-grid { grid-template-columns: 1fr; } }

  /* ========================= RECIPROCITY ========================= */
  .recip-box {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1px;
    background: var(--navy-line);
    border: 1px solid var(--navy-line);
    border-radius: var(--radius-lg);
    overflow: hidden;
  }
  .recip-half {
    background: var(--white);
    padding: clamp(36px, 4vw, 56px);
  }
  .recip-half h3 {
    font-size: clamp(20px, 2vw, 26px);
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.2;
    margin-bottom: 14px;
  }
  .recip-half p {
    font-size: 15px;
    line-height: 1.65;
    color: var(--navy-soft);
    margin-bottom: 24px;
  }
  .recip-list {
    list-style: none;
  }
  .recip-list li {
    font-size: 14px;
    padding: 10px 0;
    border-top: 1px solid var(--navy-line);
    display: flex;
    align-items: flex-start;
    gap: 10px;
    color: var(--navy-soft);
  }
  .recip-list li:last-child { border-bottom: 1px solid var(--navy-line); }
  .recip-list svg { flex-shrink: 0; margin-top: 4px; }
  @media (max-width: 720px) { .recip-box { grid-template-columns: 1fr; } }

  /* ========================= CTA ========================= */
  .cta {
    text-align: center;
    background: var(--navy);
    color: var(--white);
    border-radius: var(--radius-lg);
    padding: clamp(56px, 8vw, 96px) clamp(24px, 4vw, 48px);
    margin-bottom: var(--section);
    position: relative;
    overflow: hidden;
  }
  .cta::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
      linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px),
      linear-gradient(90deg, rgba(255,255,255,0.04) 1px, transparent 1px);
    background-size: 64px 64px;
    mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, #000 30%, transparent 80%);
    -webkit-mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, #000 30%, transparent 80%);
  }
  .cta-inner { position: relative; }
  .cta h2 {
    font-size: clamp(30px, 4vw, 52px);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.05;
    max-width: 18ch;
    margin: 0 auto;
  }
  .cta p {
    margin: 24px auto 36px;
    font-size: clamp(15px, 1.2vw, 17px);
    color: rgba(255,255,255,0.72);
    max-width: 56ch;
    line-height: 1.6;
  }
  .cta-buttons {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
  }
  .cta .btn-primary { background: var(--white); color: var(--navy); }
  .cta .btn-primary:hover { background: var(--ash); }
  .cta .btn-ghost { color: var(--white); border-color: rgba(255,255,255,0.25); }
  .cta .btn-ghost:hover { border-color: var(--white); }

  /* ========================= FOOTER ========================= */
  footer {
    border-top: 1px solid var(--navy-line);
    padding: 56px 0 40px;
    background: var(--white);
  }
  .footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 56px;
  }
  .footer-brand p {
    font-size: 14px;
    color: var(--navy-soft);
    line-height: 1.6;
    margin-top: 16px;
    max-width: 36ch;
  }
  .footer-col h5 {
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.10em;
    text-transform: uppercase;
    color: var(--navy-muted);
    margin-bottom: 18px;
  }
  .footer-col ul { list-style: none; }
  .footer-col li { margin-bottom: 10px; font-size: 14px; }
  .footer-col a { color: var(--navy-soft); transition: color .2s ease; }
  .footer-col a:hover { color: var(--navy); }
  .footer-bottom {
    padding-top: 32px;
    border-top: 1px solid var(--navy-line);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
    color: var(--navy-muted);
    flex-wrap: wrap;
    gap: 16px;
  }
  .footer-legal { display: flex; gap: 24px; flex-wrap: wrap; }
  .footer-legal a:hover { color: var(--navy); }
  @media (max-width: 880px) {
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 36px; }
  }
  @media (max-width: 540px) {
    .footer-grid { grid-template-columns: 1fr; }
  }

  /* ========================= REVEAL ANIMATION ========================= */
  .reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity .6s ease, transform .6s ease;
  }
  .reveal.in {
    opacity: 1;
    transform: translateY(0);
  }
  @media (prefers-reduced-motion: reduce) {
    .reveal { opacity: 1; transform: none; transition: none; }
    html { scroll-behavior: auto; }
  }

  /* Focus visible */
  a:focus-visible, button:focus-visible {
    outline: 2px solid var(--navy);
    outline-offset: 3px;
    border-radius: 4px;
  }