:root{
    --bg:#10141b;
    --panel:#171d27;
    --panel-2:#1e2634;
    --line:#2a3444;
    --text:#e6eaf2;
    --muted:#8b96a8;
    --faint:#5b6578;
    --v1:#e8a33d;   /* 1983 · phosphor amber */
    --v2:#53c7b8;   /* 2002 · improved teal  */
    --v1-dim:rgba(232,163,61,.14);
    --v2-dim:rgba(83,199,184,.14);
    --radius:14px;
    --mono:'IBM Plex Mono',ui-monospace,monospace;
    --body:'Instrument Sans',system-ui,sans-serif;
    --display:'Bricolage Grotesque','Instrument Sans',sans-serif;
  }
  *{box-sizing:border-box;margin:0;padding:0}
  html{scroll-behavior:smooth}
  body{background:var(--bg);color:var(--text);font-family:var(--body);line-height:1.6;-webkit-font-smoothing:antialiased}
  ::selection{background:rgba(83,199,184,.35)}

  .wrap{max-width:1060px;margin:0 auto;padding:0 20px}

  /* ---------- hero ---------- */
  .hero{position:relative;height:min(78vh,640px);min-height:460px;overflow:hidden;border-bottom:1px solid var(--line)}
  .hero canvas{position:absolute;inset:0;width:100%;height:100%;display:block;filter:saturate(0)}
  .hero::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(16,20,27,.25) 0%,rgba(16,20,27,.55) 55%,rgba(16,20,27,.92) 100%);pointer-events:none}
  .hero-divider{position:absolute;top:0;bottom:0;width:34px;margin-left:-17px;cursor:ew-resize;z-index:4;touch-action:none}
  .hero-divider::before{content:"";position:absolute;top:0;bottom:0;left:50%;width:2px;margin-left:-1px;background:linear-gradient(180deg,var(--v1),var(--v2))}
  .hero-divider .grip{position:absolute;top:38%;left:50%;transform:translate(-50%,-50%);width:30px;height:30px;border-radius:50%;background:var(--bg);border:2px solid var(--line);display:flex;align-items:center;justify-content:center;font-family:var(--mono);font-size:11px;color:var(--muted);box-shadow:0 2px 14px rgba(0,0,0,.5)}
  .hero-tag{position:absolute;top:18px;z-index:3;font-family:var(--mono);font-size:11px;letter-spacing:.08em;padding:5px 10px;border-radius:999px;background:rgba(16,20,27,.72);backdrop-filter:blur(4px)}
  .tag-v1{left:18px;color:var(--v1);border:1px solid rgba(232,163,61,.4)}
  .tag-v2{right:18px;color:var(--v2);border:1px solid rgba(83,199,184,.4)}
  .hero-content{position:absolute;left:0;right:0;bottom:0;z-index:3;padding:28px 20px 34px}
  .hero-inner{max-width:1060px;margin:0 auto}
  .eyebrow{font-family:var(--mono);font-size:12px;letter-spacing:.18em;text-transform:uppercase;color:var(--muted)}
  .hero h1{font-family:var(--display);font-weight:800;font-size:clamp(34px,6.4vw,64px);line-height:1.02;letter-spacing:-.01em;margin:10px 0 12px}
  .hero h1 .y1{color:var(--v1)}
  .hero h1 .y2{color:var(--v2)}
  .hero p.lede{max-width:560px;color:#c4ccda;font-size:clamp(14px,1.8vw,16px)}
  .hero-legend{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px;align-items:center}
  .chip{display:inline-flex;align-items:center;gap:7px;font-family:var(--mono);font-size:11px;color:var(--muted);background:rgba(23,29,39,.8);border:1px solid var(--line);border-radius:999px;padding:5px 11px}
  .chip .dot{width:8px;height:8px;border-radius:50%}
  .dot-v1{background:var(--v1)} .dot-v2{background:var(--v2)}
  .btn-ghost{font-family:var(--mono);font-size:11px;color:var(--text);background:transparent;border:1px solid var(--line);border-radius:999px;padding:5px 12px;cursor:pointer}
  .btn-ghost:hover{border-color:var(--muted)}

  /* ---------- sections ---------- */
  section{padding:64px 0 8px}
  .sec-head{margin-bottom:26px}
  .sec-head .eyebrow{display:block;margin-bottom:8px}
  .sec-head h2{font-family:var(--display);font-weight:700;font-size:clamp(24px,3.6vw,34px);letter-spacing:-.01em}
  .sec-head p{color:var(--muted);max-width:640px;margin-top:8px;font-size:15px}

  /* ---------- pipeline ---------- */
  .steps{display:flex;flex-direction:column;gap:14px}
  .step{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:20px 22px;display:grid;grid-template-columns:64px 1fr auto;gap:18px;align-items:start}
  .step-num{font-family:var(--mono);font-size:12px;color:var(--muted);padding-top:3px}
  .step-num b{display:block;font-size:22px;color:var(--text);font-weight:600}
  .step h3{font-family:var(--display);font-weight:600;font-size:18px;margin-bottom:10px}
  .delta{display:flex;flex-direction:column;gap:8px}
  .vrow{display:grid;grid-template-columns:52px 1fr;gap:10px;align-items:baseline;font-size:14px}
  .vrow .yr{font-family:var(--mono);font-size:11px;letter-spacing:.06em;padding:2px 0;text-align:center;border-radius:6px}
  .yr-1{color:var(--v1);background:var(--v1-dim)}
  .yr-2{color:var(--v2);background:var(--v2-dim)}
  .yr-b{color:var(--muted);background:rgba(139,150,168,.12)}
  .vrow p{color:#c4ccda}
  .vrow code{font-family:var(--mono);font-size:12.5px;color:var(--text);background:var(--panel-2);border:1px solid var(--line);border-radius:6px;padding:1px 6px;white-space:nowrap}
  .step-chip{font-family:var(--mono);font-size:11px;letter-spacing:.05em;color:var(--text);border:1px solid var(--line);background:var(--panel-2);border-radius:999px;padding:4px 11px;white-space:nowrap;justify-self:end}
  .step-chip.same{color:var(--muted)}
  .step-chip.changed{border-color:rgba(83,199,184,.45);color:var(--v2)}

  /* ---------- labs ---------- */
  .lab{background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:24px;margin-top:8px}
  .lab-grid{display:grid;grid-template-columns:minmax(260px,340px) 1fr;gap:26px;align-items:start}
  .controls{display:flex;flex-direction:column;gap:18px}
  .ctl-label{font-family:var(--mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);margin-bottom:8px;display:block}
  .seg{display:flex;flex-direction:column;gap:6px}
  .seg button{text-align:left;font-family:var(--body);font-size:14px;color:#c4ccda;background:var(--panel-2);border:1px solid var(--line);border-radius:10px;padding:9px 12px;cursor:pointer;transition:border-color .15s,background .15s}
  .seg button .k{font-family:var(--mono);font-size:11px;color:var(--muted);display:block;margin-top:1px}
  .seg button:hover{border-color:var(--muted)}
  .seg button.on{border-color:var(--v2);background:var(--v2-dim);color:var(--text)}
  .seg button.on.tone-v1{border-color:var(--v1);background:var(--v1-dim)}
  .seg button.on.tone-plain{border-color:var(--muted);background:rgba(139,150,168,.12)}
  .canvas-card{background:var(--panel-2);border:1px solid var(--line);border-radius:14px;padding:12px}
  .canvas-card canvas{display:block;width:100%;border-radius:8px}
  .canvas-cap{font-family:var(--mono);font-size:11px;color:var(--muted);margin-top:10px;line-height:1.6}
  .note{border-left:3px solid var(--line);padding:2px 0 2px 14px;color:var(--muted);font-size:13.5px}
  .note b{color:var(--text);font-weight:600}
  .badges{display:flex;gap:6px;flex-wrap:wrap;margin-top:10px}
  .badge{font-family:var(--mono);font-size:11px;border-radius:6px;padding:3px 8px;border:1px solid var(--line);color:var(--muted)}
  .badge.ok{color:var(--v2);border-color:rgba(83,199,184,.45)}
  .badge.bad{color:var(--v1);border-color:rgba(232,163,61,.45)}
  input[type=range]{width:100%;accent-color:var(--v2);background:transparent}
  .slider-row{display:flex;align-items:center;gap:12px}
  .slider-row .val{font-family:var(--mono);font-size:13px;color:var(--text);min-width:44px;text-align:right}

  footer{margin-top:80px;border-top:1px solid var(--line);padding:34px 0 54px}
  footer p{color:var(--muted);font-size:13.5px;max-width:680px}
  footer a{color:var(--v2);text-decoration:none;border-bottom:1px solid rgba(83,199,184,.35)}
  footer a:hover{border-bottom-color:var(--v2)}
  footer .src{margin-top:10px}

  @media (max-width:820px){
    .lab-grid{grid-template-columns:1fr}
    .step{grid-template-columns:1fr;gap:10px}
    .step-chip{justify-self:start}
    .step-num b{display:inline;margin-right:8px}
  }
  @media (prefers-reduced-motion:reduce){
    html{scroll-behavior:auto}
  }