:root {
    --ink: #0f1e1b;
    --ink-soft: #3a5750;
    --ink-faint: #6a8880;
    --paper: #eef6f1;
    --paper-raised: #ffffff;
    --paper-sunk: #dcf0e6;
    --line: #b9d8c9;
    --accent: #ff5f2e;
    --accent-soft: #ffe1d0;
    --teal: #0e9a86;
    --teal-soft: #c9f1e7;
    --violet: #7c4dff;
    --violet-soft: #e9e1ff;
    --danger: #e0303f;
    --danger-soft: #fcd8db;
    --good: #12a563;
    --glare: rgba(255, 255, 255, 0.65);
    --particle: 14, 154, 134;
    --shadow-card: 0 1px 2px rgba(15, 30, 27, .04), 0 8px 20px -12px rgba(15, 30, 27, .12);
    color-scheme: light;
  }
  :root:not([data-theme="light"]) {
    @media (prefers-color-scheme: dark) {
      --ink: #eef8f3; --ink-soft: #a9c7bb; --ink-faint: #7ea394;
      --paper: #0a1613; --paper-raised: #142623; --paper-sunk: #0d1c19;
      --line: #24473c; --accent: #ff8a5c; --accent-soft: #3d281a;
      --teal: #35cbb2; --teal-soft: #123a34; --violet: #a98bff; --violet-soft: #26204a;
      --danger: #ff6b6f; --danger-soft: #3a1c1e; --good: #4fdb96;
      --glare: rgba(255, 255, 255, 0.1); --particle: 53, 203, 178;
      --shadow-card: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px -12px rgba(0, 0, 0, .5);
      color-scheme: dark;
    }
  }
  :root[data-theme="dark"] {
    --ink: #eef8f3; --ink-soft: #a9c7bb; --ink-faint: #7ea394;
    --paper: #0a1613; --paper-raised: #142623; --paper-sunk: #0d1c19;
    --line: #24473c; --accent: #ff8a5c; --accent-soft: #3d281a;
    --teal: #35cbb2; --teal-soft: #123a34; --violet: #a98bff; --violet-soft: #26204a;
    --danger: #ff6b6f; --danger-soft: #3a1c1e; --good: #4fdb96;
    --glare: rgba(255, 255, 255, 0.1); --particle: 53, 203, 178;
    --shadow-card: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px -12px rgba(0, 0, 0, .5);
    color-scheme: dark;
  }

  * { box-sizing: border-box; }
  html, body { margin: 0; padding: 0; background: var(--paper); color: var(--ink); }
  body {
    font-family: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    font-size: 15.5px; line-height: 1.55; -webkit-font-smoothing: antialiased;
  }
  ::selection { background: var(--accent-soft); color: var(--ink); }
  a { color: inherit; }
  .display { font-family: "Instrument Serif", Georgia, serif; font-weight: 400; letter-spacing: -0.01em; text-wrap: balance; }
  .mono { font-family: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace; }
  .eyebrow { font-family: "IBM Plex Mono", monospace; font-size: .7rem; letter-spacing: .1em; text-transform: uppercase; color: var(--accent); font-weight: 500; }
  h1, h2, h3, h4 { margin: 0; }
  p { margin: 0; }
  button { font-family: inherit; }

  /* ---------- shell layout ---------- */
  .shell { display: flex; min-height: 100vh; }
  .sidebar {
    flex: 0 0 240px;
    border-right: 1px solid var(--line);
    padding: 22px 16px;
    position: sticky; top: 0; height: 100vh; overflow-y: auto;
  }
  .sidebar-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 10px; }
  .wordmark { font-family: "Instrument Serif", serif; font-size: 1.3rem; padding: 0 8px 4px; }
  .wordmark em { color: var(--accent); font-style: normal; }
  .subtag { font-family: "IBM Plex Mono", monospace; font-size: .68rem; color: var(--ink-soft); padding: 0 8px 18px; }

  /* mobile nav toggle, hidden on desktop */
  .navToggle {
    display: none; align-items: center; gap: 10px;
    background: var(--paper-raised); border: 1px solid var(--line); border-radius: 6px;
    padding: 9px 12px; cursor: pointer; color: var(--ink);
  }
  .navToggle-label {
    font-size: .72rem; color: var(--ink-soft);
    max-width: 118px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  }
  .navToggle-icon { display: flex; flex-direction: column; gap: 3px; width: 16px; }
  .navToggle-icon i { display: block; height: 2px; background: var(--ink); border-radius: 1px; transition: transform .2s ease, opacity .2s ease; }
  .navToggle[aria-expanded="true"] .navToggle-icon i:nth-child(1) { transform: translateY(5px) rotate(45deg); }
  .navToggle[aria-expanded="true"] .navToggle-icon i:nth-child(2) { opacity: 0; }
  .navToggle[aria-expanded="true"] .navToggle-icon i:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

  .navlist { display: flex; flex-direction: column; gap: 3px; margin-top: 8px; }
  .navbtn {
    display: flex; align-items: center; gap: 10px; width: 100%; text-align: left;
    background: transparent; border: none; cursor: pointer;
    padding: 10px 10px; border-radius: 5px;
    font-size: .86rem; color: var(--ink-soft);
    border-left: 3px solid transparent;
  }
  .navbtn .nn {
    font-family: "IBM Plex Mono", monospace; font-size: .68rem; font-weight: 600;
    color: var(--ink-faint); flex: 0 0 auto;
    width: 22px; height: 22px; border-radius: 5px;
    display: flex; align-items: center; justify-content: center;
    background: var(--paper-sunk);
  }
  .navbtn:hover { background: var(--paper-raised); color: var(--ink); }
  .navbtn.active { background: var(--paper-raised); color: var(--ink); font-weight: 600; box-shadow: var(--shadow-card); }
  .navbtn:nth-child(3n+1) .nn { color: var(--accent); background: var(--accent-soft); }
  .navbtn:nth-child(3n+2) .nn { color: var(--teal); background: var(--teal-soft); }
  .navbtn:nth-child(3n+3) .nn { color: var(--violet); background: var(--violet-soft); }
  .navbtn:nth-child(3n+1).active { border-left-color: var(--accent); }
  .navbtn:nth-child(3n+2).active { border-left-color: var(--teal); }
  .navbtn:nth-child(3n+3).active { border-left-color: var(--violet); }

  .dataset-box {
    margin-top: 22px; padding: 12px 12px 14px; border: 1px solid var(--line); background: var(--paper-raised);
  }
  .dataset-box .dlabel { font-family: "IBM Plex Mono", monospace; font-size: .64rem; color: var(--ink-soft); text-transform: uppercase; letter-spacing: .06em; }
  .dataset-box .dval { font-family: "IBM Plex Mono", monospace; font-size: 1.1rem; margin: 4px 0 10px; }
  .dataset-box.market-box { margin-top: 10px; }
  .dataset-box.market-box select { width: 100%; margin: 6px 0 8px; font-size: .76rem; padding: 7px 9px; }
  .dataset-box.market-box .market-note { font-size: .68rem; line-height: 1.5; color: var(--ink-faint); margin: 0; }
  .btn {
    display: inline-flex; align-items: center; gap: 6px;
    font-family: "IBM Plex Mono", monospace; font-size: .74rem;
    padding: 8px 12px; border: 1px solid var(--ink); background: var(--ink); color: var(--paper);
    cursor: pointer; border-radius: 2px; width: 100%; justify-content: center;
  }
  .btn:hover { background: var(--accent); border-color: var(--accent); }
  .btn.ghost { background: transparent; color: var(--ink); border-color: var(--line); }
  .btn.ghost:hover { border-color: var(--accent); color: var(--accent); background: transparent; }
  .btn:disabled { opacity: .5; cursor: not-allowed; }

  .main { flex: 1 1 auto; min-width: 0; padding: 40px 56px 100px; max-width: 1360px; }
  .tabpanel { display: none; }
  .tabpanel.active { display: block; }

  .head { margin-bottom: 28px; }
  .head h2 { font-size: clamp(1.6rem, 3vw, 2.1rem); margin: 8px 0 10px; }
  .head p.lede { color: var(--ink-soft); max-width: 780px; font-size: 1rem; line-height: 1.65; }

  /* ---------- explain panel ---------- */
  details.explain {
    border: 1px solid var(--line); background: var(--paper-raised);
    margin: 18px 0 28px; padding: 0;
  }
  details.explain summary {
    cursor: pointer; list-style: none; padding: 12px 16px;
    font-family: "IBM Plex Mono", monospace; font-size: .74rem; letter-spacing: .04em;
    color: var(--teal); display: flex; align-items: center; gap: 8px;
  }
  details.explain summary::-webkit-details-marker { display: none; }
  details.explain summary::before { content: "▸"; transition: transform .15s ease; }
  details.explain[open] summary::before { transform: rotate(90deg); }
  details.explain .exbody { padding: 4px 18px 18px; color: var(--ink-soft); font-size: .9rem; }
  details.explain .exbody p { margin: 0 0 10px; }
  details.explain .exbody p:last-child { margin-bottom: 0; }
  details.explain .exbody code { font-family: "IBM Plex Mono", monospace; font-size: .85em; background: var(--paper-sunk); padding: 1px 5px; color: var(--ink); }

  /* ---------- card / grid ---------- */
  .card { border: 1px solid var(--line); background: var(--paper-raised); padding: 20px 22px; border-radius: 10px; box-shadow: var(--shadow-card); }
  .grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
  .grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
  @media (max-width: 760px) { .grid2, .grid3 { grid-template-columns: 1fr; } }

  .stat { border: 1px solid var(--line); border-radius: 8px; padding: 12px 14px; background: var(--paper-sunk); }
  .stat .slabel { font-family: "IBM Plex Mono", monospace; font-size: .64rem; color: var(--ink-soft); text-transform: uppercase; letter-spacing: .05em; }
  .stat .sval { font-family: "IBM Plex Mono", monospace; font-size: 1.4rem; margin-top: 4px; font-variant-numeric: tabular-nums; font-weight: 600; }
  .stat .sval.up { color: var(--good); }
  .stat .sval.down { color: var(--danger); }

  table.dt { border-collapse: collapse; width: 100%; font-size: .84rem; }
  table.dt th, table.dt td { padding: 10px 12px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: middle; }
  table.dt th { font-family: "IBM Plex Mono", monospace; font-size: .66rem; text-transform: uppercase; letter-spacing: .05em; color: var(--ink-soft); background: var(--paper-sunk); }
  .tablewrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 10px; background: var(--paper-raised); box-shadow: var(--shadow-card); }
  .tablewrap table.dt { min-width: 620px; }

  .pill { font-family: "IBM Plex Mono", monospace; font-size: .64rem; font-weight: 600; padding: 3px 9px; border-radius: 20px; white-space: nowrap; }
  .pill.risk { background: var(--danger-soft); color: var(--danger); }
  .pill.vip { background: var(--teal-soft); color: var(--teal); }
  .pill.ok { background: var(--teal-soft); color: var(--good); }
  .pill.rg { background: var(--accent-soft); color: var(--accent); }
  .pill.new { background: var(--violet-soft); color: var(--violet); }
  .pill.muted { background: var(--paper-sunk); color: var(--ink-soft); }

  /* sparkline / bar chart */
  .bars { display: flex; align-items: flex-end; gap: 3px; height: 60px; }
  .bars i { flex: 1; background: var(--teal); opacity: .8; min-width: 2px; }

  /* funnel */
  .funnel { display: flex; flex-direction: column; gap: 8px; }
  .frow { display: grid; grid-template-columns: 160px 1fr 70px; align-items: center; gap: 10px; }
  .frow .flabel { font-size: .82rem; }
  .ftrack { height: 16px; border-radius: 5px; background: var(--paper-sunk); position: relative; overflow: hidden; }
  .ffill { height: 100%; border-radius: 5px; background: linear-gradient(90deg, var(--teal), color-mix(in srgb, var(--teal) 60%, var(--violet))); }
  .frow .fval { font-family: "IBM Plex Mono", monospace; font-size: .78rem; text-align: right; font-weight: 600; }
  @media (max-width: 560px) {
    .frow { grid-template-columns: 1fr; gap: 4px; }
    .frow .fval { text-align: left; }
  }

  /* heatmap */
  .heat-cell { font-family: "IBM Plex Mono", monospace; font-size: .74rem; font-weight: 600; text-align: center; padding: 6px 4px !important; color: var(--ink); border-radius: 4px; }

  /* slider */
  .sliderow { margin-bottom: 18px; }
  .sliderow .slabel-row { display: flex; justify-content: space-between; font-size: .82rem; margin-bottom: 6px; }
  .sliderow .slabel-row .sval { font-family: "IBM Plex Mono", monospace; color: var(--teal); font-weight: 600; }
  input[type="range"] { width: 100%; accent-color: var(--accent); height: 22px; }

  .badge-tier {
    display: inline-block; font-family: "IBM Plex Mono", monospace; font-size: .95rem; font-weight: 600;
    padding: 7px 16px; border-radius: 20px; border: 1px solid var(--accent); color: var(--accent); background: var(--accent-soft);
  }

  select, .templ-box {
    font-family: "IBM Plex Mono", monospace; font-size: .82rem;
    background: var(--paper); color: var(--ink); border: 1px solid var(--line); border-radius: 7px; padding: 9px 11px;
  }
  select { width: 100%; margin-bottom: 14px; }
  .templ-box { white-space: pre-wrap; padding: 18px; line-height: 1.7; }
  .templ-box .fill { color: var(--teal); font-weight: 600; }

  .weight-row { display: grid; grid-template-columns: 140px 1fr 60px; align-items: center; gap: 10px; margin-bottom: 6px; font-size: .82rem; }
  .weight-track { height: 8px; border-radius: 4px; background: var(--paper-sunk); position: relative; overflow: hidden; }
  .weight-fill { height: 100%; }
  .weight-fill.pos { background: var(--teal); }
  .weight-fill.neg { background: var(--danger); }
  @media (max-width: 560px) { .weight-row { grid-template-columns: 100px 1fr 50px; font-size: .76rem; } }

  footer.page { border-top: 1px solid var(--line); margin-top: 60px; padding-top: 24px; font-size: .8rem; color: var(--ink-soft); }
  footer.page a { text-decoration: underline; text-decoration-color: var(--line); text-underline-offset: 3px; }
  footer.page a:hover { color: var(--accent); text-decoration-color: var(--accent); }

  @media (max-width: 900px) {
    .shell { flex-direction: column; }
    .sidebar {
      position: sticky; top: 0; z-index: 20; height: auto; flex: none; width: 100%;
      border-right: none; border-bottom: 1px solid var(--line);
      background: var(--paper); padding: 14px 16px;
    }
    .sidebar-top { align-items: center; }
    .wordmark { font-size: 1.15rem; padding: 0 0 2px; }
    .subtag { padding: 0 0 0; }
    .navToggle { display: flex; }

    .navlist {
      flex-direction: column; gap: 3px;
      max-height: 0; overflow: hidden; margin-top: 0;
      transition: max-height .3s ease, margin-top .3s ease;
    }
    .navlist.open { max-height: min(70vh, 640px); overflow-y: auto; margin-top: 14px; }
    .navbtn { white-space: normal; }

    .dataset-box {
      margin-top: 12px; padding: 8px 12px;
      display: flex; align-items: center; justify-content: space-between; gap: 10px;
    }
    .dataset-box .dlabel { display: none; }
    .dataset-box .dval { font-size: .82rem; margin: 0; white-space: nowrap; }
    .dataset-box .btn { width: auto; padding: 7px 12px; font-size: .68rem; }

    .dataset-box.market-box {
      display: block; margin-top: 8px; padding: 10px 12px;
    }
    .dataset-box.market-box .dlabel { display: block; }

    .main { padding: 24px 18px 70px; }
  }

  @media (max-width: 520px) {
    body { font-size: 14.5px; }
    .head h2 { font-size: 1.5rem; }
    .head p.lede { font-size: .9rem; }
    .card { padding: 16px; }
    .stat .sval { font-size: 1.15rem; }
    table.dt th, table.dt td { padding: 8px 8px; font-size: .78rem; }
    .btn { font-size: .7rem; padding: 10px 12px; }
    .eyebrow { font-size: .65rem; }
  }

  a:focus-visible, button:focus-visible, select:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

  /* ---------- ambient particle field ---------- */
  #magnetCanvas {
    position: fixed; inset: 0; width: 100%; height: 100%;
    pointer-events: none; z-index: 0; display: block;
  }
  .shell { position: relative; z-index: 1; }

  /* ---------- magnetic cursor dot ---------- */
  #cursorDot {
    position: fixed; top: 0; left: 0; width: 16px; height: 16px; margin: -8px 0 0 -8px;
    border-radius: 50%; border: 1.5px solid var(--accent); background: transparent;
    pointer-events: none; z-index: 9999; opacity: 0; transition: opacity .25s ease, width .2s ease, height .2s ease, margin .2s ease, background .2s ease;
    will-change: transform;
  }
  #cursorDot.live { opacity: .8; }
  #cursorDot.hovering { width: 34px; height: 34px; margin: -17px 0 0 -17px; background: var(--accent-soft); opacity: .55; }

  /* ---------- magnetic pull targets ---------- */
  .btn, .navbtn { transition: transform .35s cubic-bezier(.34, 1.56, .64, 1); will-change: transform; }

  /* ---------- 3d tilt (stat tiles) ---------- */
  .stat { transition: transform .25s ease, box-shadow .25s ease; transform-style: preserve-3d; will-change: transform; }
  .stat.tilting { transition: none; box-shadow: 0 14px 30px -12px rgba(0, 0, 0, .28); }

  /* ---------- cursor glare on cards ---------- */
  .card, .mockframe, details.explain {
    position: relative; overflow: hidden;
  }
  .card::before, details.explain::before {
    content: ""; position: absolute; inset: 0; pointer-events: none; z-index: 0;
    background: radial-gradient(320px circle at var(--mx, 50%) var(--my, 50%), var(--glare), transparent 65%);
    opacity: 0; transition: opacity .3s ease;
  }
  .card.glaring::before, details.explain.glaring::before { opacity: 1; }
  .card > *, details.explain > * { position: relative; z-index: 1; }

  /* ---------- rotating 3d mark ---------- */
  .cube-scene { width: 22px; height: 22px; perspective: 200px; display: inline-block; vertical-align: -5px; margin-right: 6px; }
  .cube {
    width: 100%; height: 100%; position: relative; transform-style: preserve-3d;
    animation: cube-spin 9s linear infinite;
  }
  .cube .face {
    position: absolute; width: 22px; height: 22px; border: 1px solid var(--accent);
    background: var(--accent-soft); opacity: .85;
  }
  .cube .f1 { transform: translateZ(11px); }
  .cube .f2 { transform: rotateY(90deg) translateZ(11px); }
  .cube .f3 { transform: rotateY(180deg) translateZ(11px); }
  .cube .f4 { transform: rotateY(-90deg) translateZ(11px); }
  .cube .f5 { transform: rotateX(90deg) translateZ(11px); }
  .cube .f6 { transform: rotateX(-90deg) translateZ(11px); }
  @keyframes cube-spin { from { transform: rotateX(-18deg) rotateY(0deg); } to { transform: rotateX(-18deg) rotateY(360deg); } }
  @media (prefers-reduced-motion: reduce) { .cube { animation: none; transform: rotateX(-18deg) rotateY(28deg); } }

  /* ---------- richer 3d bars ---------- */
  .bars i {
    background: linear-gradient(180deg, color-mix(in srgb, var(--teal) 85%, white 15%), var(--teal));
    box-shadow: 0 3px 8px -3px rgba(0, 0, 0, .35), inset 0 1px 0 rgba(255, 255, 255, .25);
    border-radius: 2px 2px 0 0;
    transition: transform .2s ease;
  }
  .bars:hover i:hover { transform: scaleY(1.04); }

  /* ---------- table row depth ---------- */
  table.dt tbody tr { transition: background .15s ease, box-shadow .15s ease, transform .15s ease; }
  table.dt tbody tr:hover { background: var(--paper-sunk); box-shadow: inset 3px 0 0 var(--accent); }

  /* ---------- scroll reveal ---------- */
  @media (prefers-reduced-motion: no-preference) {
    .reveal { opacity: 0; transform: translateY(14px); transition: opacity .55s ease, transform .55s ease; }
    .reveal.in { opacity: 1; transform: none; }
  }

  /* ---------- module 11: cohort chart ---------- */
  #cohortChart svg { display: block; }
  #cohortChart text { font-family: "IBM Plex Mono", monospace; }

  /* ---------- module 10 / 12: campaign brief document ---------- */
  .brief-doc { border: 1px solid var(--line); background: var(--paper-raised); border-radius: 10px; padding: 24px; box-shadow: var(--shadow-card); }
  .brief-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; flex-wrap: wrap; border-bottom: 1px solid var(--line); padding-bottom: 14px; }
  @media (max-width: 560px) { .brief-doc { padding: 16px; } .brief-head { flex-direction: column; } }

  /* ---------- print: campaign brief only ---------- */
  @media print {
    .sidebar, #magnetCanvas, #cursorDot, details.explain, .head, footer.page,
    #generateBriefBtn, #printBriefBtn, #briefSegment, .sliderow {
      display: none !important;
    }
    .main { padding: 0; max-width: none; }
    .tabpanel { display: none !important; }
    .tabpanel#panel-brief { display: block !important; }
    .brief-doc { box-shadow: none; border: 1px solid #999; }
    body { background: #fff; color: #000; }
  }

  /* ---------- impact band (Start Here) ---------- */
  .kpi-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 12px; margin-bottom: 14px; }
  .kpi { background: var(--paper-raised); border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; }
  .kpi .n { font-family: var(--font-display, Georgia, serif); font-size: 2.15rem; line-height: 1.05; color: var(--ink); }
  .kpi .n.accent { color: var(--accent); }
  .kpi .n.teal { color: var(--teal); }
  .kpi .l { font-size: .82rem; color: var(--ink-soft); margin-top: 4px; }
  .chart-card { background: var(--paper-raised); border: 1px solid var(--line); border-radius: 12px; padding: 18px 20px; }
  .chart-card h4 { font-size: .92rem; color: var(--ink); margin: 0 0 2px; font-weight: 600; }
  .chart-card .sub { font-size: .8rem; color: var(--ink-faint); margin-bottom: 12px; }
  .chart-duo { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 12px; margin-top: 12px; }
  .lgnd { display: flex; gap: 14px; font-size: .74rem; color: var(--ink-soft); margin-bottom: 8px; }
  .lgnd i { width: 9px; height: 9px; border-radius: 2px; display: inline-block; margin-right: 5px; }