The code, and where the rest lives.

// index.html — the engine answering you right now (verbatim)
function keyHits(nq, kl) {
  if (kl.includes(' ')) return nq.includes(kl);
  const k = kl.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
  return new RegExp('(^|\\s)' + k + (kl.length <= 4 ? 's?(\\s|$)' : '')).test(nq);
}
function retrieve(query) {
  const nq = norm(query);
  const qt = toks(query);
  let best = null, bestScore = 0, second = null, secondScore = 0;
  const scored = [];
  for (const e of KB) {
    // `not` keys veto an entry outright — this is what stops "case study"
    // scoring against the education entry via the word "study".
    if (e.not && e.not.some(n => nq.includes(n))) continue;
    let sc = 0;
    const used = new Set(); // a query word can score once per entry, however many keys share it
    for (const key of e.keys) {
      const kl = key.toLowerCase().trim();
      // A multi-word key is a much stronger signal than a single word,
      // so it outranks a generic one-word match on another entry.
      // Single words must start a word (so "tech" never matches "fintech"), and
      // short ones must be the whole word (so "ai" never matches "Aimee").
      if (kl.length >= 2 && keyHits(nq, kl)) { sc += 3 + (kl.split(' ').length - 1) * 2; continue; }
      for (const w of kl.split(' ')) {
        if (!w || STOP.has(w)) continue;
        const t = qt.find(t => fuzzy(t, w));
        if (t && !used.has(t)) { used.add(t); sc += 1; break; }
      }
    }
    if (sc > 0) scored.push({ e, sc });
    if (sc > bestScore) { second = best; secondScore = bestScore; best = e; bestScore = sc; }
    else if (sc > secondScore) { second = e; secondScore = sc; }
  }
  scored.sort((a, b) => b.sc - a.sc);
  return { entry: best, score: bestScore, second: secondScore >= 2 ? second : null, scored };
}