/* ============ DESIGN TOKENS ============ */
    :root {
      --bg: #ffffff;
      --bg-elev: #ffffff;
      --bg-card: #ffffff;
      --bg-card-hover: #ffffff;
      --border: rgba(15, 23, 42, 0.12);
      --border-strong: rgba(15, 23, 42, 0.18);

      --text: #0f172a;
      --text-dim: #334155;
      --text-muted: #64748b;

      --electric: #3b82f6;
      --electric-bright: #60a5fa;
      --electric-glow: rgba(59, 130, 246, 0.35);

      --amber: #f59e0b;
      --amber-bright: #fbbf24;
      --amber-glow: rgba(245, 158, 11, 0.3);

      --success: #10b981;
      --danger: #ef4444;

      --font-display: 'Fraunces', Georgia, serif;
      --font-body: 'IBM Plex Sans', system-ui, sans-serif;
      --font-mono: 'IBM Plex Mono', monospace;

      --max-w: 1200px;
      --gap: clamp(1rem, 2vw, 1.5rem);
      --radius: 10px;
      --radius-lg: 16px;
    }

    /* ============ RESET ============ */
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
      background: var(--bg);
      color: var(--text);
      font-family: var(--font-body);
      font-weight: 400;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      /* clip (not hidden) prevents a horizontal scrollbar WITHOUT creating a
         scroll container — so .section-nav position:sticky keeps working. */
      overflow-x: clip;
    }
    img, svg { max-width: 100%; display: block; }
    a { color: var(--electric-bright); text-decoration: none; }

    /* ============ ATMOSPHERIC BACKGROUND ============ */
    body::before,
    body::after {
      content: none;
      display: none;
    }

    /* ============ HERO REPLACEMENT (CAROUSEL EMBED) ============ */
    .carousel-embed {
      position: relative;
      z-index: 1;
      /* Offset for fixed .nav from styles.css */
      padding: 80px 0 0;
      margin: 0;
    }
    .carousel-embed__inner {
      max-width: none;
      margin: 0;
      border-radius: 0;
      overflow: hidden;
      border: 0;
      background: #ffffff;
      box-shadow: none;
    }
    .carousel-embed__frame {
      width: 100%;
      height: clamp(545px, 74vh, 760px);
      border: 0;
      display: block;
      background: #ffffff;
    }
    @media (max-width: 720px) {
      .carousel-embed__frame { height: clamp(475px, 70vh, 700px); }
    }

    /* ============ SECTION NAV ============ */
    .section-nav {
      position: sticky;
      top: 78px;
      z-index: 999;
      margin-top: 0;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-top: 1px solid var(--border);
      border-bottom: 1px solid var(--border);
    }
    .section-nav-inner {
      max-width: var(--max-w);
      margin: 0 auto;
      padding: 0.75rem 2rem;
      display: flex; flex-wrap: wrap; gap: 0.25rem;
      justify-content: center;
      overflow-x: auto;
      scrollbar-width: none;
    }
    .section-nav-inner::-webkit-scrollbar { display: none; }
    .section-nav a {
      padding: 0.5rem 1rem;
      font-family: var(--font-mono);
      font-size: 0.75rem;
      letter-spacing: 0.05em;
      text-transform: uppercase;
      color: var(--text-dim);
      border-radius: 999px;
      transition: all 0.2s;
      white-space: nowrap;
      flex-shrink: 0;
    }
    .section-nav a:hover {
      color: var(--text);
      background: var(--bg-elev);
    }
    .section-nav a.active {
      color: var(--electric-bright);
      background: rgba(59, 130, 246, 0.12);
    }
    @media (max-width: 720px) {
      .section-nav-inner { padding: 0.5rem 1rem; justify-content: flex-start; }
      .section-nav a { padding: 0.5rem 0.75rem; font-size: 0.6875rem; }
    }

    /* Scroll-margin so anchor jumps clear the sticky navs */
    section.content {
      scroll-margin-top: 130px;
    }
    @media (max-width: 720px) {
      section.content { scroll-margin-top: 170px; }
    }
    @media (max-width: 480px) {
      section.content { scroll-margin-top: 200px; }
    }

    /* ============ SECTION ============ */
    section.content {
      max-width: var(--max-w);
      margin: 0 auto;
      padding: clamp(2.25rem, 4.5vw, 3.75rem) 2rem;
      position: relative;
      z-index: 1;
    }
    section.content#challenge,
    section.content#solution,
    section.content#demo,
    section.content#architecture,
    section.content#models,
    section.content#results {
      padding-bottom: 0;
    }
    .section-kicker {
      font-family: var(--font-mono);
      font-size: 0.6875rem;
      letter-spacing: 0.18em;
      text-transform: uppercase;
      color: var(--amber);
      margin-bottom: 1.25rem;
      display: flex; align-items: center; gap: 0.75rem;
    }
    .section-kicker::before {
      content: '';
      width: 30px; height: 1px;
      background: var(--amber);
    }
    .section-title {
      font-family: var(--font-display);
      font-weight: 500;
      font-size: clamp(1.875rem, 3.5vw, 2.5rem);
      line-height: 1.15;
      letter-spacing: -0.02em;
      margin-bottom: 2rem;
      max-width: 800px;
    }
    .section-lede {
      font-size: 1.125rem;
      line-height: 1.7;
      color: var(--text-dim);
      max-width: 760px;
      margin-bottom: 2.5rem;
    }
    .section-prose p {
      font-size: 1rem;
      line-height: 1.75;
      color: var(--text-dim);
      max-width: 760px;
      margin-bottom: 1.5rem;
    }
    .section-prose p strong {
      color: var(--text);
      font-weight: 500;
    }

    /* ============ CHALLENGE LIST ============ */
    .challenge-list {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 1.5rem;
      margin-top: 2rem;
    }
    .challenge-item {
      padding: 1.5rem;
      background: var(--bg-elev);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      transition: all 0.25s;
    }
    .challenge-item:hover {
      border-color: var(--border-strong);
      background: var(--bg-card);
      transform: translateY(-2px);
    }
    .challenge-item h4 {
      font-family: var(--font-display);
      font-size: 1.125rem;
      font-weight: 500;
      color: var(--text);
      margin-bottom: 0.625rem;
    }
    .challenge-item p {
      font-size: 0.9375rem;
      line-height: 1.6;
      color: var(--text-dim);
    }
    @media (max-width: 720px) {
      .challenge-list { grid-template-columns: 1fr; }
    }

    /* ============ PROJECT DEMO ============ */
    .demo-wrapper {
      margin-top: 2.5rem;
      position: relative;
    }
    .demo-video {
      position: relative;
      aspect-ratio: 16 / 9;
      background: linear-gradient(135deg, var(--bg-elev), var(--bg-card));
      border: 1px solid var(--border-strong);
      border-radius: var(--radius-lg);
      overflow: hidden;
      cursor: pointer;
      transition: transform 0.3s, border-color 0.3s;
    }
    .demo-video:hover {
      transform: translateY(-2px);
      border-color: rgba(96, 165, 250, 0.4);
    }
    .demo-video::before {
      content: none;
      display: none;
    }
    .demo-video video,
    .demo-video iframe {
      position: absolute; inset: 0;
      width: 100%; height: 100%;
      border: 0;
    }
    .demo-placeholder {
      position: absolute; inset: 0;
      display: flex; flex-direction: column; align-items: center; justify-content: center;
      gap: 1.5rem;
      text-align: center;
      padding: 2rem;
    }
    .demo-play {
      width: 84px; height: 84px;
      border-radius: 50%;
      background: var(--electric);
      display: grid; place-items: center;
      box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.5);
      animation: demoPulse 2.5s ease-out infinite;
      transition: transform 0.2s, background 0.2s;
    }
    .demo-video:hover .demo-play {
      background: var(--electric-bright);
      transform: scale(1.06);
    }
    .demo-play svg {
      width: 32px; height: 32px;
      fill: white;
      margin-left: 4px;
    }
    @keyframes demoPulse {
      0% { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.45); }
      70% { box-shadow: 0 0 0 24px rgba(59, 130, 246, 0); }
      100% { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0); }
    }
    .demo-eyebrow {
      font-family: var(--font-mono);
      font-size: 0.6875rem;
      letter-spacing: 0.18em;
      text-transform: uppercase;
      color: var(--amber);
    }
    .demo-headline {
      font-family: var(--font-display);
      font-weight: 500;
      font-size: clamp(1.125rem, 2vw, 1.375rem);
      color: var(--text);
      max-width: 560px;
      line-height: 1.35;
    }
    .demo-sub {
      font-size: 0.875rem;
      color: var(--text-dim);
      max-width: 440px;
    }
    .demo-meta {
      display: flex; flex-wrap: wrap; gap: 1.5rem;
      margin-top: 1.5rem;
      padding-top: 1.5rem;
      border-top: 1px solid var(--border);
      font-family: var(--font-mono);
      font-size: 0.75rem;
      color: var(--text-muted);
    }
    .demo-meta-item { display: flex; align-items: center; gap: 0.5rem; }
    .demo-meta-dot {
      width: 6px; height: 6px;
      border-radius: 50%;
      background: var(--electric);
    }
    @media (prefers-reduced-motion: reduce) {
      .demo-play { animation: none; }
    }

    /* ============ ARCHITECTURE DIAGRAM ============ */
    /* Hidden on product pages — diagram suppressed by request. */
    .arch-wrapper { display: none; }
    .arch-wrapper--legacy {
      margin-top: 3rem;
      padding: 1.5rem;
      background: linear-gradient(180deg, var(--bg-elev), var(--bg-card));
      border: 1px solid var(--border-strong);
      border-radius: var(--radius-lg);
      position: relative;
      overflow: hidden;
    }
    .arch-wrapper::before {
      content: none;
      display: none;
    }
    .arch-svg-frame {
      position: relative;
      background: #ffffff;
      border-radius: var(--radius);
      padding: 1rem;
      overflow: auto;
    }
    .arch-svg-frame svg {
      width: 100%;
      height: auto;
      min-width: 0;
    }
    .arch-caption {
      font-family: var(--font-mono);
      font-size: 0.75rem;
      letter-spacing: 0.05em;
      color: var(--text-muted);
      margin-top: 1rem;
      text-align: center;
    }

    /* ============ ARCHITECTURE STEPS ============ */
    .arch-steps {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      gap: 1rem;
      margin-top: 3rem;
    }
    .arch-step {
      padding: 1.25rem 1rem;
      background: var(--bg-elev);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      position: relative;
    }
    .arch-step-num {
      font-family: var(--font-mono);
      font-size: 0.75rem;
      color: var(--electric-bright);
      letter-spacing: 0.1em;
      margin-bottom: 0.625rem;
    }
    .arch-step-title {
      font-family: var(--font-display);
      font-weight: 500;
      font-size: 1rem;
      color: var(--text);
      margin-bottom: 0.5rem;
      line-height: 1.3;
    }
    .arch-step-desc {
      font-size: 0.8125rem;
      line-height: 1.55;
      color: var(--text-dim);
    }
    @media (max-width: 980px) {
      .arch-steps { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 520px) {
      .arch-steps { grid-template-columns: 1fr; }
    }

    /* ============ MODEL FAMILIES ============ */
    .models {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.25rem;
      margin-top: 2.5rem;
    }
    .model-card {
      padding: 2rem 1.75rem;
      background: var(--bg-elev);
      border: 1px solid var(--border);
      border-radius: var(--radius-lg);
      position: relative;
      overflow: hidden;
    }
    .model-card::before {
      content: '';
      position: absolute;
      top: 0; left: 0; right: 0; height: 3px;
      background: var(--electric);
    }
    .model-card:nth-child(2)::before { background: var(--amber); }
    .model-card:nth-child(3)::before { background: var(--electric-bright); }
    .model-card-tag {
      font-family: var(--font-mono);
      font-size: 0.6875rem;
      letter-spacing: 0.1em;
      text-transform: uppercase;
      color: var(--text-muted);
      margin-bottom: 0.5rem;
    }
    .model-card h4 {
      font-family: var(--font-display);
      font-weight: 500;
      font-size: 1.5rem;
      letter-spacing: -0.01em;
      color: var(--text);
      margin-bottom: 1rem;
    }
    .model-card p {
      font-size: 0.9375rem;
      line-height: 1.65;
      color: var(--text-dim);
    }
    @media (max-width: 900px) {
      .models { grid-template-columns: 1fr; }
    }

    /* ============ IMPACT GRID ============ */
    .impact-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.5rem;
      margin-top: 2.5rem;
    }
    .impact-card {
      padding: 2rem;
      background: linear-gradient(180deg, var(--bg-elev), var(--bg-card));
      border: 1px solid var(--border);
      border-radius: var(--radius-lg);
    }
    .impact-card h4 {
      font-family: var(--font-display);
      font-weight: 500;
      font-size: 1.25rem;
      color: var(--text);
      margin-bottom: 1.25rem;
      padding-bottom: 1rem;
      border-bottom: 1px solid var(--border);
    }
    .impact-card ul {
      list-style: none;
    }
    .impact-card li {
      font-size: 0.9375rem;
      line-height: 1.6;
      color: var(--text-dim);
      padding-left: 1.25rem;
      margin-bottom: 0.75rem;
      position: relative;
    }
    .impact-card li::before {
      content: '';
      position: absolute;
      left: 0; top: 0.6rem;
      width: 6px; height: 6px;
      background: var(--electric);
      border-radius: 50%;
    }
    @media (max-width: 900px) {
      .impact-grid { grid-template-columns: 1fr; }
    }

    /* ============ FAQ ============ */
    .faq-list {
      margin-top: 2rem;
    }
    details.faq {
      border-bottom: 1px solid var(--border);
      padding: 1.5rem 0;
      transition: all 0.2s;
    }
    details.faq[open] {
      border-bottom-color: var(--border-strong);
    }
    details.faq summary {
      list-style: none;
      cursor: pointer;
      display: flex; align-items: flex-start; gap: 1.25rem;
      font-family: var(--font-display);
      font-size: 1.125rem;
      font-weight: 500;
      color: var(--text);
      line-height: 1.4;
      transition: color 0.2s;
    }
    details.faq summary::-webkit-details-marker { display: none; }
    details.faq summary::marker { display: none; }
    details.faq summary:hover { color: var(--electric-bright); }
    .faq-icon {
      flex-shrink: 0;
      width: 24px; height: 24px;
      border: 1px solid var(--border-strong);
      border-radius: 50%;
      display: grid; place-items: center;
      position: relative;
      margin-top: 0.125rem;
      transition: all 0.2s;
    }
    .faq-icon::before, .faq-icon::after {
      content: '';
      position: absolute;
      background: var(--text-dim);
      transition: all 0.2s;
    }
    .faq-icon::before { width: 10px; height: 1.5px; }
    .faq-icon::after { width: 1.5px; height: 10px; }
    details.faq[open] .faq-icon::after { transform: rotate(90deg); opacity: 0; }
    details.faq[open] .faq-icon { background: var(--electric); border-color: var(--electric); }
    details.faq[open] .faq-icon::before { background: white; }
    .faq-answer {
      margin-top: 1rem;
      padding-left: calc(24px + 1.25rem);
      font-size: 1rem;
      line-height: 1.7;
      color: var(--text-dim);
    }

    /* ============ CTA ============
       Centering scoped under body.product-page (CSS nesting) so it cannot
       leak onto other routes' CTAs after client-side navigation. Each
       /products/* page mounts <BodyClass className="product-page" />,
       so the CTA renders centered on those routes only.
       Other selectors (sizing/padding/colors) stay un-scoped — they were
       never causing the centering leak. */
    body.product-page {
      .cta-band {
        margin-left: auto;
        margin-right: auto;
      }
      .cta-inner {
        text-align: center;
      }
      .cta-title {
        margin-left: auto;
        margin-right: auto;
      }
      .cta-sub {
        margin-left: auto;
        margin-right: auto;
      }
      .cta-actions {
        justify-content: center;
      }
    }
    .cta-band {
      max-width: var(--max-w);
      margin-top: 0;
      margin-bottom: 6rem;
      padding: 0 2rem;
      position: relative;
      z-index: 1;
    }
    .cta-inner {
      padding: clamp(2.5rem, 5vw, 4rem);
      background: #ffffff;
      border: 1px solid var(--border-strong);
      border-radius: var(--radius-lg);
      position: relative;
      overflow: hidden;
    }
    .cta-inner::before {
      content: none;
      display: none;
    }
    .cta-inner > * { position: relative; }
    .cta-eyebrow {
      font-family: var(--font-mono);
      font-size: 0.75rem;
      letter-spacing: 0.15em;
      text-transform: uppercase;
      color: var(--text-muted);
      margin-bottom: 1rem;
    }
    .cta-title {
      font-family: var(--font-display);
      font-weight: 500;
      font-size: clamp(1.75rem, 3vw, 2.25rem);
      line-height: 1.2;
      color: var(--text);
      max-width: 700px;
      margin: 0 0 1.5rem;
      letter-spacing: -0.02em;
    }
    .cta-sub {
      font-size: 1.0625rem;
      color: var(--text-dim);
      max-width: 600px;
      margin: 0 0 2.5rem;
      line-height: 1.6;
    }
    .cta-actions {
      display: flex; flex-wrap: wrap; gap: 1rem;
    }
    .cta-actions .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 0.875rem 1.75rem;
      border-radius: 10px;
      font-family: var(--font-body);
      font-size: 0.9375rem;
      font-weight: 600;
      border: 1px solid transparent;
      transition: all 0.2s;
    }
    .cta-actions .btn.btn-primary {
      background: #f58a22 !important;
      border-color: #f58a22 !important;
      color: #ffffff !important;
    }
    .cta-actions .btn.btn-primary:hover {
      background: #d97718 !important;
      border-color: #d97718 !important;
      transform: translateY(-1px);
    }
    .cta-actions .btn.btn-ghost {
      background: #ffffff;
      color: var(--text);
      border-color: var(--border-strong);
    }
    .cta-actions .btn.btn-ghost:hover {
      background: var(--bg-card-hover);
      transform: translateY(-1px);
    }
/* ============ SCROLL ANIMATIONS ============ */
    .reveal {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .reveal.visible {
      opacity: 1;
      transform: translateY(0);
    }
    @media (prefers-reduced-motion: reduce) {
      .reveal { opacity: 1; transform: none; transition: none; }
      html { scroll-behavior: auto; }
    }

    /* ============ HIGHLIGHT TAGS ============ */
    .tech-tags {
      display: flex; flex-wrap: wrap; gap: 0.5rem;
      margin-top: 2rem;
    }
    .tech-tag {
      padding: 0.375rem 0.875rem;
      font-family: var(--font-mono);
      font-size: 0.75rem;
      letter-spacing: 0.05em;
      background: var(--bg-elev);
      border: 1px solid var(--border-strong);
      border-radius: 999px;
      color: var(--text-dim);
    }
    .tech-tag.accent {
      color: var(--electric-bright);
      border-color: rgba(96, 165, 250, 0.4);
    }