:root {
    --navy: #070e1a;
    --navy-mid: #0d1f38;
    --navy-light: #132844;
    --ink: #0f172a;
    --slate: #334155;
    --muted: #64748b;
    --border: #1e3a5f;
    --border-light: #e2e8f0;
    --off-white: #f7f4ef;
    --white: #fff;
    --red: #dc2626;
    --red-light: #fef2f2;
    --red-mid: #fee2e2;
    --green: #16a34a;
    --green-light: #f0fdf4;
    --blue: #2563eb;
    --blue-light: #eff6ff;
    --amber: #d97706;
    --amber-light: #fffbeb;
    --purple: #7c3aed;
    --accent-glow: rgb(37 99 235 / 0.15);
    --font-display: 'Playfair Display', georgia, serif;
    --font-body: 'Instrument Sans', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
  }

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

  html {
    scroll-behavior: smooth;
    font-size: 16px;
  }

  body {
    font-family: var(--font-body);
    background: var(--off-white);
    color: var(--ink);
    line-height: 1.7;
    overflow-x: hidden;
  }

  /* ── PROGRESS BAR ── */
  #progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    width: 0%;
    background: linear-gradient(90deg, var(--blue), var(--purple));
    z-index: 1000;
    transition: width 0.1s linear;
  }

  .nav-links a:hover {
    color: #e2e8f0;
  }

  /* ── HERO ── */
  .hero {
    background: var(--navy);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 100px 2rem 80px;
    position: relative;
    overflow: hidden;
  }

  .hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
      radial-gradient(ellipse 80% 60% at 20% 50%, rgb(37 99 235 / 0.12) 0%, transparent 60%),
      radial-gradient(ellipse 60% 80% at 80% 20%, rgb(220 38 38 / 0.08) 0%, transparent 50%);
    pointer-events: none;
  }

  .hero-grid {
    position: absolute;
    inset: 0;
    opacity: 0.04;
    background-image: linear-gradient(rgb(255 255 255 / 0.5) 1px, transparent 1px),
      linear-gradient(90deg, rgb(255 255 255 / 0.5) 1px, transparent 1px);
    background-size: 60px 60px;
  }

  .hero-inner {
    max-width: 1100px;
    margin: 0 auto;
    width: 100%;
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
  }

  .hero-text-content {
    flex: 1;
    width: 100%;
    text-align: left;
  }

  .hero-eyebrow {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: #60a5fa;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
  }

  @media (width <= 1024px) {
    .hero-inner {
      gap: 3rem;
      text-align: center;
      align-items: center;
    }

    .hero-text-content {
      text-align: center;
    }

    .hero-eyebrow {
      justify-content: center;
    }
  }

  .hero-eyebrow::before {
    content: '';
    display: block;
    width: 40px;
    height: 1px;
    background: #60a5fa;
  }

  .hero h1 {
    font-family: var(--font-display);
    font-size: clamp(2.4rem, 6vw, 5rem);
    font-weight: 900;
    line-height: 1.08;
    color: var(--white);
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
  }

  .hero h1 em {
    font-style: italic;
    color: #93c5fd;
  }

  .hero-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    color: #94a3b8;
    max-width: 620px;
    margin-bottom: 2.5rem;
    font-weight: 400;
  }

  .hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 3rem;
  }

  .badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.3rem 0.8rem;
    border-radius: 999px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 500;
    letter-spacing: 0.03em;
    border: 1px solid;
  }

  .badge-blue {
    background: rgb(37 99 235 / 0.15);
    border-color: rgb(37 99 235 / 0.4);
    color: #93c5fd;
  }

  .badge-green {
    background: rgb(22 163 74 / 0.15);
    border-color: rgb(22 163 74 / 0.4);
    color: #86efac;
  }

  .badge-red {
    background: rgb(220 38 38 / 0.15);
    border-color: rgb(220 38 38 / 0.4);
    color: #fca5a5;
  }

  .badge-amber {
    background: rgb(217 119 6 / 0.15);
    border-color: rgb(217 119 6 / 0.4);
    color: #fcd34d;
  }

  .badge-purple {
    background: rgb(124 58 237 / 0.15);
    border-color: rgb(124 58 237 / 0.4);
    color: #c4b5fd;
  }

  .hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1px;
    background: var(--border);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    max-width: 640px;
  }

  .hero-stat {
    background: var(--navy-light);
    padding: 1.25rem 1.5rem;
    text-align: center;
  }

  .hero-stat-val {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    color: var(--white);
    line-height: 1;
    margin-bottom: 0.3rem;
  }

  .hero-stat-val.green {
    color: #4ade80;
  }

  .hero-stat-val.blue {
    color: #60a5fa;
  }

  .hero-stat-val.red {
    color: #f87171;
  }

  .hero-stat-label {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: #64748b;
    font-family: var(--font-mono);
  }

  .hero-scroll {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: #475569;
    font-size: 0.7rem;
    font-family: var(--font-mono);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    animation: bounce 2s infinite;
  }

  @keyframes bounce {
    0%,
    100% {
      transform: translateX(-50%) translateY(0)
    }

    50% {
      transform: translateX(-50%) translateY(8px)
    }
  }

  .scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid #475569;
    border-bottom: 2px solid #475569;
    transform: rotate(45deg);
  }

  /* ── SECTIONS ── */
  section {
    padding: 5rem 2rem;
  }

  .section-inner {
    max-width: 1100px;
    margin: 0 auto;
  }

  .section-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--blue);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
  }

  .section-label::after {
    content: '';
    flex: 0 0 32px;
    height: 1px;
    background: var(--blue);
  }

  h2.section-title {
    font-family: var(--font-display);
    font-size: clamp(1.8rem, 4vw, 3rem);
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.02em;
    color: var(--ink);
    margin-bottom: 1rem;
  }

  h2.section-title em {
    font-style: italic;
    color: var(--blue);
  }

  .section-lead {
    font-size: 1.05rem;
    color: var(--slate);
    max-width: 680px;
    margin-bottom: 3rem;
    line-height: 1.75;
  }

  /* ── DARK SECTION ── */
  .section-dark {
    background: var(--navy);
    color: var(--white);
  }

  .section-dark h2.section-title {
    color: var(--white);
  }

  .section-dark .section-lead {
    color: #94a3b8;
  }

  .section-dark .section-label {
    color: #60a5fa;
  }

  .section-dark .section-label::after {
    background: #60a5fa;
  }

  /* ── EXECUTIVE SUMMARY ── */
  .exec-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    align-items: start;
  }

  @media (width <= 768px) {
    .exec-grid {
      grid-template-columns: 1fr;
    }
  }

  .exec-text p {
    color: var(--slate);
    margin-bottom: 1rem;
    line-height: 1.8;
  }

  .system-glance {
    background: var(--navy);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid var(--border);
    position: relative;
    overflow: hidden;
  }

  .system-glance::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--blue), var(--purple), var(--red));
  }

  .glance-title {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: #60a5fa;
    margin-bottom: 1.5rem;
  }

  .glance-pipeline {
    display: flex;
    flex-direction: column;
    gap: 0;
  }

  .pipeline-row {
    display: grid;
    grid-template-columns: 90px 1fr;
    gap: 1rem;
    align-items: start;
    padding: 0.75rem 0;
    border-bottom: 1px solid rgb(255 255 255 / 0.07);
  }

  .pipeline-row:last-child {
    border-bottom: none;
  }

  .pipeline-key {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    color: #475569;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    padding-top: 0.1rem;
  }

  .pipeline-val {
    font-size: 0.88rem;
    color: #e2e8f0;
    font-weight: 500;
  }

  .pipeline-val .tag {
    display: inline-block;
    background: rgb(37 99 235 / 0.2);
    color: #93c5fd;
    border-radius: 4px;
    padding: 0.1rem 0.4rem;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    margin-left: 0.4rem;
  }

  /* ── PROBLEM SECTION ── */
  .problem-tension {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 1.5rem;
    align-items: center;
    margin-bottom: 3rem;
  }

  @media (width <= 600px) {
    .problem-tension {
      grid-template-columns: 1fr;
      text-align: center;
    }

    .tension-vs {
      display: none;
    }
  }

  .tension-card {
    border-radius: 12px;
    padding: 1.75rem;
    border: 1px solid;
  }

  .tension-card.fn {
    background: var(--red-light);
    border-color: #fecaca;
  }

  .tension-card.fp {
    background: var(--amber-light);
    border-color: #fde68a;
  }

  .tension-icon {
    font-size: 2rem;
    margin-bottom: 0.75rem;
  }

  .tension-title {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
  }

  .tension-card.fn .tension-title {
    color: var(--red);
  }

  .tension-card.fp .tension-title {
    color: var(--amber);
  }

  .tension-desc {
    font-size: 0.88rem;
    color: var(--slate);
    line-height: 1.6;
  }

  .tension-vs {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 900;
    color: #94a3b8;
    font-style: italic;
  }



  .check {
    color: var(--green);
    font-size: 1.1rem;
    margin-right: 0.3rem;
  }

  .cross {
    color: var(--red);
    font-size: 1.1rem;
    margin-right: 0.3rem;
  }

  /* ── DATASET ── */
  .dataset-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
  }

  .ds-card {
    border-radius: 12px;
    padding: 1.5rem;
    border: 1px solid var(--border-light);
    background: var(--white);
    box-shadow: 0 1px 4px rgb(0 0 0 / 0.04);
    transition: transform 0.2s, box-shadow 0.2s;
  }

  .ds-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgb(0 0 0 / 0.08);
  }

  .ds-icon {
    font-size: 1.75rem;
    margin-bottom: 0.75rem;
  }

  .ds-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 0.25rem;
  }

  .ds-value {
    font-family: var(--font-display);
    font-size: 1.9rem;
    font-weight: 700;
    color: var(--ink);
    line-height: 1;
    margin-bottom: 0.3rem;
  }

  .ds-desc {
    font-size: 0.85rem;
    color: var(--slate);
  }

  /* Donut chart */
  .donut-wrap {
    background: var(--white);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 2rem;
    display: flex;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
    margin-bottom: 3rem;
    box-shadow: 0 1px 4px rgb(0 0 0 / 0.04);
  }

  .donut-svg {
    flex: 0 0 160px;
  }

  .donut-legend {
    display: flex;
    flex-direction: column;
    gap: 1rem;
  }

  .legend-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
  }

  .legend-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    flex-shrink: 0;
  }

  .legend-info .legend-name {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--ink);
  }

  .legend-info .legend-count {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--muted);
  }

  /* Feature groups */
  .feature-groups {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }

  @media (width <= 768px) {
    .feature-groups {
      grid-template-columns: 1fr;
    }
  }

  .fg-card {
    border-radius: 12px;
    padding: 1.5rem;
    border-top: 3px solid;
  }

  .fg-card.mean {
    border-color: var(--blue);
    background: var(--blue-light);
  }

  .fg-card.se {
    border-color: var(--amber);
    background: var(--amber-light);
  }

  .fg-card.worst {
    border-color: var(--red);
    background: var(--red-light);
  }

  .fg-title {
    font-weight: 700;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
    color: var(--ink);
  }

  .fg-badge {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.68rem;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    margin-bottom: 0.75rem;
  }

  .fg-card.mean .fg-badge {
    background: rgb(37 99 235 / 0.15);
    color: var(--blue);
  }

  .fg-card.se .fg-badge {
    background: rgb(217 119 6 / 0.15);
    color: var(--amber);
  }

  .fg-card.worst .fg-badge {
    background: rgb(220 38 38 / 0.15);
    color: var(--red);
  }

  .fg-features {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
  }

  .fg-features li {
    font-size: 0.78rem;
    color: var(--slate);
    background: rgb(255 255 255 / 0.7);
    border: 1px solid rgb(0 0 0 / 0.06);
    border-radius: 4px;
    padding: 0.15rem 0.5rem;
  }

  /* ── ARCHITECTURE PIPELINE ── */
  .pipeline-visual {
    display: flex;
    align-items: stretch;
    gap: 0;
    overflow-x: auto;
    padding-bottom: 1rem;
    margin-bottom: 3rem;
  }

  .pipe-step {
    flex: 1 1 140px;
    min-width: 130px;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 1.5rem 1rem;
    background: var(--navy-light);
    border: 1px solid var(--border);
    position: relative;
  }

  .pipe-step:first-child {
    border-radius: 12px 0 0 12px;
  }

  .pipe-step:last-child {
    border-radius: 0 12px 12px 0;
  }

  .pipe-step+.pipe-step {
    border-left: none;
  }

  .pipe-step::after {
    content: '→';
    position: absolute;
    right: -14px;
    top: 50%;
    transform: translateY(-50%);
    color: #60a5fa;
    font-size: 1.1rem;
    z-index: 2;
    background: var(--navy);
    padding: 0 2px;
  }

  .pipe-step:last-child::after {
    display: none;
  }

  .pipe-icon {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
  }

  .pipe-name {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: #60a5fa;
    margin-bottom: 0.4rem;
  }

  .pipe-desc {
    font-size: 0.78rem;
    color: #94a3b8;
    line-height: 1.4;
  }

  /* Tabs architecture */
  .tabs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
  }

  .tab-card {
    border-radius: 10px;
    padding: 1.25rem 1rem;
    border: 1px solid var(--border);
    background: var(--navy-light);
    transition: border-color 0.2s, background 0.2s;
  }

  .tab-card:hover {
    border-color: #3b82f6;
    background: rgb(37 99 235 / 0.08);
  }

  .tab-num {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    color: #475569;
    margin-bottom: 0.4rem;
  }

  .tab-name {
    font-weight: 600;
    color: #e2e8f0;
    font-size: 0.88rem;
    margin-bottom: 0.4rem;
  }

  .tab-desc {
    font-size: 0.78rem;
    color: #64748b;
    line-height: 1.5;
  }

  /* ── RESULTS ── */
  .results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
  }

  .result-card {
    border-radius: 12px;
    padding: 1.75rem 1.5rem;
    text-align: center;
    border: 1px solid var(--border);
    background: var(--navy-light);
    position: relative;
    overflow: hidden;
  }

  .result-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
  }

  .result-card.rc-green::before {
    background: linear-gradient(90deg, #16a34a, #4ade80);
  }

  .result-card.rc-blue::before {
    background: linear-gradient(90deg, #2563eb, #60a5fa);
  }

  .result-card.rc-red::before {
    background: linear-gradient(90deg, #dc2626, #f87171);
  }

  .result-card.rc-purple::before {
    background: linear-gradient(90deg, #7c3aed, #a78bfa);
  }

  .result-card.rc-amber::before {
    background: linear-gradient(90deg, #d97706, #fcd34d);
  }

  .result-val {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 900;
    line-height: 1;
    margin-bottom: 0.4rem;
  }

  .rc-green .result-val {
    color: #4ade80;
  }

  .rc-blue .result-val {
    color: #60a5fa;
  }

  .rc-red .result-val {
    color: #f87171;
  }

  .rc-purple .result-val {
    color: #a78bfa;
  }

  .rc-amber .result-val {
    color: #fcd34d;
  }

  .result-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: #64748b;
  }

  .result-context {
    font-size: 0.78rem;
    color: #475569;
    margin-top: 0.3rem;
  }

  /* SHAP bars */
  .shap-chart {
    background: var(--navy-light);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 3rem;
  }

  .shap-title {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: #60a5fa;
    margin-bottom: 1.5rem;
  }

  .shap-row {
    display: grid;
    grid-template-columns: 180px 1fr 60px;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
  }

  @media (width <= 520px) {
    .shap-row {
      grid-template-columns: 1fr;
      gap: 0.3rem;
    }
  }

  .shap-feature {
    font-size: 0.82rem;
    color: #cbd5e1;
    text-align: right;
  }

  @media (width <= 520px) {
    .shap-feature {
      text-align: left;
    }
  }

  .shap-bar-wrap {
    height: 22px;
    background: rgb(255 255 255 / 0.05);
    border-radius: 4px;
    overflow: hidden;
  }

  .shap-bar {
    height: 100%;
    border-radius: 4px;
    background: linear-gradient(90deg, #dc2626, #f97316);
    width: 0%;
    transition: width 1.2s cubic-bezier(0.22, 0.61, 0.36, 1);
  }

  .shap-val {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: #fca5a5;
    text-align: right;
  }

  /* ── IMPACT ── */
  .impact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
  }

  .impact-card {
    border-radius: 12px;
    padding: 1.5rem;
    background: var(--white);
    border: 1px solid var(--border-light);
    box-shadow: 0 1px 3px rgb(0 0 0 / 0.05);
    transition: transform 0.2s, box-shadow 0.2s;
  }

  .impact-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 28px rgb(0 0 0 / 0.08);
  }

  .impact-icon {
    font-size: 2rem;
    margin-bottom: 0.75rem;
  }

  .impact-title {
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--ink);
    margin-bottom: 0.4rem;
  }

  .impact-desc {
    font-size: 0.85rem;
    color: var(--slate);
    line-height: 1.6;
  }

  .stakeholder-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
  }

  .stake-card {
    border-radius: 10px;
    padding: 1.25rem;
    border-left: 3px solid;
  }

  .stake-card.pathologist {
    border-color: var(--blue);
    background: var(--blue-light);
  }

  .stake-card.institution {
    border-color: var(--green);
    background: var(--green-light);
  }

  .stake-card.researcher {
    border-color: var(--purple);
    background: #fdf4ff;
  }

  .stake-card.practitioner {
    border-color: var(--amber);
    background: var(--amber-light);
  }

  .stake-name {
    font-weight: 700;
    font-size: 0.88rem;
    margin-bottom: 0.5rem;
    color: var(--ink);
  }

  .stake-items {
    list-style: none;
  }

  .stake-items li {
    font-size: 0.82rem;
    color: var(--slate);
    padding: 0.2rem 0;
    display: flex;
    align-items: flex-start;
    gap: 0.4rem;
  }

  .stake-items li::before {
    content: '→';
    flex-shrink: 0;
  }

  /* ── ETHICS ── */
  .ethics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1rem;
    margin-bottom: 3rem;
  }

  .ethics-card {
    border-radius: 12px;
    padding: 1.5rem;
    background: var(--navy-light);
    border: 1px solid var(--border);
  }

  .ethics-icon {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
  }

  .ethics-title {
    font-weight: 700;
    font-size: 0.88rem;
    color: #e2e8f0;
    margin-bottom: 0.5rem;
  }

  .ethics-desc {
    font-size: 0.82rem;
    color: #94a3b8;
    line-height: 1.6;
  }

  /* ── LESSONS ── */
  .lessons-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
  }

  .lesson-item {
    display: grid;
    grid-template-columns: 60px 1fr;
    gap: 1.5rem;
    align-items: start;
    padding: 1.5rem;
    background: var(--white);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    box-shadow: 0 1px 3px rgb(0 0 0 / 0.04);
    transition: transform 0.2s;
  }

  .lesson-item:hover {
    transform: translateX(4px);
  }

  .lesson-num {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 900;
    color: var(--border-light);
    line-height: 1;
    text-align: center;
    padding-top: 0.25rem;
  }

  .lesson-title {
    font-weight: 700;
    font-size: 1rem;
    color: var(--ink);
    margin-bottom: 0.4rem;
  }

  .lesson-desc {
    font-size: 0.88rem;
    color: var(--slate);
    line-height: 1.7;
  }

  /* ── FUTURE ── */

  /* ── TECH STACK ── */
  .tech-row {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 2rem;
  }

  .tech-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--navy-light);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: #e2e8f0;
    font-weight: 500;
    transition: border-color 0.2s;
  }

  .tech-badge:hover {
    border-color: #60a5fa;
  }

  .tech-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #60a5fa;
    flex-shrink: 0;
  }

  .tech-dot.green {
    background: #4ade80;
  }

  .tech-dot.amber {
    background: #fcd34d;
  }

  .tech-dot.red {
    background: #f87171;
  }

  .tech-dot.purple {
    background: #a78bfa;
  }


  /* ── SCROLL REVEAL ── */
  .reveal {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.7s ease, transform 0.7s ease;
  }

  .reveal.visible {
    opacity: 1;
    transform: translateY(0);
  }

  .reveal-delay-1 {
    transition-delay: 0.1s;
  }

  .reveal-delay-2 {
    transition-delay: 0.2s;
  }

  .reveal-delay-3 {
    transition-delay: 0.3s;
  }

  .reveal-delay-4 {
    transition-delay: 0.4s;
  }

  /* ── DIVIDER ── */
  .divider {
    height: 1px;
    background: var(--border-light);
    max-width: 1100px;
    margin: 0 auto;
  }

  .divider-dark {
    background: var(--border);
  }

  /* ── CALLOUT ── */
  .callout {
    border-left: 3px solid var(--blue);
    background: var(--blue-light);
    border-radius: 0 10px 10px 0;
    padding: 1.25rem 1.5rem;
    margin: 2rem 0;
  }

  .callout p {
    font-style: italic;
    color: var(--slate);
    font-size: 0.95rem;
    line-height: 1.7;
  }

  .callout p strong {
    color: var(--ink);
    font-style: normal;
  }

  /* ── SECTION DIVIDER SHAPE ── */
  .shape-divider {
    width: 100%;
    overflow: hidden;
    line-height: 0;
    background: var(--off-white);
  }

  .shape-divider svg {
    display: block;
  }

  /* Impact comparison table */
  .impact-table {
    width: 100%;
    border-collapse: collapse;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 1px 3px rgb(0 0 0 / 0.06);
    margin-bottom: 2rem;
  }

  .impact-table thead {
    background: var(--navy);
    color: var(--white);
  }

  .impact-table th {
    padding: 1rem 1.25rem;
    text-align: left;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
  }


  /* ── TABLES (Ordered by specificity to satisfy Stylelint) ── */
  .comparison-table,
  .future-table,
  .impact-table {
    width: 100%;
    border-collapse: collapse;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 1px 3px rgb(0 0 0 / 0.06);
  }

  .comparison-table thead,
  .future-table thead,
  .impact-table thead {
    background: var(--navy);
    color: var(--white);
  }

  .comparison-table th,
  .future-table th,
  .impact-table th {
    padding: 1rem 1.25rem;
    text-align: left;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    font-weight: 500;
  }

  .comparison-table td,
  .future-table td,
  .impact-table td {
    padding: 0.9rem 1.25rem;
    border-bottom: 1px solid var(--border-light);
    vertical-align: middle;
  }

  .comparison-table { font-size: 0.9rem; }
  .future-table td, .impact-table td { font-size: 0.88rem; }

  .comparison-table tbody tr:nth-child(even),
  .future-table tbody tr:nth-child(even),
  .impact-table tbody tr:nth-child(even) {
    background: #f8fafc;
  }

  .comparison-table .td-pain,
  .comparison-table .td-legacy,
  .comparison-table .td-new,
  .impact-table .td-baseline,
  .impact-table .td-system {
    font-size: 0.85rem;
  }

  .comparison-table .td-pain,
  .future-table td:first-child,
  .impact-table td:first-child {
    font-weight: 600;
    color: var(--ink);
  }

  .comparison-table .td-legacy,
  .impact-table .td-baseline {
    color: var(--red);
  }

  .comparison-table .td-new,
  .impact-table .td-system {
    color: var(--green);
    font-weight: 500;
  }

  .future-table td:last-child {
    color: var(--slate);
  }

  .comparison-table tbody tr:last-child td,
  .future-table tbody tr:last-child td,
  .impact-table tbody tr:last-child td {
    border-bottom: none;
  }

  /* ── FOOTER OVERRIDES FOR DARK BG ── */
  .site-footer .social-link11 {
    color: #e2e8f0;
    border-color: rgb(255 255 255 / 0.1);
    background: rgb(255 255 255 / 0.05);
  }

  .site-footer .social-link11:hover {
    color: var(--blue);
    border-color: var(--blue);
    background: rgb(37 99 235 / 0.1);
  }

  .site-footer .back-to-top {
    color: #e2e8f0;
    border-color: rgb(255 255 255 / 0.1);
    background: rgb(255 255 255 / 0.05);
  }

  .site-footer .copyright,
  .site-footer .made-with {
    color: #94a3b8;
  }

  /* ── STICKY GITHUB BUTTON ── */
  .sticky-repo-btn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 999;
    background: linear-gradient(135deg, #2563eb, #7c3aed);
    color: white;
    text-decoration: none;
    padding: 12px 24px;
    border-radius: 50px;
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: 0 10px 25px rgb(124 58 237 / 0.3);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    border: 1px solid rgb(255 255 255 / 0.1);
  }

  .sticky-repo-btn:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 15px 35px rgb(124 58 237 / 0.4);
    filter: brightness(1.1);
  }

  .sticky-repo-btn i {
    font-size: 1.2rem;
  }

  @media (width <= 768px) {
    .sticky-repo-btn {
      bottom: 20px;
      right: 20px;
      padding: 10px 20px;
      font-size: 0.85rem;
    }
  }