:root {
    --bg: #05070f;
    --bg2: #0a0f1e;
    --bg3: #10182b;
    --card: rgba(14, 22, 42, 0.72);
    --line: rgba(0, 229, 255, 0.14);
    --cyan: #00e5ff;
    --blue: #3b82f6;
    --violet: #8b5cf6;
    --pink: #ec4899;
    --lime: #22d3a6;
    --gold: #fbbf24;
    --text: #e8eefc;
    --muted: #93a4c3;
    --white: #ffffff;
    --shadow: 0 20px 60px rgba(0,0,0,.45);
    --shadow-strong: 0 34px 90px rgba(0,0,0,.55);
    --radius: 22px;
  }

  * { box-sizing: border-box; margin: 0; padding: 0; }
  html { scroll-behavior: smooth; }
  body {
    font-family: "Vazirmatn", system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    overflow-x: hidden;
    line-height: 1.9;
  }

  /* animated space background */
  .bg-canvas {
    position: fixed; inset: 0; z-index: -2;
    background:
      radial-gradient(1200px 700px at 80% -10%, rgba(59,130,246,.22), transparent 60%),
      radial-gradient(900px 600px at -10% 20%, rgba(139,92,246,.18), transparent 55%),
      radial-gradient(800px 500px at 50% 110%, rgba(0,229,255,.12), transparent 50%),
      linear-gradient(180deg, #05070f, #070b16 40%, #05070f);
  }
  .grid-overlay {
    position: fixed; inset: 0; z-index: -1; pointer-events: none;
    background-image:
      linear-gradient(rgba(0,229,255,.04) 1px, transparent 1px),
      linear-gradient(90deg, rgba(0,229,255,.04) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(circle at center, black 20%, transparent 75%);
    animation: gridPulse 8s ease-in-out infinite;
  }
  @keyframes gridPulse {
    0%,100% { opacity: .45; transform: scale(1); }
    50% { opacity: .8; transform: scale(1.02); }
  }

  #particles { position: fixed; inset: 0; z-index: -1; pointer-events: none; }

  /* top nav */
  .topbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    display: flex; align-items: center; justify-content: space-between;
    padding: 14px 28px;
    backdrop-filter: blur(18px);
    background: rgba(5,7,15,.55);
    border-bottom: 1px solid var(--line);
    transition: .35s ease;
  }
  .topbar.scrolled { background: rgba(5,7,15,.85); box-shadow: 0 10px 40px rgba(0,0,0,.35); }
  .brand {
    display: flex; align-items: center; gap: 12px;
  }
  .logo {
    width: 42px; height: 42px; border-radius: 12px;
    background: linear-gradient(135deg, var(--cyan), var(--violet));
    display: grid; place-items: center;
    font-family: Orbitron, sans-serif; font-weight: 900; font-size: 13px; color: #041018;
    box-shadow: 0 0 24px rgba(0,229,255,.45);
    animation: logoGlow 3s ease-in-out infinite;
  }
  @keyframes logoGlow {
    0%,100% { box-shadow: 0 0 18px rgba(0,229,255,.35); }
    50% { box-shadow: 0 0 34px rgba(139,92,246,.55); }
  }
  .brand-text strong {
    display: block; font-size: 14px; letter-spacing: .5px;
  }
  .brand-text span {
    font-size: 11px; color: var(--muted); font-family: "Space Grotesk", sans-serif;
  }
  .nav-links { display: flex; gap: 8px; flex-wrap: wrap; }
  .nav-links a {
    text-decoration: none; color: var(--muted);
    font-size: 13px; padding: 8px 14px; border-radius: 999px;
    border: 1px solid transparent; transition: .25s ease;
  }
  .nav-links a:hover, .nav-links a.active {
    color: var(--white);
    border-color: rgba(0,229,255,.35);
    background: rgba(0,229,255,.08);
    box-shadow: 0 0 20px rgba(0,229,255,.12);
  }
  .doc-badge {
    font-family: "Space Grotesk", sans-serif;
    font-size: 11px; color: var(--cyan);
    border: 1px solid rgba(0,229,255,.3);
    padding: 7px 12px; border-radius: 999px;
    background: rgba(0,229,255,.07);
  }

  /* progress */
  .progress {
    position: fixed; top: 0; left: 0; height: 3px; width: 0%;
    background: linear-gradient(90deg, var(--cyan), var(--violet), var(--pink));
    z-index: 200; box-shadow: 0 0 12px var(--cyan);
  }

  /* hero */
  .hero {
    min-height: 100vh; padding: 140px 24px 80px;
    display: grid; place-items: center; text-align: center;
    position: relative; overflow: hidden;
  }
  .hero .wrap {
    position: relative;
    z-index: 1;
    opacity: var(--hero-fade, 1);
    transform: translate3d(0, var(--hero-shift, 0), 0);
    transition: opacity .2s linear;
  }
  .hero::before {
    content: "";
    position: absolute;
    inset: 7% 14% auto;
    height: 420px;
    border-radius: 40px;
    background:
      linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.015)),
      linear-gradient(135deg, rgba(0,229,255,.12), rgba(139,92,246,.09), rgba(236,72,153,.06));
    border: 1px solid rgba(255,255,255,.06);
    box-shadow: inset 0 1px 0 rgba(255,255,255,.08), 0 20px 100px rgba(0,229,255,.08);
    opacity: .9;
    pointer-events: none;
    transform: perspective(1200px) rotateX(9deg);
    mask-image: linear-gradient(180deg, rgba(0,0,0,.95), transparent 88%);
  }
  .hero-orb {
    position: absolute; border-radius: 50%; filter: blur(60px); opacity: .45;
    animation: float 10s ease-in-out infinite;
  }
  .orb1 { width: 320px; height: 320px; background: #00e5ff; top: 15%; right: 10%; }
  .orb2 { width: 280px; height: 280px; background: #8b5cf6; bottom: 10%; left: 8%; animation-delay: -3s; }
  .orb3 { width: 180px; height: 180px; background: #ec4899; top: 45%; left: 40%; animation-delay: -6s; }
  @keyframes float {
    0%,100% { transform: translateY(0) scale(1); }
    50% { transform: translateY(-30px) scale(1.08); }
  }

  .kicker {
    display: inline-flex; align-items: center; gap: 10px;
    padding: 8px 16px; border-radius: 999px;
    border: 1px solid rgba(0,229,255,.3);
    background: rgba(0,229,255,.08);
    color: var(--cyan); font-size: 13px; margin-bottom: 22px;
    animation: fadeUp .8s ease both;
  }
  .kicker i {
    width: 8px; height: 8px; border-radius: 50%; background: var(--cyan);
    box-shadow: 0 0 12px var(--cyan); animation: blink 1.4s infinite;
  }
  @keyframes blink { 0%,100%{opacity:1} 50%{opacity:.3} }

  .hero h1 {
    font-size: clamp(2rem, 5vw, 4.2rem);
    font-weight: 900; line-height: 1.25;
    background: linear-gradient(135deg, #fff 20%, #00e5ff 50%, #a78bfa 80%);
    -webkit-background-clip: text; background-clip: text; color: transparent;
    margin-bottom: 14px;
    animation: fadeUp .9s .1s ease both;
  }
  .hero .en-title {
    font-family: Orbitron, sans-serif;
    font-size: clamp(1rem, 2.2vw, 1.5rem);
    letter-spacing: 3px; color: var(--muted);
    margin-bottom: 22px;
    animation: fadeUp .9s .2s ease both;
  }
  .hero p.lead {
    max-width: 820px; margin: 0 auto 34px;
    color: var(--muted); font-size: 1.05rem;
    animation: fadeUp .9s .3s ease both;
  }
  .meta-row {
    display: flex; flex-wrap: wrap; gap: 12px; justify-content: center;
    margin-bottom: 40px;
    animation: fadeUp .9s .4s ease both;
  }
  .meta-chip {
    padding: 10px 16px; border-radius: 14px;
    background: linear-gradient(180deg, rgba(255,255,255,.045), rgba(255,255,255,.02));
    border: 1px solid rgba(255,255,255,.08);
    font-size: 13px;
    box-shadow: inset 0 1px 0 rgba(255,255,255,.04);
  }
  .meta-chip b { color: var(--cyan); display: block; font-size: 11px; margin-bottom: 2px; }
  .logic-flow {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 12px;
    margin: 0 auto 28px;
    max-width: 1120px;
  }
  .logic-step {
    position: relative;
    padding: 16px 14px;
    border-radius: 20px;
    background: linear-gradient(180deg, rgba(255,255,255,.045), rgba(255,255,255,.02));
    border: 1px solid rgba(255,255,255,.08);
    text-align: right;
    overflow: hidden;
    box-shadow: inset 0 1px 0 rgba(255,255,255,.05);
  }
  .logic-step::before {
    content: "";
    position: absolute;
    inset: auto -20% -50% auto;
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0,229,255,.18), transparent 68%);
    pointer-events: none;
  }
  .logic-step span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 10px;
    margin-bottom: 10px;
    font-family: Orbitron, sans-serif;
    font-size: .72rem;
    color: #041018;
    background: linear-gradient(135deg, var(--cyan), #7dd3fc);
    box-shadow: 0 8px 20px rgba(0,229,255,.22);
  }
  .logic-step strong {
    display: block;
    font-size: .92rem;
    margin-bottom: 4px;
    color: var(--white);
  }
  .logic-step small {
    display: block;
    color: rgba(232,238,252,.64);
    font-size: .73rem;
    line-height: 1.7;
  }
  .logic-step.is-active {
    border-color: rgba(0,229,255,.35);
    box-shadow: 0 18px 44px rgba(0,229,255,.14), inset 0 1px 0 rgba(255,255,255,.05);
    transform: translateY(-4px);
  }
  .claim-grid {
    display: grid;
    grid-template-columns: 1.15fr .9fr .9fr;
    gap: 18px;
    margin: 0 auto 28px;
    align-items: stretch;
  }
  .claim-card {
    position: relative;
    padding: 24px;
    border-radius: 26px;
    text-align: right;
    background:
      linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.02)),
      rgba(7,11,22,.74);
    border: 1px solid rgba(255,255,255,.08);
    box-shadow: var(--shadow);
    overflow: hidden;
  }
  .claim-card::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(0,229,255,.06), transparent 45%, rgba(139,92,246,.06));
    pointer-events: none;
  }
  .claim-card > * { position: relative; z-index: 1; }
  .claim-main {
    border-color: rgba(0,229,255,.2);
    box-shadow: 0 26px 70px rgba(0,229,255,.12), var(--shadow);
  }
  .claim-main h3,
  .outcome-card h4 {
    font-size: 1.24rem;
    line-height: 1.75;
    margin-bottom: 12px;
  }
  .claim-main p,
  .outcome-card p,
  .proof-item span {
    color: rgba(232,238,252,.72);
    line-height: 1.95;
    font-size: .92rem;
  }
  .proof-list {
    display: grid;
    gap: 12px;
  }
  .proof-item {
    padding: 14px 14px 14px 16px;
    border-radius: 18px;
    background: rgba(255,255,255,.03);
    border: 1px solid rgba(255,255,255,.06);
    border-inline-start: 3px solid rgba(0,229,255,.45);
  }
  .proof-item b {
    display: block;
    color: var(--white);
    margin-bottom: 6px;
    font-size: .92rem;
  }
  .outcome-card {
    background:
      linear-gradient(180deg, rgba(251,191,36,.08), rgba(255,255,255,.02)),
      rgba(12,10,22,.78);
    border-color: rgba(251,191,36,.16);
  }
  .proposal-frame {
    padding: 24px 0 6px;
  }
  .frame-head {
    margin-bottom: 24px;
    text-align: center;
  }
  .frame-head h2 {
    font-size: clamp(1.6rem, 3vw, 2.4rem);
    margin-bottom: 10px;
  }
  .frame-head p {
    max-width: 840px;
    margin: 0 auto;
  }
  .frame-grid { margin-bottom: 18px; }
  .proof-focus {
    background:
      linear-gradient(180deg, rgba(255,255,255,.055), rgba(255,255,255,.02)),
      rgba(11,16,30,.74);
  }
  .proof-focus .num-badge {
    box-shadow: 0 0 20px rgba(139,92,246,.26);
  }
  .cta-row {
    display: flex; gap: 14px; justify-content: center; flex-wrap: wrap;
    animation: fadeUp .9s .5s ease both;
  }
  .btn {
    border: none; cursor: pointer; text-decoration: none;
    padding: 16px 22px; border-radius: 24px; font-family: inherit; font-weight: 700;
    transition: .3s ease; display: inline-flex; align-items: center; gap: 12px;
    position: relative; overflow: hidden;
  }
  .btn::before {
    content: "";
    position: absolute; inset: 1px;
    border-radius: inherit;
    background: linear-gradient(180deg, rgba(255,255,255,.18), rgba(255,255,255,0));
    opacity: .45; pointer-events: none;
  }
  .btn::after {
    content: "";
    position: absolute; inset: -40%;
    background: linear-gradient(115deg, transparent 30%, rgba(255,255,255,.26) 50%, transparent 70%);
    transform: translateX(-65%) rotate(8deg);
    opacity: 0;
    transition: transform .8s ease, opacity .4s ease;
    pointer-events: none;
  }
  .btn:hover::after { transform: translateX(35%) rotate(8deg); opacity: 1; }
  .btn-label {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
    text-align: right;
    position: relative;
    z-index: 1;
  }
  .btn-label strong { font-size: .98rem; }
  .btn-label small {
    font-size: .72rem;
    font-weight: 500;
    opacity: .78;
  }
  .btn-icon {
    width: 36px; height: 36px;
    display: grid; place-items: center;
    border-radius: 14px;
    background: rgba(4,16,24,.14);
    position: relative; z-index: 1;
    box-shadow: inset 0 1px 0 rgba(255,255,255,.12);
  }
  .btn-primary {
    color: #031018;
    background:
      linear-gradient(135deg, rgba(255,255,255,.35), rgba(255,255,255,0) 34%),
      linear-gradient(135deg, var(--cyan), #67e8f9 48%, #c084fc 110%);
    box-shadow: 0 16px 42px rgba(0,229,255,.3), 0 0 0 1px rgba(255,255,255,.12) inset;
    transition: transform .25s cubic-bezier(.2,.8,.2,1), box-shadow .3s ease, background .3s ease;
  }
  .btn-primary:hover {
    transform: translate(var(--mag-x, 0px), var(--mag-y, 0px)) translateY(-3px) scale(1.03);
    box-shadow: 0 22px 50px rgba(0,229,255,.44), 0 0 28px rgba(192,132,252,.22);
  }
  .btn-ghost {
    color: var(--text);
    background: linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.03));
    border: 1px solid rgba(255,255,255,.08);
    box-shadow: inset 0 1px 0 rgba(255,255,255,.04);
  }
  .btn-ghost:hover {
    border-color: rgba(0,229,255,.4);
    background: linear-gradient(180deg, rgba(0,229,255,.12), rgba(255,255,255,.04));
    box-shadow: 0 16px 36px rgba(0,229,255,.12);
  }
  .cta-caption {
    margin-top: 18px;
    color: rgba(232,238,252,.72);
    font-size: .92rem;
    letter-spacing: .1px;
    animation: fadeUp .9s .58s ease both;
  }
  .trust-strip {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 26px;
  }
  .trust-chip {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    border-radius: 999px;
    background: rgba(255,255,255,.035);
    border: 1px solid rgba(255,255,255,.07);
    color: rgba(232,238,252,.82);
    font-size: .78rem;
    letter-spacing: .8px;
    font-family: "Space Grotesk", sans-serif;
    text-transform: uppercase;
    box-shadow: inset 0 1px 0 rgba(255,255,255,.04);
  }
  .trust-chip span {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--cyan), var(--violet));
    box-shadow: 0 0 14px rgba(0,229,255,.55);
  }
  .hero-deck {
    display: grid;
    grid-template-columns: 1.35fr .72fr .72fr;
    gap: 18px;
    margin-top: 34px;
    align-items: stretch;
    transform: translate3d(0, var(--deck-lift, 0), 0);
  }
  .hero-panel {
    position: relative;
    padding: 22px 22px 20px;
    border-radius: 24px;
    background:
      linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.02)),
      rgba(8,12,24,.62);
    border: 1px solid rgba(255,255,255,.08);
    backdrop-filter: blur(16px);
    text-align: right;
    box-shadow: var(--shadow);
    overflow: hidden;
  }
  .hero-panel::before {
    content: "";
    position: absolute;
    inset: auto -10% -45% auto;
    width: 180px; height: 180px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0,229,255,.2), transparent 68%);
    filter: blur(8px);
    pointer-events: none;
  }
  .hero-panel-main {
    border-color: rgba(0,229,255,.16);
    box-shadow: 0 24px 70px rgba(0,229,255,.12), var(--shadow);
  }
  .hero-panel-side.compact {
    display: flex;
    flex-direction: column;
    justify-content: center;
  }
  .panel-kicker {
    display: inline-flex;
    align-items: center;
    padding: 7px 12px;
    border-radius: 999px;
    background: rgba(0,229,255,.08);
    border: 1px solid rgba(0,229,255,.18);
    color: var(--cyan);
    font-family: "Space Grotesk", sans-serif;
    font-size: .72rem;
    letter-spacing: 1.1px;
    text-transform: uppercase;
    margin-bottom: 14px;
  }
  .hero-panel h3,
  .hero-panel h4 {
    font-size: 1.15rem;
    line-height: 1.6;
    margin-bottom: 10px;
  }
  .hero-panel p {
    color: rgba(232,238,252,.68);
    font-size: .9rem;
    line-height: 1.95;
  }
  .panel-metrics {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-top: 18px;
  }
  .panel-metric {
    padding: 14px 12px;
    border-radius: 18px;
    background: rgba(255,255,255,.03);
    border: 1px solid rgba(255,255,255,.06);
  }
  .panel-metric b {
    display: block;
    font-family: Orbitron, sans-serif;
    font-size: 1.15rem;
    color: var(--white);
    margin-bottom: 4px;
  }
  .panel-metric span {
    color: rgba(232,238,252,.62);
    font-size: .76rem;
  }
  .mini-doc {
    position: relative;
    min-height: 100%;
    padding: 18px;
    border-radius: 18px;
    background: linear-gradient(180deg, rgba(255,255,255,.05), rgba(255,255,255,.02));
    border: 1px solid rgba(255,255,255,.06);
    box-shadow: inset 0 1px 0 rgba(255,255,255,.05);
  }
  .mini-doc-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    margin-bottom: 16px;
    font-size: .78rem;
  }
  .mini-doc-top strong {
    font-family: "Space Grotesk", sans-serif;
    color: var(--white);
  }
  .mini-doc-top span {
    padding: 5px 9px;
    border-radius: 999px;
    background: rgba(34,211,166,.12);
    border: 1px solid rgba(34,211,166,.22);
    color: var(--lime);
    font-size: .68rem;
    letter-spacing: .9px;
  }
  .mini-bars {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    margin-bottom: 14px;
  }
  .mini-bars i,
  .mini-line {
    display: block;
    border-radius: 999px;
    background: linear-gradient(90deg, rgba(0,229,255,.9), rgba(139,92,246,.48));
    box-shadow: 0 0 18px rgba(0,229,255,.18);
  }
  .mini-bars i:nth-child(1) { height: 10px; width: 72%; }
  .mini-bars i:nth-child(2) { height: 10px; width: 92%; }
  .mini-bars i:nth-child(3) { height: 10px; width: 58%; }
  .mini-line {
    height: 12px;
    width: 100%;
    margin-bottom: 10px;
    opacity: .8;
  }
  .mini-line.short { width: 74%; opacity: .58; }
  .mini-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin-top: 18px;
  }
  .mini-grid span {
    padding: 10px 12px;
    border-radius: 14px;
    background: rgba(255,255,255,.03);
    border: 1px solid rgba(255,255,255,.05);
    color: rgba(232,238,252,.7);
    font-size: .78rem;
    text-align: center;
  }

  @keyframes fadeUp {
    from { opacity: 0; transform: translateY(28px); }
    to { opacity: 1; transform: translateY(0); }
  }

  /* sections */
  .wrap { width: min(1180px, calc(100% - 36px)); margin: 0 auto; }
  section.chapter {
    padding: 100px 0 40px;
    position: relative;
  }
  .chapter-head {
    display: flex; align-items: flex-end; justify-content: space-between; gap: 20px;
    margin-bottom: 34px; flex-wrap: wrap;
  }
  .chapter-num {
    font-family: Orbitron, sans-serif;
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 900; line-height: 1;
    background:
      radial-gradient(70% 60% at 50% var(--gp, 120%), rgba(0,229,255,.95), rgba(0,229,255,.15) 55%, transparent 78%),
      linear-gradient(180deg, rgba(0,229,255,.45), rgba(0,229,255,.06));
    -webkit-background-clip: text; background-clip: text; color: transparent;
    transform: translate3d(0, var(--num-y, 0), 0);
    filter: drop-shadow(0 0 14px rgba(0,229,255,.25));
    will-change: transform;
  }
  .chapter-title h2 {
    font-size: clamp(1.5rem, 3vw, 2.3rem);
    margin-bottom: 8px;
  }
  .chapter-title p { color: var(--muted); max-width: 560px; }
  .en-label {
    font-family: "Space Grotesk", sans-serif;
    color: var(--cyan); letter-spacing: 2px; font-size: 12px;
    margin-bottom: 6px; display: block;
  }

  .card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 26px;
    backdrop-filter: blur(12px);
    box-shadow: var(--shadow);
    position: relative; overflow: hidden;
    transition: .35s ease;
  }
  .card::before {
    content: ""; position: absolute; inset: 0; border-radius: inherit;
    background: radial-gradient(circle at var(--mx, 50%) var(--my, 50%),
                rgba(255,255,255,.16), rgba(0,229,255,.07) 38%, transparent 62%);
    opacity: 0; transition: opacity .35s ease; pointer-events: none; z-index: 0;
  }
  .card::after {
    content: "";
    position: absolute;
    inset: auto -15% -30% auto;
    width: 220px;
    height: 220px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(139,92,246,.12), transparent 70%);
    opacity: .55;
    pointer-events: none;
  }
  .card:hover { transform: translateY(-6px); border-color: rgba(0,229,255,.35); }
  .card:hover::before { opacity: .6; }
  .card > * { position: relative; z-index: 1; }

  .grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
  .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
  .grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
  @media (max-width: 960px) {
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .nav-links { display: none; }
  }
  @media (min-width: 700px) and (max-width: 960px) {
    .grid-2 { grid-template-columns: 1fr 1fr; }
    .grid-4 { grid-template-columns: 1fr 1fr; }
  }

  .reveal {
    opacity: 0; transform: translateY(40px) scale(.98);
    transition: opacity .8s cubic-bezier(.2,.8,.2,1) var(--rd, 0s),
                transform .8s cubic-bezier(.2,.8,.2,1);
  }
  .reveal.show { opacity: 1; transform: none; }

  .icon-box {
    width: 48px; height: 48px; border-radius: 14px;
    display: grid; place-items: center; font-size: 22px; margin-bottom: 14px;
    background: linear-gradient(135deg, rgba(0,229,255,.15), rgba(139,92,246,.15));
    border: 1px solid rgba(0,229,255,.2);
  }
  .card h3 { font-size: 1.15rem; margin-bottom: 10px; }
  .card p, .muted { color: var(--muted); font-size: .95rem; }
  ul.clean { list-style: none; display: grid; gap: 10px; }
  ul.clean li {
    padding: 10px 14px; border-radius: 12px;
    background: rgba(255,255,255,.03);
    border: 1px solid rgba(255,255,255,.04);
    display: flex; gap: 10px; align-items: flex-start;
  }
  ul.clean li::before {
    content: "◆"; color: var(--cyan); font-size: 10px; margin-top: 8px;
  }

  .pillars {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin: 24px 0;
  }
  @media (max-width: 900px) { .pillars { grid-template-columns: 1fr 1fr; } }
  @media (max-width: 560px) { .pillars { grid-template-columns: 1fr; } }
  .pillar {
    text-align: center; padding: 28px 16px;
    border-radius: 20px;
    border: 1px solid var(--line);
    background: rgba(10,16,32,.8);
    position: relative; overflow: hidden;
  }
  .pillar .roman {
    font-family: Orbitron, sans-serif;
    font-size: 2rem; font-weight: 900;
    background: linear-gradient(135deg, var(--cyan), var(--violet));
    -webkit-background-clip: text; background-clip: text; color: transparent;
  }
  .pillar h4 { margin: 10px 0 6px; font-size: 1rem; }
  .pillar p { font-size: .85rem; color: var(--muted); }
  .pillar::after {
    content: ""; position: absolute; bottom: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--cyan), var(--violet));
    transform: scaleX(0); transition: .4s ease; transform-origin: right;
  }
  .pillar:hover::after { transform: scaleX(1); transform-origin: left; }

  /* journey steps */
  .steps {
    display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; margin-top: 18px;
  }
  @media (max-width: 900px) { .steps { grid-template-columns: 1fr 1fr; } }
  .step {
    padding: 18px 14px; border-radius: 16px;
    background: rgba(0,229,255,.04);
    border: 1px solid rgba(0,229,255,.15);
    text-align: center;
  }
  .step .n {
    font-family: Orbitron, sans-serif; color: var(--cyan);
    font-size: 12px; letter-spacing: 1px; margin-bottom: 8px;
  }
  .step strong { display: block; font-size: .95rem; }

  /* layers */
  .layer {
    display: grid; grid-template-columns: 90px 1fr; gap: 16px; align-items: start;
    padding: 20px; border-radius: 18px;
    border: 1px solid var(--line);
    background:
      linear-gradient(180deg, rgba(255,255,255,.035), rgba(255,255,255,.015)),
      rgba(255,255,255,.02);
    margin-bottom: 12px;
    transition: .3s ease;
    position: relative;
    overflow: hidden;
  }
  .layer::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, transparent, rgba(0,229,255,.08), transparent);
    transform: translateX(-120%);
    transition: transform .8s ease;
    pointer-events: none;
  }
  .layer:hover {
    border-color: rgba(0,229,255,.35);
    background: rgba(0,229,255,.05);
    transform: translateX(-6px);
  }
  .layer:hover::before,
  .layer.is-active::before { transform: translateX(120%); }
  .layer .ln {
    font-family: Orbitron, sans-serif;
    font-size: 13px; color: #041018; font-weight: 800;
    background: linear-gradient(135deg, var(--cyan), var(--blue));
    border-radius: 12px; padding: 14px 8px; text-align: center;
    box-shadow: 0 8px 20px rgba(0,229,255,.25);
  }
  .layer h4 { margin-bottom: 6px; }
  .tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
  .tag {
    font-size: 12px; padding: 5px 10px; border-radius: 999px;
    background: rgba(139,92,246,.12); border: 1px solid rgba(139,92,246,.25);
    color: #c4b5fd;
  }

  .quote {
    margin: 28px 0;
    padding: 28px;
    border-radius: 22px;
    border: 1px solid rgba(251,191,36,.25);
    background: linear-gradient(135deg, rgba(251,191,36,.08), rgba(236,72,153,.05));
    position: relative;
  }
  .quote::before {
    content: "❝"; position: absolute; top: 8px; right: 20px;
    font-size: 48px; color: rgba(251,191,36,.35); font-family: serif;
  }
  .quote p { font-size: 1.1rem; font-weight: 500; }

  .value-grid .card { min-height: 180px; }
  .num-badge {
    width: 36px; height: 36px; border-radius: 50%;
    display: grid; place-items: center;
    background: linear-gradient(135deg, var(--violet), var(--pink));
    font-weight: 800; margin-bottom: 12px; font-size: 14px;
  }

  .stats {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin: 28px 0;
  }
  @media (max-width: 800px) { .stats { grid-template-columns: 1fr 1fr; } }
  .stat {
    text-align: center; padding: 24px 12px; border-radius: 18px;
    border: 1px solid rgba(255,255,255,.08);
    background:
      linear-gradient(180deg, rgba(255,255,255,.05), rgba(255,255,255,.02)),
      rgba(255,255,255,.03);
    box-shadow: inset 0 1px 0 rgba(255,255,255,.04);
  }
  .stat .v {
    font-family: Orbitron, sans-serif;
    font-size: 1.8rem; color: var(--cyan); margin-bottom: 6px;
  }
  .stat .l { font-size: .85rem; color: var(--muted); }

  .footer {
    margin-top: 60px; padding: 40px 0 60px;
    border-top: 1px solid var(--line);
    text-align: center; color: var(--muted); font-size: .9rem;
  }
  .footer .big {
    font-family: Orbitron, sans-serif; color: var(--white);
    letter-spacing: 2px; margin-bottom: 8px;
  }

  /* floating controls */
  .float-controls {
    position: fixed; left: 18px; bottom: 18px; z-index: 90;
    display: flex; flex-direction: column; gap: 8px;
  }
  .float-controls button {
    width: 46px; height: 46px; border-radius: 14px;
    border: 1px solid var(--line);
    background: rgba(8,12,24,.85); color: var(--text);
    cursor: pointer; backdrop-filter: blur(10px);
    transition: .25s ease; font-size: 16px;
  }
  .float-controls button:hover {
    border-color: var(--cyan); color: var(--cyan);
    box-shadow: 0 0 20px rgba(0,229,255,.25);
  }

  /* section divider line */
  .divider {
    height: 1px; margin: 40px 0;
    background: linear-gradient(90deg, transparent, rgba(0,229,255,.4), transparent);
  }

  .glow-text {
    text-shadow: 0 0 30px rgba(0,229,255,.35);
  }

  /* spotlight cards for ch2 sections */
  .section-list {
    display: grid; gap: 12px;
  }
  .section-item {
    display: grid; grid-template-columns: 8px 1fr; gap: 14px;
    padding: 16px 18px; border-radius: 16px;
    background: rgba(255,255,255,.025);
    border: 1px solid rgba(255,255,255,.05);
  }
  .section-item .bar {
    border-radius: 10px;
    background: linear-gradient(180deg, var(--cyan), var(--violet));
  }
  .section-item h4 { margin-bottom: 4px; }
  .section-item p { color: var(--muted); font-size: .9rem; }

  .marquee-wrap {
    overflow: hidden; margin: 30px 0; mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent);
  }
  .marquee {
    display: flex; gap: 14px; width: max-content;
    animation: marquee 28s linear infinite;
  }
  .marquee span {
    padding: 10px 18px; border-radius: 999px;
    border: 1px solid var(--line);
    background: rgba(255,255,255,.03);
    white-space: nowrap; color: var(--muted); font-size: 13px;
  }
  @keyframes marquee {
    from { transform: translateX(0); }
    to { transform: translateX(50%); }
  }

  .model-box {
    display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px;
  }
  @media (max-width: 800px) { .model-box { grid-template-columns: 1fr; } }
  .model {
    padding: 22px; border-radius: 18px; text-align: center;
    border: 1px solid var(--line);
    background: rgba(255,255,255,.03);
  }
  .model .abbr {
    font-family: Orbitron, sans-serif; color: var(--gold);
    font-size: 1.4rem; margin-bottom: 8px;
  }

  /* print / present helper */
  @media print {
    .topbar, .float-controls, .progress, #particles, .grid-overlay { display: none !important; }
    body { background: white; color: black; }
    .card { break-inside: avoid; box-shadow: none; border: 1px solid #ddd; }
  }

  /* ============================================================
     Living-Document layer · tilt surfaces, rail, ambient, a11y
     ============================================================ */

  /* custom scrollbar */
  html { scrollbar-color: var(--cyan) var(--bg2); scrollbar-width: thin; }
  ::-webkit-scrollbar { width: 10px; height: 10px; }
  ::-webkit-scrollbar-track { background: var(--bg2); }
  ::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--cyan), var(--violet));
    border-radius: 10px; border: 2px solid var(--bg2);
    box-shadow: 0 0 10px rgba(0,229,255,.4);
  }
  ::-webkit-scrollbar-thumb:hover { background: linear-gradient(180deg, var(--cyan), var(--pink)); }

  /* cursor-follow ambient spotlight */
  .cursor-spotlight {
    position: fixed; inset: 0; z-index: -1; pointer-events: none;
    background: radial-gradient(420px circle at var(--cx, 50%) var(--cy, 50%),
                rgba(0,229,255,.06), rgba(139,92,246,.03) 45%, transparent 70%);
  }

  /* .card gets a full transition list (wins over .reveal for .card.reveal);
     --rd staggers only the opacity fade so hover never lags */
  .card {
    transition: opacity .8s cubic-bezier(.2,.8,.2,1) var(--rd, 0s),
                transform .55s cubic-bezier(.2,.8,.2,1),
                border-color .35s ease, box-shadow .35s ease, background .35s ease;
  }

  /* ---------- 3D glass tilt: generic surfaces (pillar/stat/model/step/chip) ---------- */
  .tilt {
    position: relative;
    transform: perspective(900px) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg));
    transform-style: preserve-3d;
    transition: transform .5s cubic-bezier(.2,.8,.2,1),
                border-color .35s ease, box-shadow .35s ease, background .35s ease;
  }
  .tilt.tilt-active {
    will-change: transform;
    transition: border-color .35s ease, box-shadow .35s ease, background .35s ease;
  }
  .tilt::before {
    content: ""; position: absolute; inset: 0; border-radius: inherit;
    background: radial-gradient(circle at var(--mx, 50%) var(--my, 50%),
                rgba(255,255,255,.16), rgba(0,229,255,.07) 38%, transparent 62%);
    opacity: 0; transition: opacity .35s ease; pointer-events: none; z-index: 0;
  }
  .tilt:hover::before { opacity: .6; }
  .tilt.tilt-active::before { opacity: .55; }
  .tilt > * { position: relative; z-index: 1; }
  /* depth only on structural elements — never on paragraph text */
  .tilt .icon-box, .tilt .num-badge, .tilt .roman, .tilt .v, .tilt .abbr, .tilt .ln, .tilt .n {
    transform: translateZ(26px);
  }
  .tilt h3, .tilt h4 { transform: translateZ(14px); }

  /* ---------- 3D glass tilt: cards (override the hover-lift transform) ---------- */
  .card.tilt {
    overflow: visible;
    transform: perspective(900px) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg));
    transform-style: preserve-3d;
  }
  .card.tilt.tilt-active {
    will-change: transform;
    transition: opacity .8s cubic-bezier(.2,.8,.2,1),
                border-color .35s ease, box-shadow .35s ease, background .35s ease;
  }
  .card.tilt:hover {
    transform: perspective(900px) rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg)) translateY(-6px);
    border-color: rgba(0,229,255,.4);
    box-shadow: 0 26px 60px rgba(0,229,255,.18), var(--shadow-strong);
  }
  .card.tilt:hover::before { opacity: .65; }

  /* ---------- 9 revenue layers: scroll rail + active highlight ---------- */
  .layers { position: relative; }
  .layers::before {
    content: ""; position: absolute; inset-inline-start: 64px; top: 10px; bottom: 10px;
    width: 3px; border-radius: 3px; background: rgba(255,255,255,.08); z-index: 0;
  }
  .layers::after {
    content: ""; position: absolute; inset-inline-start: 64px; top: 10px; width: 3px;
    height: var(--rail-fill, 0%); border-radius: 3px;
    background: linear-gradient(180deg, var(--cyan), var(--violet), var(--pink));
    box-shadow: 0 0 14px rgba(0,229,255,.6); z-index: 0; transition: height .12s linear;
  }
  .layer { position: relative; z-index: 1; }
  .layer.is-active {
    border-color: rgba(0,229,255,.5);
    background: rgba(0,229,255,.07);
    transform: translateX(-6px) scale(1.012);
    box-shadow: 0 14px 40px rgba(0,229,255,.14);
  }
  .layer.is-active .ln { box-shadow: 0 0 26px rgba(0,229,255,.65), 0 8px 20px rgba(0,229,255,.3); }
  .layer.is-active h4 { color: var(--white); }

  .closing-strip {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 18px;
  }
  .closing-chip {
    padding: 10px 14px;
    border-radius: 999px;
    background: rgba(255,255,255,.04);
    border: 1px solid rgba(255,255,255,.08);
    color: rgba(232,238,252,.76);
    font-size: .77rem;
    font-family: "Space Grotesk", sans-serif;
    letter-spacing: .7px;
  }

  /* ---------- staggered reveal cascade (opacity-only delay → no hover lag) ---------- */
  .grid-2 .reveal:nth-child(2),
  .grid-3 .reveal:nth-child(2),
  .grid-4 .reveal:nth-child(2) { --rd: .08s; }
  .grid-3 .reveal:nth-child(3),
  .grid-4 .reveal:nth-child(3) { --rd: .16s; }
  .grid-4 .reveal:nth-child(4) { --rd: .24s; }

  /* ---------- reduced motion: full, readable fallback ---------- */
  @media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
      animation-duration: .001ms !important; animation-iteration-count: 1 !important;
      transition-duration: .001ms !important; scroll-behavior: auto !important;
    }
    .reveal { opacity: 1 !important; transform: none !important; }
    .tilt, .card.tilt { transform: none !important; }
    .tilt::before, .card::before, .cursor-spotlight, .grid-overlay, #particles { display: none !important; }
    .chapter-num { transform: none !important; filter: none !important; }
    .marquee, .hero-orb, .logo { animation: none !important; }
  }

  @media (max-width: 1100px) {
    .logic-flow,
    .claim-grid { grid-template-columns: 1fr; }
    .hero-deck { grid-template-columns: 1fr; }
  }
  @media (max-width: 760px) {
    .hero::before { inset-inline: 6%; height: 340px; }
    .btn { width: 100%; justify-content: space-between; }
    .cta-row { width: min(620px, 100%); margin-inline: auto; }
    .trust-strip { gap: 10px; }
    .panel-metrics { grid-template-columns: 1fr; }
    .logic-flow { gap: 10px; }
  }