// Game engine: state, chart rendering, quiz mechanics, tab navigation.
// Content lives in quizzes.js; raw data in game_data.js.

const S = GAME_DATA.scenario;
const fmt = n => n.toLocaleString('uk-UA');
const pct = n => (n > 0 ? '+' : '') + n.toFixed(1) + '%';

// Monthly helpers
const ALL_MONTHS = GAME_DATA.monthly_totals.map(d => d.month);
const MO_LABELS = ALL_MONTHS.map(m => {
  const [y, mo] = m.split('-');
  const names = { '01':'Січ','02':'Лют','03':'Бер','04':'Кві','05':'Тра','06':'Чер','07':'Лип','08':'Сер','09':'Вер','10':'Жов','11':'Лис','12':'Гру' };
  return names[mo] + ' ' + y.slice(2);
});
const seg = (m, s) => GAME_DATA.monthly_by_segment.find(d => d.month === m && d.segment === s) || {};
const tot = m => GAME_DATA.monthly_totals.find(d => d.month === m) || {};
const segSeries = (s, f) => ALL_MONTHS.map(m => seg(m, s)[f]);
const totSeries = f => ALL_MONTHS.map(m => tot(m)[f]);
const kFmt = v => v >= 1000 ? (v / 1000).toFixed(0) + 'K' : v;

// Chart helpers
const COLORS = { primary: '#003964', blue: '#00BBCE', green: '#A7C539', red: '#F15B43', orange: '#ff9800' };
const baseOpts = (legend, scaleOverrides) => ({
  plugins: { legend: legend ? { position: 'top', labels: { boxWidth: 14, font: { size: 11 } } } : { display: false }, datalabels: { display: false } },
  scales: { y: { beginAtZero: true, ticks: { callback: kFmt } }, ...scaleOverrides },
  maintainAspectRatio: true,
});
const lineDs = (label, data, color, extra) => ({ label, data, borderColor: color, tension: 0.25, pointRadius: 3, borderWidth: 2, ...extra });
const mkChart = (canvas, type, datasets, labels, opts) => new Chart(document.getElementById(canvas), { type, data: { labels, datasets }, options: opts });
function destroyChart(key) { if (charts[key]) { charts[key].destroy(); delete charts[key]; } }

// State
const state = {
  tabsVisited: new Set(), subViewsVisited: new Set(),
  overviewMode: 'monthly', ridersMode: 'monthly',
  currentSubTab: 'dayofweek',
  insights: { yoyPositive: false, longRidesCollapse: false, casualDropMore: false, mixShift: false, durationParadox: false, conclusionSeasonal: false, conclusionParadox: false },
  quizzes: {}, wrongCount: 0,
  checked: { conclusionSeasonal: false, conclusionParadox: false },
  deadEndLessons: new Set(), submitted: false,
};
const charts = {};

// --- Quiz rendering ---

function renderQuiz(quizId, container) {
  const q = QUIZZES[quizId], solved = state.quizzes[quizId] === 'correct';
  const correctIdx = q.options.findIndex(o => o.correct);
  const el = document.createElement('div');
  el.className = 'quiz-section'; el.id = 'quiz-' + quizId;
  el.innerHTML = `<div class="quiz-prompt">${q.prompt}</div><div class="quiz-options">
    ${q.options.map((o, i) => solved
      ? `<button class="quiz-opt ${i === correctIdx ? 'correct' : 'faded'}" style="pointer-events:none;"><span class="q-icon">${i === correctIdx ? '\u2713' : ''}</span><span>${o.text}</span></button>`
      : `<button class="quiz-opt" id="qopt-${quizId}-${i}" onclick="handleQuizChoice('${quizId}',${i})"><span class="q-icon"></span><span>${o.text}</span></button>`
    ).join('')}</div>
    <div class="quiz-feedback ${solved ? 'visible correct-fb' : ''}" id="qfb-${quizId}">${solved ? q.options[correctIdx].feedback : ''}</div>`;
  container.appendChild(el);
}

function handleQuizChoice(quizId, optIdx) {
  const q = QUIZZES[quizId], opt = q.options[optIdx];
  const fb = document.getElementById('qfb-' + quizId);
  const btn = document.getElementById('qopt-' + quizId + '-' + optIdx);
  if (opt.correct) {
    state.quizzes[quizId] = 'correct';
    btn.classList.add('correct'); btn.querySelector('.q-icon').textContent = '\u2713';
    fb.className = 'quiz-feedback visible correct-fb'; fb.textContent = opt.feedback;
    q.options.forEach((_, i) => { if (i !== optIdx) { const o = document.getElementById('qopt-'+quizId+'-'+i); if (o) o.classList.add('faded'); } });
    if (q.insightKey) unlockInsight(q.insightKey);
    if (q.lessonKey) state.deadEndLessons.add(q.lessonKey);
    const lessonEl = document.getElementById('lesson-' + quizId);
    if (lessonEl) lessonEl.classList.remove('lesson-hidden');
  } else {
    state.wrongCount++;
    btn.classList.add('wrong'); btn.querySelector('.q-icon').textContent = '\u2717';
    fb.className = 'quiz-feedback visible wrong-fb'; fb.textContent = opt.feedback;
    setTimeout(() => { btn.classList.remove('wrong'); btn.classList.add('disabled'); btn.querySelector('.q-icon').textContent = ''; }, 2000);
  }
  updateViewCount();
}

function quizInto(spotId, quizId) { const s = document.getElementById(spotId); if (!s) return; s.innerHTML = ''; renderQuiz(quizId, s); }

// --- Insight cards ---

function renderInsightCards() {
  document.getElementById('observationCards').innerHTML = OBSERVATIONS.map(insightCardHTML).join('');
  document.getElementById('conclusionCards').innerHTML = CONCLUSIONS.map(insightCardHTML).join('');
  document.getElementById('connectionCard').innerHTML = '';
}
function insightCardHTML(o) {
  const isCon = o.tag === 'conclusion';
  const unlocked = state.insights[o.key];
  if (!unlocked) {
    // Fully hidden: just a placeholder
    return `<div class="insight-card locked ${isCon ? 'conclusion' : ''}" id="card-${o.key}">
      <div class="insight-placeholder">\uD83D\uDD12 \u0420\u043E\u0437\u0431\u043B\u043E\u043A\u0443\u0454\u0442\u044C\u0441\u044F, \u043A\u043E\u043B\u0438 \u043F\u0440\u0430\u0432\u0438\u043B\u044C\u043D\u043E \u0432\u0456\u0434\u043F\u043E\u0432\u0456\u0441\u0442\u0435 \u043D\u0430 \u043F\u0438\u0442\u0430\u043D\u043D\u044F \u0443 \u0432\u043A\u043B\u0430\u0434\u0446\u0456</div>
      ${isCon ? `<div class="insight-check" id="check-${o.key}"></div>` : ''}</div>`;
  }
  const tagLabel = { observation: '\u0441\u043f\u043e\u0441\u0442\u0435\u0440\u0435\u0436\u0435\u043d\u043d\u044f', conclusion: '\u0432\u0438\u0441\u043d\u043e\u0432\u043e\u043a' }[o.tag] || o.tag;
  return `<div class="insight-card unlocked ${isCon ? 'conclusion' : ''}" id="card-${o.key}">
    <div class="insight-text">${o.text}</div><span class="insight-tag ${o.tag}">${tagLabel}</span>
    ${isCon ? `<div class="insight-check ${state.checked[o.key] ? 'checked' : ''}" id="check-${o.key}" onclick="toggleCheck('${o.key}')">${state.checked[o.key] ? '\u2713' : ''}</div>` : ''}</div>`;
}
function unlockInsight(key) {
  if (state.insights[key]) return;
  state.insights[key] = true;
  // Re-render all cards to update from placeholder to content
  renderInsightCards();
  const card = document.getElementById('card-' + key);
  if (card) card.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
  // Conclusion unlock logic
  if (state.insights.casualDropMore && state.insights.yoyPositive) unlockInsight('conclusionSeasonal');
  if (state.insights.mixShift && state.insights.durationParadox) unlockInsight('conclusionParadox');
  if (state.insights.conclusionSeasonal && state.insights.conclusionParadox) {
    const el = document.getElementById('connectionCard');
    if (el && !el.innerHTML) el.innerHTML = `<div class="connection-card"><strong>Одна причина — два симптоми.</strong> Бойові підрозділи (захисні насамперед) пішли на ротацію/підготовку. Це пояснює і падіння обсягу операцій, і зростання загальної ефективності одночасно.</div>`;
  }
  updateSubmit();
}
function toggleCheck(key) {
  if (!state.insights[key]) return;
  state.checked[key] = !state.checked[key];
  const el = document.getElementById('check-' + key);
  el.classList.toggle('checked', state.checked[key]); el.textContent = state.checked[key] ? '\u2713' : '';
  updateSubmit();
}
function updateSubmit() {
  document.getElementById('submitBtn').disabled = !(state.checked.conclusionSeasonal || state.checked.conclusionParadox);
  if (state.insights.conclusionSeasonal || state.insights.conclusionParadox) {
    const h = document.getElementById('submitHint'); h.textContent = 'Позначте висновки, які хочете надіслати, і натисніть кнопку'; h.style.color = '';
  }
}

// --- View tracking ---

function recordView(viewId) {
  (viewId.startsWith('sub:') ? state.subViewsVisited : state.tabsVisited).add(viewId);
  updateViewCount();
}
function updateViewCount() {
  const a = Object.values(state.quizzes).filter(v => v === 'correct').length, w = state.wrongCount;
  const total = Object.keys(QUIZZES).length;
  document.getElementById('viewsTag').textContent = (a > 0 ? `${a}/${total} \u0432\u0456\u0434\u043f\u043e\u0432\u0456\u0434\u0456` : '') + (w > 0 ? ` \u00b7 ${w} \u043f\u043e\u043c\u0438\u043b\u043e\u043a` : '');
}

// --- Tab switching ---

function switchTab(tabId) {
  document.querySelectorAll('.tab-btn').forEach(b => b.classList.toggle('active', b.dataset.tab === tabId));
  document.querySelectorAll('.tab-pane').forEach(p => p.classList.toggle('active', p.id === 'pane-' + tabId));
  recordView(tabId);
  ({ overview: renderOverview, breakdowns: renderBreakdowns, riders: renderRiders, duration: renderDuration })[tabId]();
}

// --- Overview tab ---

function toggleOverview(mode) {
  state.overviewMode = mode;
  document.querySelectorAll('#pane-overview .toggle-btn').forEach(b => b.classList.toggle('active', b.textContent === (mode === 'monthly' ? 'Місячна' : 'Денна')));
  renderOverview();
}
function renderOverview() {
  destroyChart('overviewRides'); destroyChart('overviewDuration');
  const spot = document.getElementById('quiz-overview-spot'); spot.innerHTML = '';

  const monthShort = ['Січ','Лют','Бер','Кві','Тра','Чер','Лип','Сер','Вер','Жов','Лис','Гру'];
  if (state.overviewMode === 'monthly') {
    charts.overviewRides = mkChart('chartOverviewRides', 'line',
      [lineDs('Кількість операцій', totSeries('rides'), COLORS.primary, { backgroundColor: 'rgba(0,57,100,0.08)', fill: true })],
      MO_LABELS, baseOpts(false));
    charts.overviewDuration = mkChart('chartOverviewDuration', 'line',
      [lineDs('% успіху', totSeries('avg_duration'), COLORS.primary, { backgroundColor: 'rgba(0,57,100,0.08)', fill: true })],
      MO_LABELS, baseOpts(false, { y: { beginAtZero: false, ticks: { callback: v => v + '%' } } }));
  } else {
    // Daily view
    const daily = GAME_DATA.daily_totals;
    const labels = daily.map((d) => {
      const dt = new Date(d.date);
      return (dt.getDate() === 1) ? monthShort[dt.getMonth()] + " '" + String(dt.getFullYear()).slice(2) : '';
    });
    charts.overviewRides = mkChart('chartOverviewRides', 'line',
      [{ label: 'Кількість операцій (день)', data: daily.map(d => d.rides), borderColor: COLORS.primary, backgroundColor: 'rgba(0,57,100,0.06)', fill: true, tension: 0.1, pointRadius: 0, borderWidth: 1.5 }],
      labels, { ...baseOpts(false), scales: { y: { beginAtZero: true, ticks: { callback: kFmt } }, x: { ticks: { maxRotation: 45, autoSkip: true, maxTicksLimit: 14 } } } });
    charts.overviewDuration = mkChart('chartOverviewDuration', 'line',
      [{ label: '% успіху (день)', data: daily.map(d => d.avg_duration), borderColor: COLORS.primary, backgroundColor: 'rgba(0,57,100,0.06)', fill: true, tension: 0.1, pointRadius: 0, borderWidth: 1.5 }],
      labels, { ...baseOpts(false), scales: { y: { beginAtZero: false, ticks: { callback: v => v + '%' } }, x: { ticks: { maxRotation: 45, autoSkip: true, maxTicksLimit: 14 } } } });
  }
  renderQuiz('overview', spot);
}

// --- Breakdowns tab ---

function switchSubTab(subId) {
  state.currentSubTab = subId;
  document.querySelectorAll('.sub-tab-btn').forEach(b => b.classList.toggle('active', b.dataset.subtab === subId));
  recordView('sub:' + subId); renderBreakdowns();
}
function renderBreakdowns() {
  const c = document.getElementById('breakdowns-content'); c.innerHTML = '';
  destroyChart('bd1'); destroyChart('bd2');
  ({ dayofweek: renderDayOfWeek, hourly: renderHourly, biketypes: renderBikeTypes, duration_buckets: renderDurationBuckets, stations: renderStations })[state.currentSubTab](c);
}

function renderDayOfWeek(container) {
  const days = ['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday'];
  const dayLabels = { Monday:'Пн', Tuesday:'Вт', Wednesday:'Ср', Thursday:'Чт', Friday:'Пт', Saturday:'Сб', Sunday:'Нд' };
  const octData = days.map(d => { const r = GAME_DATA.day_of_week.find(x => x.month === '2023-10' && x.weekday === d); return r ? r.rides : 0; });
  const novData = days.map(d => { const r = GAME_DATA.day_of_week.find(x => x.month === '2023-11' && x.weekday === d); return r ? r.rides : 0; });
  const changes = days.map((_, i) => octData[i] > 0 ? ((novData[i] - octData[i]) / octData[i] * 100) : 0);

  container.innerHTML = `
    <div class="chart-card"><h3>Кількість операцій за днем тижня: жовтень vs листопад</h3><canvas id="chartBd1"></canvas></div>
    <div class="chart-card"><h3>% зміни по дням (жовтень &rarr; листопад)</h3><canvas id="chartBd2"></canvas></div>
    <div id="quiz-dayofweek-spot"></div>
    <div class="lesson-card lesson-hidden" id="lesson-dayofweek"><h4>Аналітичний урок</h4><p>Порівнюючи місяці, перевір спершу їхню *календарну структуру*: скільки в кожному кожного дня тижня. Місяці з різною кількістю буднів і вихідних можуть створювати фальшиві патерни в "сирих" сумах.</p></div>`;

  charts.bd1 = new Chart(document.getElementById('chartBd1'), {
    type: 'bar', data: { labels: days.map(d => dayLabels[d]),
      datasets: [
        { label: 'Жовтень', data: octData, backgroundColor: COLORS.primary },
        { label: 'Листопад', data: novData, backgroundColor: COLORS.blue },
      ]}, options: { plugins: { legend: { position: 'top', labels: { boxWidth: 14 } }, datalabels: { display: false } }, scales: { y: { beginAtZero: true, ticks: { callback: kFmt } } } }
  });
  charts.bd2 = new Chart(document.getElementById('chartBd2'), {
    type: 'bar', data: { labels: days.map(d => dayLabels[d]),
      datasets: [{ data: changes, backgroundColor: changes.map(c => c > -10 ? COLORS.green : c > -30 ? COLORS.orange : COLORS.red) }] },
    options: { plugins: { legend: { display: false }, datalabels: { display: true, color: '#333', font: { weight: 'bold', size: 11 }, formatter: v => v.toFixed(1) + '%', anchor: 'end', align: 'top' } }, scales: { y: { ticks: { callback: v => v + '%' } } } },
    plugins: [ChartDataLabels]
  });
  quizInto('quiz-dayofweek-spot', 'dayofweek');
}

function renderHourly(container) {
  const hours = Array.from({ length: 24 }, (_, i) => i);
  const hlabels = hours.map(h => h % 3 === 0 ? h + ':00' : '');
  const getTotal = mo => hours.map(h => { const d = GAME_DATA.hourly_totals.find(x => x.month === mo && x.hour === h); return d ? d.rides : 0; });

  container.innerHTML = `
    <div class="chart-card"><h3>Операції за годиною доби: жовтень vs листопад</h3><canvas id="chartBd1"></canvas></div>
    <div id="quiz-hourly-spot"></div>
    <div class="lesson-card lesson-hidden" id="lesson-hourly"><h4>Аналітичний урок</h4><p>Коли дві криві за часом *ідентичні за формою* — час доби нічого не пояснює. Це чиста зміна обсягу, не зміна патерну. Шукай розрізи, де <em>форма</em> розподілу змінюється.</p></div>`;

  charts.bd1 = new Chart(document.getElementById('chartBd1'), {
    type: 'line', data: { labels: hlabels, datasets: [
      { label: 'Жовтень', data: getTotal('2023-10'), borderColor: COLORS.primary, fill: true, backgroundColor: COLORS.primary + '1a', tension: 0.3, pointRadius: 0 },
      { label: 'Листопад', data: getTotal('2023-11'), borderColor: COLORS.blue, fill: false, tension: 0.3, pointRadius: 0 },
    ]}, options: { plugins: { legend: { position: 'top', labels: { boxWidth: 14 } }, datalabels: { display: false } }, scales: { y: { beginAtZero: true, ticks: { callback: kFmt } }, x: { ticks: { autoSkip: true, maxTicksLimit: 8 } } }, aspectRatio: 2.2 }
  });
  quizInto('quiz-hourly-spot', 'hourly');
}

function renderBikeTypes(container) {
  // Fixed order for narrative: prep first (training, logistics), then combat (recon, fire_support, defensive)
  const types = ['training', 'logistics', 'recon', 'fire_support', 'defensive'];
  const typeLabels = {
    training: 'Тренування', logistics: 'Логістика',
    recon: 'Розвідка', fire_support: 'Вогневе ураження', defensive: 'Оборонні дії',
  };
  const octData = types.map(t => { const r = GAME_DATA.bike_type.find(x => x.month === '2023-10' && x.bike_type === t); return r ? r.rides : 0; });
  const novData = types.map(t => { const r = GAME_DATA.bike_type.find(x => x.month === '2023-11' && x.bike_type === t); return r ? r.rides : 0; });
  const octEff = types.map(t => { const r = GAME_DATA.bike_type.find(x => x.month === '2023-10' && x.bike_type === t); return r ? r.avg_duration : 0; });
  const novEff = types.map(t => { const r = GAME_DATA.bike_type.find(x => x.month === '2023-11' && x.bike_type === t); return r ? r.avg_duration : 0; });
  const changes = types.map((_, i) => octData[i] > 0 ? ((novData[i] - octData[i]) / octData[i] * 100) : 0);

  container.innerHTML = `
    <div class="chart-card"><h3>Кількість операцій за категорією: жовтень vs листопад</h3><canvas id="chartBd1"></canvas></div>
    <div class="chart-card"><h3>Ефективність (% успіху) за категорією</h3><canvas id="chartBd2"></canvas></div>
    <div id="quiz-biketypes-spot"></div>
    <div class="lesson-card lesson-hidden" id="lesson-biketypes"><h4>Аналітичний урок</h4><p>Коли категорії рухаються в *різні* боки — це сигнал структурної зміни. Подивись на частки до й після, не лише на абсолютні цифри. *Кожна категорія окремо* може бути стабільною, а загальна — рухатися лише через зміну ваг.</p></div>`;

  charts.bd1 = new Chart(document.getElementById('chartBd1'), {
    type: 'bar', data: { labels: types.map(t => typeLabels[t]),
      datasets: [
        { label: 'Жовтень', data: octData, backgroundColor: COLORS.primary },
        { label: 'Листопад', data: novData, backgroundColor: COLORS.blue },
      ]}, options: { plugins: { legend: { position: 'top', labels: { boxWidth: 14 } }, datalabels: { display: true, color: '#333', font: { size: 10 }, formatter: (v, ctx) => { const i = ctx.dataIndex; const ci = ctx.datasetIndex; if (ci === 1) return changes[i].toFixed(1) + '%'; return ''; }, anchor: 'end', align: 'top' } }, scales: { y: { beginAtZero: true, ticks: { callback: kFmt } } } },
    plugins: [ChartDataLabels]
  });
  charts.bd2 = new Chart(document.getElementById('chartBd2'), {
    type: 'bar', data: { labels: types.map(t => typeLabels[t]),
      datasets: [
        { label: 'Жовтень', data: octEff, backgroundColor: COLORS.primary },
        { label: 'Листопад', data: novEff, backgroundColor: COLORS.blue },
      ]}, options: { plugins: { legend: { position: 'top', labels: { boxWidth: 14 } }, datalabels: { display: true, color: '#333', font: { size: 10 }, formatter: v => v.toFixed(1) + '%', anchor: 'end', align: 'top' } }, scales: { y: { beginAtZero: true, max: 100, ticks: { callback: v => v + '%' } } } },
    plugins: [ChartDataLabels]
  });
  quizInto('quiz-biketypes-spot', 'biketypes');
}

function renderDurationBuckets(container) {
  const buckets = ['small', 'medium', 'large'];
  const bucketLabels = { small: 'Мала', medium: 'Середня', large: 'Велика' };
  const octData = buckets.map(b => { const r = GAME_DATA.duration_buckets.find(x => x.month === '2023-10' && x.bucket === b); return r ? r.rides : 0; });
  const novData = buckets.map(b => { const r = GAME_DATA.duration_buckets.find(x => x.month === '2023-11' && x.bucket === b); return r ? r.rides : 0; });
  const changes = buckets.map((_, i) => octData[i] > 0 ? ((novData[i] - octData[i]) / octData[i] * 100) : 0);

  container.innerHTML = `
    <div class="chart-card"><h3>% зміни за масштабом операцій (жовтень &rarr; листопад)</h3><canvas id="chartBd1"></canvas></div>
    <div class="chart-card"><h3>Операції за масштабом: жовтень vs листопад</h3><canvas id="chartBd2"></canvas></div>
    <div id="quiz-duration_buckets-spot"></div>
    <div class="lesson-card lesson-hidden" id="lesson-duration_buckets"><h4>Аналітичний урок</h4><p>Якщо різні масштаби операцій рухаються в один бік приблизно однаково — це не пояснення зміни. Шукай розрізи, де *відсоткові зміни розходяться*.</p></div>`;

  const bucketDisplayLabels = buckets.map(b => bucketLabels[b]);
  charts.bd1 = new Chart(document.getElementById('chartBd1'), {
    type: 'bar', data: { labels: bucketDisplayLabels,
      datasets: [{ data: changes, backgroundColor: changes.map(c => c > -30 ? COLORS.green : c > -45 ? COLORS.orange : COLORS.red) }] },
    options: { plugins: { legend: { display: false }, datalabels: { display: true, color: '#333', font: { weight: 'bold', size: 12 }, formatter: v => v.toFixed(1) + '%', anchor: 'end', align: 'top' } }, scales: { y: { ticks: { callback: v => v + '%' } } } },
    plugins: [ChartDataLabels]
  });
  charts.bd2 = new Chart(document.getElementById('chartBd2'), {
    type: 'bar', data: { labels: bucketDisplayLabels,
      datasets: [
        { label: 'Жовтень', data: octData, backgroundColor: COLORS.primary },
        { label: 'Листопад', data: novData, backgroundColor: COLORS.blue },
      ]}, options: { plugins: { legend: { position: 'top', labels: { boxWidth: 14 } }, datalabels: { display: false } }, scales: { y: { beginAtZero: true, ticks: { callback: kFmt } } } }
  });
  quizInto('quiz-duration_buckets-spot', 'duration_buckets');
}

function renderStations(container) {
  const data = GAME_DATA.station_comparison.slice(0, 10);

  container.innerHTML = `
    <div class="chart-card"><h3>Підрозділи — % зміни обсягу (жовтень &rarr; листопад)</h3><canvas id="chartBd1"></canvas></div>
    <div id="quiz-stations-spot"></div>
    <div class="lesson-card lesson-hidden" id="lesson-stations"><h4>Аналітичний урок</h4><p>Коли усі підрозділи рухаються в один бік приблизно однаково — причина системна, не локальна. Не шукай "винного" — шукай фактор, що вплинув на всіх.</p></div>`;

  charts.bd1 = new Chart(document.getElementById('chartBd1'), {
    type: 'bar', data: { labels: data.map(d => d.station.length > 25 ? d.station.substring(0, 25) + '\u2026' : d.station),
      datasets: [{ data: data.map(d => d.change_pct), backgroundColor: data.map(d => d.change_pct < -40 ? COLORS.red : d.change_pct < -25 ? COLORS.orange : COLORS.green) }] },
    options: { indexAxis: 'y', plugins: { legend: { display: false }, tooltip: { callbacks: { label: ctx => ctx.raw.toFixed(1) + '%' } }, datalabels: { display: true, anchor: 'end', align: 'right', color: '#333', font: { weight: 'bold', size: 11 }, formatter: v => v.toFixed(1) + '%' } }, scales: { x: { ticks: { callback: v => v + '%' } } } },
    plugins: [ChartDataLabels]
  });
  quizInto('quiz-stations-spot', 'stations');
}

// --- Rider Types tab ---

function toggleRiders(mode) {
  state.ridersMode = mode;
  document.querySelectorAll('#pane-riders .toggle-btn').forEach(b => b.classList.toggle('active', b.textContent === (mode === 'monthly' ? 'Місячна' : 'Денна')));
  renderRiders();
}
function renderRiders() {
  destroyChart('riderRides'); destroyChart('riderMix');
  const spot = document.getElementById('quiz-riders-spot'); spot.innerHTML = '';

  const monthShortR = ['Січ','Лют','Бер','Кві','Тра','Чер','Лип','Сер','Вер','Жов','Лис','Гру'];
  if (state.ridersMode === 'monthly') {
    charts.riderRides = mkChart('chartRiderRides', 'line', [
      lineDs('Підготовчі', segSeries('preparation', 'rides'), COLORS.primary, { backgroundColor: 'rgba(0,57,100,0.06)', fill: true }),
      lineDs('Бойові', segSeries('combat', 'rides'), COLORS.blue, { backgroundColor: 'rgba(0,187,206,0.06)', fill: true }),
    ], MO_LABELS, baseOpts(true));

    // Show share of preparation (the GROWING segment) — highlights the mix shift visually
    const shares = ALL_MONTHS.map(m => {
      const p = seg(m, 'preparation').rides || 0, t = tot(m).rides || 1;
      return Math.round(p / t * 100);
    });
    charts.riderMix = new Chart(document.getElementById('chartRiderMix'), {
      type: 'line', data: { labels: MO_LABELS, datasets: [{ label: 'Частка підготовчих %', data: shares, borderColor: COLORS.primary, backgroundColor: 'rgba(0,57,100,0.1)', fill: true, tension: 0.25, pointRadius: 5 }] },
      options: { plugins: { legend: { display: false }, datalabels: { display: true, color: COLORS.primary, font: { weight: 'bold', size: 11 }, formatter: v => v + '%', anchor: 'end', align: 'top' } }, scales: { y: { min: 0, max: 70, ticks: { callback: v => v + '%' } } } },
      plugins: [ChartDataLabels]
    });
  } else {
    // Daily view by segment
    const daily = GAME_DATA.daily_by_segment;
    const dates = [...new Set(daily.map(d => d.date))];
    const labels = dates.map(d => {
      const dt = new Date(d);
      return dt.getDate() === 1 ? monthShortR[dt.getMonth()] + " '" + String(dt.getFullYear()).slice(2) : '';
    });
    const prepRides = dates.map(d => { const r = daily.find(x => x.date === d && x.segment === 'preparation'); return r ? r.rides : 0; });
    const combatRides = dates.map(d => { const r = daily.find(x => x.date === d && x.segment === 'combat'); return r ? r.rides : 0; });

    charts.riderRides = mkChart('chartRiderRides', 'line', [
      { label: 'Підготовчі', data: prepRides, borderColor: COLORS.primary, tension: 0.1, pointRadius: 0, borderWidth: 1.5, fill: true, backgroundColor: 'rgba(0,57,100,0.06)' },
      { label: 'Бойові', data: combatRides, borderColor: COLORS.blue, tension: 0.1, pointRadius: 0, borderWidth: 1.5, fill: true, backgroundColor: 'rgba(0,187,206,0.06)' },
    ], labels, { ...baseOpts(true), scales: { y: { beginAtZero: true, ticks: { callback: kFmt } }, x: { ticks: { maxRotation: 45, autoSkip: true, maxTicksLimit: 14 } } } });

    // Daily preparation share
    const shareData = dates.map(d => {
      const p = daily.find(x => x.date === d && x.segment === 'preparation');
      const c = daily.find(x => x.date === d && x.segment === 'combat');
      const pv = p ? p.rides : 0, cv = c ? c.rides : 0;
      return pv + cv > 0 ? Math.round(pv / (pv + cv) * 100) : 0;
    });
    charts.riderMix = mkChart('chartRiderMix', 'line',
      [{ label: 'Частка підготовчих %', data: shareData, borderColor: COLORS.primary, tension: 0.1, pointRadius: 0, borderWidth: 1.5, fill: true, backgroundColor: 'rgba(0,57,100,0.1)' }],
      labels, { ...baseOpts(false), scales: { y: { min: 0, max: 70, ticks: { callback: v => v + '%' } }, x: { ticks: { maxRotation: 45, autoSkip: true, maxTicksLimit: 14 } } } });
  }

  renderQuiz('riders_reveal', spot);
}

// --- Duration tab ---

function renderDuration() {
  destroyChart('durChange'); destroyChart('durTime');
  const oc = seg('2023-10', 'combat').avg_duration, nc = seg('2023-11', 'combat').avg_duration;
  const om = seg('2023-10', 'preparation').avg_duration, nm = seg('2023-11', 'preparation').avg_duration;
  const cc = (nc - oc) / oc * 100, cm = (nm - om) / om * 100, ca = S.duration_change_pct;

  // Vertical grouped bar — Oct and Nov side by side for each group, plus overall
  const groups = ['Бойові', 'Підготовчі', 'Загалом'];
  const octVals = [oc, om, S.prior_avg_duration];
  const novVals = [nc, nm, S.focus_avg_duration];
  const changePcts = [cc, cm, ca];

  charts.durChange = new Chart(document.getElementById('chartDurChange'), {
    type: 'bar', data: { labels: groups,
      datasets: [
        { label: 'Жовтень', data: octVals, backgroundColor: COLORS.primary },
        { label: 'Листопад', data: novVals, backgroundColor: COLORS.blue },
      ]},
    options: {
      plugins: {
        legend: { position: 'top', labels: { boxWidth: 14 } },
        datalabels: { display: true, color: '#333', font: { size: 11, weight: 'bold' },
          formatter: (v, ctx) => {
            const i = ctx.dataIndex;
            if (ctx.datasetIndex === 1) return v.toFixed(1) + '% (' + (changePcts[i] >= 0 ? '+' : '') + changePcts[i].toFixed(1) + ' п.п.)';
            return v.toFixed(1) + '%';
          }, anchor: 'end', align: 'top' },
      },
      scales: { y: { beginAtZero: true, max: 100, title: { display: true, text: '% успіху' }, ticks: { callback: v => v + '%' } } },
    },
    plugins: [ChartDataLabels]
  });

  // Efficiency over time with all months — per segment + overall
  charts.durTime = mkChart('chartDurTime', 'line', [
    lineDs('Бойові', segSeries('combat', 'avg_duration'), COLORS.blue),
    lineDs('Підготовчі', segSeries('preparation', 'avg_duration'), COLORS.primary),
    lineDs('Загалом', totSeries('avg_duration'), COLORS.red, { borderDash: [5, 5], pointRadius: 2, borderWidth: 2 }),
  ], MO_LABELS, baseOpts(true, { y: { beginAtZero: false, ticks: { callback: v => v + '%' } } }));

  // Show mix quiz first (now student can see per-group durations), then the composition effect
  const spot = document.getElementById('quiz-duration-spot');
  spot.innerHTML = '';
  renderQuiz('riders_mix', spot);
  renderQuiz('duration_paradox', spot);
}

// --- Submit & summary ---

function submitAnswer() {
  if (state.submitted) return;
  state.submitted = true;
  if (!(state.checked.conclusionSeasonal && state.checked.conclusionParadox)) {
    state.submitted = false;
    const hint = document.getElementById('submitHint'); hint.style.color = '#e65100';
    hint.textContent = state.checked.conclusionSeasonal ? 'Структуру падіння обсягу зрозуміли. А зростання ефективності — як його пояснити?'
      : state.checked.conclusionParadox ? 'Зміну композиції знайшли. А падіння обсягу — це справді проблема? Поверніться до Загального огляду.'
      : 'Спочатку оберіть висновки, які хочете надіслати.';
    return;
  }
  showSummary();
}
function showSummary() {
  const n22 = GAME_DATA.yoy_totals.find(d => d.month === '2022-11'), n23 = GAME_DATA.yoy_totals.find(d => d.month === '2023-11');
  const yoyPct = ((n23.rides - n22.rides) / n22.rides * 100).toFixed(1);
  const oc = seg('2023-10', 'combat').avg_duration, om = seg('2023-10', 'preparation').avg_duration;
  const ocShare = Math.round(seg('2023-10', 'combat').rides / S.prior_rides * 100), ncShare = Math.round(seg('2023-11', 'combat').rides / S.focus_rides * 100);
  const answered = Object.values(state.quizzes).filter(v => v === 'correct').length;
  const total = Object.keys(QUIZZES).length;
  const bonus = [...state.deadEndLessons].map(k => LESSON_NAMES[k]).filter(Boolean);

  document.getElementById('summaryBox').innerHTML = `
    <h2>\u0420\u043e\u0437\u0441\u043b\u0456\u0434\u0443\u0432\u0430\u043d\u043d\u044f \u0437\u0430\u0432\u0435\u0440\u0448\u0435\u043d\u043e</h2>
    <div class="summary-score"><span class="big">${answered}/${total} \u043f\u0438\u0442\u0430\u043d\u044c</span><span class="sub">\u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d\u043e \u00b7 ${state.wrongCount} \u043f\u043e\u043c\u0438\u043b\u043a\u043e\u0432\u0438\u0445 \u0441\u043f\u0440\u043e\u0431</span></div>
    <div class="s-card reframe"><h3>\u0420\u0435\u0430\u043b\u044c\u043d\u043e\u0457 \u043e\u043f\u0435\u0440\u0430\u0446\u0456\u0439\u043d\u043e\u0457 "\u043f\u0435\u0440\u0435\u043c\u043e\u0433\u0438" \u043d\u0435\u043c\u0430\u0454</h3>
      <p>\u0411\u0435\u0437 \u0441\u0435\u0433\u043c\u0435\u043d\u0442\u0430\u0446\u0456\u0457 \u043a\u043e\u043c\u0430\u043d\u0434\u0438\u0440 \u043c\u0456\u0433 \u0437\u0440\u043e\u0431\u0438\u0442\u0438 \u0432\u0438\u0441\u043d\u043e\u0432\u043e\u043a \u043f\u0440\u043e \u0440\u0435\u0430\u043b\u044c\u043d\u0435 \u043f\u043e\u043a\u0440\u0430\u0449\u0435\u043d\u043d\u044f \u043d\u0430 \u043e\u0441\u043d\u043e\u0432\u0456 \u043e\u043c\u0430\u043d\u043b\u0438\u0432\u043e\u0457 \u0430\u0433\u0440\u0435\u0433\u043e\u0432\u0430\u043d\u043e\u0457 \u0446\u0438\u0444\u0440\u0438. \u041d\u0430\u0441\u043f\u0440\u0430\u0432\u0434\u0456 \u2014 \u043a\u043e\u0436\u0435\u043d \u0441\u0435\u0433\u043c\u0435\u043d\u0442 \u043e\u043a\u0440\u0435\u043c\u043e \u0441\u0442\u0430\u0431\u0456\u043b\u044c\u043d\u0438\u0439; \u0440\u0443\u0445\u0430\u0454\u0442\u044c\u0441\u044f \u043b\u0438\u0448\u0435 \u043a\u043e\u043c\u043f\u043e\u0437\u0438\u0446\u0456\u044f.</p></div>
    <div class="s-card"><h3>\u0412\u0438\u0441\u043d\u043e\u0432\u043e\u043a 1: \u043f\u0430\u0434\u0456\u043d\u043d\u044f \u043e\u0431\u0441\u044f\u0433\u0443 \u2014 \u0441\u0442\u0440\u0443\u043a\u0442\u0443\u0440\u043d\u0438\u0439 \u0437\u0441\u0443\u0432</h3>
      <p>\u0411\u043e\u0439\u043e\u0432\u0456 \u043f\u0456\u0434\u0440\u043e\u0437\u0434\u0456\u043b\u0438 (\u043e\u0441\u043e\u0431\u043b\u0438\u0432\u043e \u043e\u0431\u043e\u0440\u043e\u043d\u043d\u0456) \u0441\u043a\u043e\u0440\u043e\u0442\u0438\u043b\u0438 \u0430\u043a\u0442\u0438\u0432\u043d\u0456\u0441\u0442\u044c \u2014 \u0447\u0430\u0441\u0442\u043a\u0430 \u0432\u043f\u0430\u043b\u0430 \u0437 ~85% \u0434\u043e ~50%. \u041f\u0456\u0434\u0433\u043e\u0442\u043e\u0432\u0447\u0456 (\u0442\u0440\u0435\u043d\u0443\u0432\u0430\u043d\u043d\u044f, \u043b\u043e\u0433\u0456\u0441\u0442\u0438\u043a\u0430) \u043d\u0430\u0442\u043e\u043c\u0456\u0441\u0442\u044c *\u0432\u0438\u0440\u043e\u0441\u043b\u0438* \u0432 \u043e\u0431\u0441\u044f\u0437\u0456. \u0426\u0435 \u043d\u0435 \u043f\u0440\u043e\u0441\u0442\u043e "\u0441\u0442\u0430\u043b\u043e \u043c\u0435\u043d\u0448\u0435" \u2014 \u0446\u0435 \u043f\u0435\u0440\u0435\u0440\u043e\u0437\u043f\u043e\u0434\u0456\u043b.</p>
      <div class="s-metrics"><div class="s-metric"><div class="sm-label">\u041b\u0438\u0441 2022</div><div class="sm-val">${fmt(n22.rides)}</div></div>
        <div class="s-metric"><div class="sm-label">\u041b\u0438\u0441 2023</div><div class="sm-val">${fmt(n23.rides)}</div><div class="sm-delta" style="color:#2e7d32;">${pct(parseFloat(yoyPct))} YoY</div></div></div>
      <p style="margin-top:8px;"><strong>\u0423\u0440\u043e\u043a:</strong> \u0437\u0430\u0432\u0436\u0434\u0438 \u043f\u0438\u0442\u0430\u0439 <em>"\u043f\u043e\u0440\u0456\u0432\u043d\u044f\u043d\u043e \u0437 \u0447\u0438\u043c?"</em>. \u0406 \u043a\u043e\u043b\u0438 \u0446\u0438\u0444\u0440\u0430 \u0440\u0443\u0445\u0430\u0454\u0442\u044c\u0441\u044f \u2014 \u0441\u043f\u0435\u0440\u0448\u0443 \u043f\u0435\u0440\u0435\u0432\u0456\u0440, \u0447\u0438 \u0440\u0443\u0445\u0430\u0454\u0442\u044c\u0441\u044f \u043a\u043e\u043c\u043f\u043e\u0437\u0438\u0446\u0456\u044f.</p></div>
    <div class="s-card"><h3>\u0412\u0438\u0441\u043d\u043e\u0432\u043e\u043a 2: \u0437\u0440\u043e\u0441\u0442\u0430\u043d\u043d\u044f \u0435\u0444\u0435\u043a\u0442\u0438\u0432\u043d\u043e\u0441\u0442\u0456 \u2014 \u0435\u0444\u0435\u043a\u0442 \u043a\u043e\u043c\u043f\u043e\u0437\u0438\u0446\u0456\u0457</h3>
      <p>\u041f\u0456\u0434\u0433\u043e\u0442\u043e\u0432\u0447\u0456 \u043e\u043f\u0435\u0440\u0430\u0446\u0456\u0457 \u043c\u0430\u044e\u0442\u044c \u0432\u0438\u0449\u0443 \u0431\u0430\u0437\u043e\u0432\u0443 \u0435\u0444\u0435\u043a\u0442\u0438\u0432\u043d\u0456\u0441\u0442\u044c (~${om.toFixed(1)}%), \u0431\u043e\u0439\u043e\u0432\u0456 \u2014 \u043d\u0438\u0436\u0447\u0443 (~${oc.toFixed(1)}%). \u0423 \u0436\u043e\u0432\u0442\u043d\u0456 \u043f\u0456\u0434\u0433\u043e\u0442\u043e\u0432\u0447\u0438\u0445 \u0431\u0443\u043b\u043e \u043b\u0438\u0448\u0435 <strong>${ocShare}%</strong> \u0432\u0456\u0434 \u0437\u0430\u0433\u0430\u043b\u0443, \u0443 \u043b\u0438\u0441\u0442\u043e\u043f\u0430\u0434\u0456 \u2014 \u0432\u0436\u0435 <strong>${ncShare}%</strong>. \u0417\u0430\u0433\u0430\u043b\u044c\u043d\u0430 \u0446\u0438\u0444\u0440\u0430 \u0437\u0440\u043e\u0441\u043b\u0430 \u043b\u0438\u0448\u0435 \u0442\u043e\u043c\u0443, \u0449\u043e \u0447\u0430\u0441\u0442\u043a\u0430 "\u043b\u0435\u0433\u0448\u0438\u0445" \u043c\u0456\u0441\u0456\u0439 \u0437\u0431\u0456\u043b\u044c\u0448\u0438\u043b\u0430\u0441\u044c \u2014 \u0430 \u043d\u0435 \u0442\u043e\u043c\u0443, \u0449\u043e \u0445\u0442\u043e\u0441\u044c \u0441\u0442\u0430\u0432 \u0435\u0444\u0435\u043a\u0442\u0438\u0432\u043d\u0456\u0448\u0438\u043c.</p>
      <p><strong>\u0423\u0440\u043e\u043a:</strong> \u043a\u043e\u043b\u0438 \u0437\u043c\u0456\u043d\u044e\u0454\u0442\u044c\u0441\u044f \u043c\u0456\u043a\u0441 \u0433\u0440\u0443\u043f, \u0430\u0433\u0440\u0435\u0433\u0430\u0442 \u0440\u0443\u0445\u0430\u0454\u0442\u044c\u0441\u044f \u043d\u0430\u0432\u0456\u0442\u044c \u044f\u043a\u0449\u043e \u0436\u043e\u0434\u043d\u0430 \u0433\u0440\u0443\u043f\u0430 \u043d\u0435 \u0437\u043c\u0456\u043d\u0438\u043b\u0430 \u043f\u043e\u0432\u0435\u0434\u0456\u043d\u043a\u0438. \u0417\u0430\u0432\u0436\u0434\u0438 \u0441\u0435\u0433\u043c\u0435\u043d\u0442\u0443\u0439, \u043f\u0435\u0440\u0448 \u043d\u0456\u0436 \u0440\u043e\u0431\u0438\u0442\u0438 \u0432\u0438\u0441\u043d\u043e\u0432\u043e\u043a.</p></div>
    <div class="s-card connection"><h3>\u041e\u0434\u043d\u0430 \u043f\u0440\u0438\u0447\u0438\u043d\u0430 \u2014 \u0434\u0432\u0430 \u0441\u0438\u043c\u043f\u0442\u043e\u043c\u0438</h3>
      <p>\u0411\u043e\u0439\u043e\u0432\u0456 \u043f\u0456\u0434\u0440\u043e\u0437\u0434\u0456\u043b\u0438 \u043d\u0430 \u0440\u043e\u0442\u0430\u0446\u0456\u0457/\u043f\u0456\u0434\u0433\u043e\u0442\u043e\u0432\u0446\u0456. \u0426\u0435 \u043f\u043e\u044f\u0441\u043d\u044e\u0454 \u0456 \u043f\u0430\u0434\u0456\u043d\u043d\u044f \u043e\u0431\u0441\u044f\u0433\u0443 \u043e\u043f\u0435\u0440\u0430\u0446\u0456\u0439, \u0456 \u0437\u0440\u043e\u0441\u0442\u0430\u043d\u043d\u044f \u0437\u0430\u0433\u0430\u043b\u044c\u043d\u043e\u0457 \u0446\u0438\u0444\u0440\u0438 \u0435\u0444\u0435\u043a\u0442\u0438\u0432\u043d\u043e\u0441\u0442\u0456 \u2014 \u043e\u0431\u0438\u0434\u0432\u0430 \u0435\u0444\u0435\u043a\u0442\u0438 \u0432\u0456\u0434 \u043e\u0434\u043d\u043e\u0433\u043e \u0441\u0442\u0440\u0443\u043a\u0442\u0443\u0440\u043d\u043e\u0433\u043e \u0437\u0441\u0443\u0432\u0443.</p></div>
    ${bonus.length ? `<div class="s-card"><h3>\u0423\u0440\u043e\u043a\u0438 \u043d\u0430 \u0442\u0443\u043f\u0438\u043a\u043e\u0432\u0438\u0445 \u0433\u0456\u043b\u043a\u0430\u0445</h3><ul class="bonus-list">${bonus.map(l => `<li>${l}</li>`).join('')}</ul></div>` : ''}
    <div class="s-card discussion"><h3>\u041e\u0431\u0433\u043e\u0432\u043e\u0440\u0435\u043d\u043d\u044f</h3>
      <p>1. \u041d\u0430 \u044f\u043a\u0443 \u0432\u043a\u043b\u0430\u0434\u043a\u0443 \u0432\u0438 \u043f\u0456\u0448\u043b\u0438 \u043f\u0435\u0440\u0448\u043e\u044e? \u0429\u043e \u0432\u043e\u043d\u0430 \u0432\u0430\u043c \u043f\u043e\u043a\u0430\u0437\u0430\u043b\u0430?</p><p>2. \u042f\u043a\u0431\u0438 \u0432 \u0434\u0430\u0448\u0431\u043e\u0440\u0434\u0456 \u0431\u0443\u043b\u0430 \u0442\u0456\u043b\u044c\u043a\u0438 \u043e\u0434\u043d\u0430 \u0437\u0430\u0433\u0430\u043b\u044c\u043d\u0430 \u0446\u0438\u0444\u0440\u0430 \u2014 \u0432\u0438 \u0431 \u043f\u043e\u043c\u0456\u0442\u0438\u043b\u0438 \u0437\u0441\u0443\u0432 \u043a\u043e\u043c\u043f\u043e\u0437\u0438\u0446\u0456\u0457?</p>
      <p>3. \u0423 \u0432\u0430\u0448\u0456\u0439 \u0440\u0435\u0430\u043b\u044c\u043d\u0456\u0439 \u0440\u043e\u0431\u043e\u0442\u0456 \u2014 \u044f\u043a\u0456 \u043f\u043e\u043a\u0430\u0437\u043d\u0438\u043a\u0438 \u043d\u0430\u0439\u0431\u0456\u043b\u044c\u0448 \u0432\u0440\u0430\u0437\u043b\u0438\u0432\u0456 \u0434\u043e \u0442\u0430\u043a\u0438\u0445 \u0435\u0444\u0435\u043a\u0442\u0456\u0432?</p><p>4. \u0429\u043e \u0431 \u0432\u0438 \u0441\u043a\u0430\u0437\u0430\u043b\u0438 \u043a\u043e\u043c\u0430\u043d\u0434\u0438\u0440\u043e\u0432\u0456, \u044f\u043a\u0431\u0438 \u0432\u0456\u043d \u043f\u0440\u043e\u044f\u0432\u0438\u0432 \u0437\u0430\u0446\u0456\u043a\u0430\u0432\u043b\u0435\u043d\u043d\u044f \u043b\u0438\u0448\u0435 \u0446\u0438\u0444\u0440\u043e\u044e 71%?</p></div>
    <div class="summary-actions"><button onclick="restart()">\u0414\u043e\u0441\u043b\u0456\u0434\u0438\u0442\u0438 \u0437\u0430\u043d\u043e\u0432\u043e</button></div>`;
  document.getElementById('summaryOverlay').classList.add('visible');
}

// --- Restart ---

function restart() {
  state.tabsVisited.clear(); state.subViewsVisited.clear();
  state.overviewMode = 'monthly'; state.ridersMode = 'monthly'; state.currentSubTab = 'dayofweek';
  state.deadEndLessons.clear(); state.submitted = false; state.wrongCount = 0; state.quizzes = {};
  Object.keys(state.insights).forEach(k => state.insights[k] = false);
  Object.keys(state.checked).forEach(k => state.checked[k] = false);
  Object.values(charts).forEach(c => { try { c.destroy(); } catch (e) {} });
  for (const k in charts) delete charts[k];
  document.getElementById('summaryOverlay').classList.remove('visible');
  const intro = document.getElementById('introOverlay');
  if (intro) intro.classList.remove('hidden');
  document.getElementById('submitHint').textContent = 'Пройдіть вкладки і відповідайте на питання, щоб зібрати докази';
  document.getElementById('submitHint').style.color = '';
  renderInsightCards(); switchTab('overview'); toggleOverview('monthly');
}

// --- Init ---

Chart.defaults.font.family = "'Source Sans Pro', sans-serif";
Chart.register(ChartDataLabels);
Chart.defaults.plugins.datalabels = { display: false };
document.getElementById('amRides').textContent = fmt(S.focus_rides);
document.getElementById('amRidesDelta').textContent = pct(S.rides_change_pct) + ' до жовтня';
document.getElementById('amDur').textContent = S.focus_avg_duration.toFixed(1) + '%';
document.getElementById('amDurDelta').textContent = (S.duration_change_pct >= 0 ? '+' : '') + S.duration_change_pct.toFixed(1) + ' п.п. до жовтня';
renderInsightCards(); renderOverview(); state.tabsVisited.add('overview'); updateViewCount();