..a) => console.warn(%c[Match]%c ${m}, C, '', ...a); const err = (m, ...a) => console.error(%c[Match]%c ${m}, C, '', ...a); const sleep = ms => new Promise(r => setTimeout(r, ms)); const norm = s => (s || '').trim().toLowerCase().replace(/\s+/g, ' ');

const realClick = (el) => { const r = el.getBoundingClientRect(); const o = { bubbles: true, cancelable: true, view: window, clientX: r.left + r.width/2, clientY: r.top + r.height/2 }; el.dispatchEvent(new PointerEvent('pointerdown', { ...o, pointerType: 'mouse' })); el.dispatchEvent(new MouseEvent('mousedown', o)); el.dispatchEvent(new PointerEvent('pointerup', { ...o, pointerType: 'mouse' })); el.dispatchEvent(new MouseEvent('mouseup', o)); el.dispatchEvent(new MouseEvent('click', o)); };

const isVisible = (el) => { if (!el?.isConnected) return false; const r = el.getBoundingClientRect(); if (r.width < 1 || r.height < 1) return false; const cs = getComputedStyle(el); return cs.visibility !== 'hidden' && cs.display !== 'none' && parseFloat(cs.opacity) > 0.1; };

// 1. extract set id const m = location.pathname.match(/^/(?:[a-z]{2}/)?(\d+)(?:/|$)/); if (!m) { err('Could not parse set ID from URL'); return; } const setId = m[1]; log(Set ID: ${setId});

// 2. fetch cards (paginated) log('Fetching cards...'); const cards = []; let page = 1, pagingToken = ''; const perPage = 200; while (true) { const qs = new URLSearchParams({ 'filters[studiableContainerId]': setId, 'filters[studiableContainerType]': '1', perPage: String(perPage), page: String(page), }); if (pagingToken) qs.set('pagingToken', pagingToken);

const res = await fetch(`https://quizlet.com/webapi/3.4/studiable-item-documents?${qs}`, { credentials: 'include' });
if (!res.ok) { err(`API returned ${res.status}`); return; }
const data = await res.json();
const resp = data?.responses?.[0];
const items = resp?.models?.studiableItem || [];

for (const it of items) {
  const term = it.cardSides?.[0]?.media?.find(x => x.plainText)?.plainText;
  const def  = it.cardSides?.[1]?.media?.find(x => x.plainText)?.plainText;
  if (term && def) cards.push({ term, def });
}

const total = resp?.paging?.total;
pagingToken = resp?.paging?.token || '';
if (items.length < perPage || (total != null && cards.length >= total)) break;
page++;

} log(Got ${cards.length} cards); if (!cards.length) { err('No cards fetched'); return; }

// build pair lookup: each side knows its partner const pair = new Map(); for (const { term, def } of cards) { pair.set(norm(term), norm(def)); pair.set(norm(def), norm(term)); }

// 3. click start button inside #__next const root = document.getElementById('__next'); if (!root) { err('#__next not found'); return; }

const startRx = /spiel beginnen|start game|jouer|commencer|begin game|empezar|iniciar|gioca/i; let startBtn = [...root.querySelectorAll('button')].find(b => { const lab = (b.getAttribute('aria-label') || '') + ' ' + (b.textContent || ''); return startRx.test(lab); }); if (!startBtn) startBtn = root.querySelector('button[data-testid="assembly-button-primary"]');

if (startBtn) { log(Clicking start: "${(startBtn.getAttribute('aria-label') || startBtn.textContent || '').trim()}"); realClick(startBtn); await sleep(START_WAIT_MS); } else { warn('No start button found (assuming game already running)'); }

// 4. matching loop const getTiles = () => { const nodes = root.querySelectorAll('.FormattedText[aria-label]'); const out = []; for (const n of nodes) { // FormattedText -> .t1s3w3lt -> .c13hkcga -> tile container const tile = n.parentElement?.parentElement?.parentElement; if (!tile || !isVisible(tile)) continue; out.push({ tile, text: n.getAttribute('aria-label') || '' }); } return out; };

log('Matching started'); let matched = 0, stuck = 0, prevCount = -1;

for (let i = 0; i < MAX_ITERS; i++) { const tiles = getTiles();

if (tiles.length === 0) {
  log(`%c✓ Done. Matched ${matched} pairs.`, 'color:#1D9E75;font-weight:bold');
  return;
}

if (tiles.length === prevCount) {
  if (++stuck > 3) { err('Stuck. Remaining:', tiles.map(t => t.text)); return; }
} else { stuck = 0; prevCount = tiles.length; }

// map normalized text -> DOM tile (for currently visible tiles)
const visible = new Map();
for (const t of tiles) {
  const k = norm(t.text);
  if (!visible.has(k)) visible.set(k, t.tile);
}

// find first tile whose partner is also visible
let A, B, aTxt, bTxt;
for (const t of tiles) {
  const partner = pair.get(norm(t.text));
  if (partner && visible.has(partner) && visib

## Pitfall Guide
1. **DOM Scraping Over API Consumption**: Relying on HTML parsing fails with virtualized lists, lazy loading, and framework-rendered components. Always reverse-engineer the internal REST/GraphQL API used by the frontend.
2. **Ignoring Pagination Tokens**: Assuming `page` increments linearly breaks when platforms use cursor-based or token-based pagination. Always track `pagingToken` and validate against `total` counts.
3. **Framework-Blind Click Simulation**: Modern React/Next.js apps ignore native `.click()` or `dispatchEvent('click')`. You must dispatch full `PointerEvent`/`MouseEvent` chains with precise bounding box coordinates to trigger framework event listeners.
4. **Hardcoding Anki Schema Versions**: Anki frequently updates its internal deck format (e.g., V18 with protobuf). Generators must dynamically detect schema versions and abstract config serialization to avoid silent corruption.
5. **Cross-Tab State Race Conditions**: Merging multiple sets requires synchronized tab communication. Use `chrome.storage.local` with atomic updates and debounce mechanisms to prevent overwrites during concurrent exports.
6. **Over-Requesting Extension Permissions**: Requesting broad `host_permissions` triggers Chrome Web Store rejection and user distrust. Scope permissions to `activeTab` and specific API endpoints, requesting additional access only when triggered by user action.

## Deliverables
- **📘 Extension Architecture Blueprint**: Complete flowchart covering URL detection → API pagination → data normalization → multi-format serialization → cross-tab merge logic. Includes endpoint mapping for `/webapi/3.4/studiable-item-documents` and Knowt import routing.
- **✅ Implementation Checklist**: Step-by-step validation protocol for manifest configuration, permission scoping, API response parsing, pagination token handling, Anki V18 schema compliance, and export pipeline testing.
- **⚙️ Configuration Templates**: 
  - `manifest.json` (MV3 compliant, minimal host permissions)
  - `ankipack` preset generator config (calendar-driven review intervals, V18 protobuf schema mapping)
  - Export format serializers (CSV/TXT/JSON/PDF/Anki/Knowt) with normalization rules and delimiter handling