/* The Knowledge: owned growth layer (site-wide).
   - Referral capture (?ref=) for every Kit form and every form rendered here
   - Welcome note for readers arriving from a friend's link
   - Mid-essay subscribe card
   - Bottom sheets: subscribe (new readers), Sovereign free chapter (known subscribers)
   - Sharer sheet for readers arriving from the email's share buttons (?share=)
   - /join: invite page and the page shown after signing up
   No third-party code. Everything fails quiet: if anything here breaks, the page is untouched. */
(function () {
  'use strict';
  if (window.__tkGrow) return;
  window.__tkGrow = { v: 1 };

  var CDN = 'https://cdn.getmidnight.com/a26398dca6f47b49876cbaffbc9954f9/2026/11/';
  var API = 'https://decision-hacker-fulfilment.davidelikwu.workers.dev';
  var FORM_SUB = '2864506', FORM_SOV = '3758993';
  var MSG = "Thought you'd like this. It's from a newsletter I read every week";
  var DAY = 864e5;
  var doc = document, body = doc.body, qs = new URLSearchParams(location.search);

  /* ---------- storage ---------- */
  function get(k) { try { return JSON.parse(localStorage.getItem(k) || 'null'); } catch (e) { return null; } }
  function set(k, v) { try { localStorage.setItem(k, JSON.stringify(v)); } catch (e) {} }

  /* ---------- referral capture (same rules as before: 30 days, URL wins) ---------- */
  var m = /^[a-z0-9-]{6,40}$/i.exec(qs.get('ref') || ''), refFromUrl = !!m, ref = m ? m[0].toLowerCase() : null;
  if (ref) set('tk_ref', { ref: ref, t: Date.now() });
  else { var s = get('tk_ref'); if (s && Date.now() - s.t < 30 * DAY) ref = s.ref; }
  function stampKitForms() {
    if (!ref) return;
    doc.querySelectorAll('form.formkit-form, form[action*="kit.com/forms"], form[action*="convertkit.com/forms"]').forEach(function (f) {
      var i = f.querySelector('input[name="fields[tk_referred_by]"]');
      if (!i) { i = doc.createElement('input'); i.type = 'hidden'; i.name = 'fields[tk_referred_by]'; f.appendChild(i); i.value = ref; }
      else if (refFromUrl && i.value !== ref) i.value = ref;
    });
  }
  stampKitForms();
  try { new MutationObserver(stampKitForms).observe(doc.documentElement, { childList: true, subtree: true }); } catch (e) {}

  /* ---------- who is this ---------- */
  var share = /^[a-z0-9-]{6,40}$/i.test(qs.get('share') || '') ? qs.get('share').toLowerCase() : null;
  if (share || qs.get('ck_subscriber_id')) set('tk_sub', 1);
  var isSub = !!get('tk_sub');
  var isJoin = body.classList.contains('page-join');
  var article = doc.querySelector('article.ghost-content');
  var isPost = body.classList.contains('post-template') && !!article && !body.className.match(/tag-hash-|tag-decision-hacker/);

  /* ---------- styles ---------- */
  var css = [
    ':root{--tk-bg:#fff;--tk-card:#f7f6f4;--tk-line:#e6e3de;--tk-ink:#262626;--tk-mut:#6f6b66;--tk-acc:#ff4c29;--tk-field:#fff;--tk-field2:#f3f1ed;--tk-dark:#1a1a1a}',
    'html[data-color-scheme=dark]{--tk-bg:#1a1a1a;--tk-card:#232322;--tk-line:#353432;--tk-ink:#e6e6e6;--tk-mut:#a29e98;--tk-field:#121212;--tk-field2:#111;--tk-dark:#2b2a28}',
    '@media (prefers-color-scheme:dark){html[data-color-scheme=system]{--tk-bg:#1a1a1a;--tk-card:#232322;--tk-line:#353432;--tk-ink:#e6e6e6;--tk-mut:#a29e98;--tk-field:#121212;--tk-field2:#111;--tk-dark:#2b2a28}}',
    '.tkx{font-family:"DM Sans",system-ui,sans-serif;color:var(--tk-ink);-webkit-font-smoothing:antialiased;text-align:left;line-height:1.4}',
    '.tkx *{box-sizing:border-box}',
    '.tkx img{margin:0!important;max-width:none;display:block}',
    '.tkx p,.tkx h2,.tkx h3{margin:0!important}',
    '.tkx .serif{font-family:"Source Serif 4","Source Serif Pro",Georgia,serif}',
    '.tkx .mut{color:var(--tk-mut)}',
    '.tkx form.combo{display:flex;align-items:center;gap:6px;margin:0;padding:5px 5px 5px 6px;border-radius:12px;background:var(--tk-field);border:1px solid var(--tk-line)}',
    '.tkx form.combo:focus-within{border-color:var(--tk-acc)}',
    '.tkx form.combo input{flex:1 1 0;width:0;min-width:0;height:40px;margin:0;padding:0 10px;border:0!important;outline:0!important;box-shadow:none!important;background:transparent!important;font:inherit;font-size:16px;color:var(--tk-ink)}',
    '.tkx form.combo input::placeholder{color:var(--tk-mut);opacity:1}',
    '.tkx form.combo button{height:40px;margin:0;padding:0 16px;border:0;border-radius:9px;background:var(--tk-acc);color:#fff;font:inherit;font-size:15px;font-weight:600;white-space:nowrap;cursor:pointer;flex:none}',
    '.tkx form.combo button[disabled]{opacity:.6;cursor:default}',
    '.tkx form.combo.f2{background:var(--tk-field2)}',
    '.tkx form.combo.onbg{background:var(--tk-bg)}',
    '.tkx .tk-err{font-size:13px;color:#c0392b;margin-top:8px}.tkx .tk-err:empty{display:none}',
    '.tkx .tk-done{font-size:15px;line-height:1.45;padding:12px 2px 2px}',
    '.tkx .stars{color:#f5b301;letter-spacing:1px;font-size:12px;white-space:nowrap}',
    '.tkx .faces{display:flex;flex:none}.tkx .faces img{width:24px;height:24px;border-radius:999px;object-fit:cover;box-shadow:0 0 0 2px var(--tk-bg)}.tkx .faces img+img{margin-left:-7px!important}',
    '.tkx .av{border-radius:999px;object-fit:cover;flex:none}',
    '.tk-card{margin:28px 0 30px;padding:18px;border-radius:16px;background:var(--tk-card);border:1px solid var(--tk-line)}',
    '.tk-card .faces img{box-shadow:0 0 0 2px var(--tk-card)}',
    '.tk-note{margin:0 0 26px;padding:16px;border-radius:18px;background:var(--tk-card);border:1px solid var(--tk-line)}',
    '.tk-sheet{position:fixed;left:0;right:0;bottom:0;z-index:9999;padding:10px 20px calc(28px + env(safe-area-inset-bottom));border-radius:22px 22px 0 0;background:var(--tk-bg);border-top:1px solid var(--tk-line);box-shadow:0 -16px 44px -14px rgb(0 0 0 / .38);transform:translateY(105%);transition:transform .34s cubic-bezier(.2,.8,.2,1);will-change:transform}',
    '.tk-sheet.in{transform:none}',
    '.tk-sheet .grab{width:36px;height:4px;border-radius:2px;background:var(--tk-line);margin:0 auto 26px}',
    '.tk-sheet .x{position:absolute;right:14px;top:12px;width:30px;height:30px;padding:0;border:0;border-radius:999px;background:var(--tk-card);color:var(--tk-mut);display:grid;place-items:center;cursor:pointer}',
    '.tk-sheet.sov{padding:0 0 calc(28px + env(safe-area-inset-bottom));overflow:hidden}',
    '.tk-sheet.sov .x{background:rgb(0 0 0 / .45);color:#fff}',
    '.tk-back{position:fixed;inset:0;z-index:9998;background:rgb(0 0 0 / .35);opacity:0;transition:opacity .3s}.tk-back.in{opacity:1}',
    '.tk-btn{display:flex;align-items:center;justify-content:center;gap:8px;width:100%;height:48px;padding:0 16px;border:0;border-radius:12px;background:var(--tk-acc);color:#fff;font:inherit;font-size:15px;font-weight:600;cursor:pointer;text-decoration:none}',
    '.tk-btn.alt{background:var(--tk-card);color:var(--tk-ink)}',
    '.tk-prev{display:flex;gap:12px;align-items:center;padding:10px;border-radius:14px;background:var(--tk-card)}',
    '.tk-prev img{width:56px;height:56px;border-radius:10px;object-fit:cover;flex:none}',
    '.tk-guard{position:fixed;inset:0;z-index:10001;background:rgb(0 0 0 / .5);display:grid;place-items:center;padding:16px}.tk-guard iframe{width:100%;max-width:420px;height:520px;border:0;border-radius:16px;background:#fff}',
    '@media (min-width:700px){.tk-sheet{left:auto;right:24px;bottom:96px;width:400px;border-radius:22px;border:1px solid var(--tk-line);padding-bottom:24px;transform:translateY(calc(100% + 40px))}.tk-sheet.sov{padding-bottom:24px}.tk-sheet .grab{visibility:hidden;margin-bottom:22px}.tk-sheet.sov .grabw{display:none}.tk-sheet.mid{left:50%;right:auto;bottom:50%;transform:translate(-50%,calc(50% + 40px));opacity:0;transition:transform .3s,opacity .3s}.tk-sheet.mid.in{transform:translate(-50%,50%);opacity:1}}',
    '@media (prefers-reduced-motion:reduce){.tk-sheet,.tk-back{transition:none}}'
  ].join('');
  var st = doc.createElement('style'); st.id = 'tk-grow-css'; st.textContent = css; doc.head.appendChild(st);

  /* ---------- pieces ---------- */
  var X = '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.4" stroke-linecap="round" aria-hidden="true"><path d="M6 6l12 12M18 6 6 18"/></svg>';
  var SHARE_IC = '<svg width="17" height="17" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M12 15V3M7 8l5-5 5 5M5 13v6a2 2 0 0 0 2 2h10a2 2 0 0 0 2-2v-6"/></svg>';
  var COPY_IC = '<svg width="17" height="17" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><rect x="9" y="9" width="12" height="12" rx="2"/><path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1"/></svg>';
  var AV = CDN + 'tk-david.jpg';
  var FACES = '<span class="faces">' + ['maya', 'merve-goulding', 'brian-muriithi', 'koko'].map(function (n) { return '<img src="' + CDN + 'tk-reader-' + n + '.jpg" alt="" width="24" height="24" loading="lazy">'; }).join('') + '</span>';
  function esc(t) { return String(t).replace(/[&<>"]/g, function (c) { return { '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;' }[c]; }); }
  function form(id, label, cls) {
    return '<form class="combo ' + (cls || '') + '" action="https://app.kit.com/forms/' + id + '/subscriptions" method="post" data-tk-form="' + id + '">' +
      '<input type="email" name="email_address" placeholder="Your email" autocomplete="email" inputmode="email" required aria-label="Email address">' +
      '<button type="submit">' + label + '</button></form><div class="tk-err" role="alert"></div>';
  }

  /* ---------- forms: submit to Kit, keep the reader on the site ---------- */
  function guard(url, done) {
    var w = doc.createElement('div'); w.className = 'tk-guard'; w.innerHTML = '<iframe title="Confirm you are human" src="' + esc(url) + '"></iframe>';
    function fin(ok) { window.removeEventListener('message', on); w.remove(); done(ok); }
    function on(e) { if (e.data && e.data.name === 'ckjs:guard:confirmed') fin(true); }
    window.addEventListener('message', on);
    w.addEventListener('click', function (e) { if (e.target === w) fin(false); });
    body.appendChild(w);
  }
  function wire(f) {
    if (f.__tk) return; f.__tk = 1;
    f.addEventListener('submit', function (ev) {
      ev.preventDefault();
      var btn = f.querySelector('button'), err = f.nextElementSibling && f.nextElementSibling.classList.contains('tk-err') ? f.nextElementSibling : null;
      var id = f.getAttribute('data-tk-form'), fd = new FormData(f);
      if (ref) fd.set('fields[tk_referred_by]', ref);
      fd.append('referrer', doc.referrer); fd.append('host', location.href.split('?')[0]); fd.append('ckjs_version', '6');
      if (err) err.textContent = '';
      btn.disabled = true;
      function ok() {
        set('tk_sub', 1); isSub = true;
        try { f.dispatchEvent(new CustomEvent('tk:subscribed', { bubbles: true, detail: { form: id } })); } catch (e) {}
        if (id === FORM_SOV) {
          f.outerHTML = '<div class="tk-done"><b>Chapter one is on its way.</b> Check your inbox in a minute.</div>';
        } else if (isJoin && window.__tkJoinWelcome) {
          window.__tkJoinWelcome();
        } else {
          location.href = '/join/?welcome=1';
        }
      }
      function fail(msg) { btn.disabled = false; if (err) err.textContent = msg || 'That did not go through. Please try again.'; }
      fetch(f.action, { method: 'POST', body: fd, headers: { Accept: 'application/json', 'X-CKJS-Version': '6' } })
        .then(function (r) { if (!r.ok) throw new Error('http'); return r.json(); })
        .then(function (j) {
          if (j.status === 'success') ok();
          else if (j.status === 'quarantined' && j.url) guard(j.url, function (passed) { passed ? ok() : fail('Please confirm the check to subscribe.'); });
          else fail(j.errors && j.errors.messages && j.errors.messages[0]);
        })
        .catch(function () { try { f.__tk = 0; HTMLFormElement.prototype.submit.call(f); } catch (e) { fail(); } });
    });
  }
  function wireAll(root) { (root || doc).querySelectorAll('form[data-tk-form]').forEach(wire); }
  window.__tkGrow.wire = wireAll;

  /* ---------- sharing ---------- */
  function canonical() {
    var c = doc.querySelector('link[rel=canonical]');
    return ((c && c.href) || (location.origin + location.pathname)).split('?')[0].split('#')[0];
  }
  function shareTarget(code) {
    if (!code) return isPost ? canonical() : 'https://theknowledge.io/';
    return isPost ? canonical() + '?ref=' + code : 'https://theknowledge.io/r/' + code;
  }
  function copy(text, btn) {
    function done() { if (btn) { var o = btn.innerHTML; btn.innerHTML = 'Link copied'; setTimeout(function () { btn.innerHTML = o; }, 2200); } }
    if (navigator.clipboard && navigator.clipboard.writeText) navigator.clipboard.writeText(text).then(done, legacy); else legacy();
    function legacy() { var t = doc.createElement('textarea'); t.value = text; t.style.cssText = 'position:fixed;opacity:0'; body.appendChild(t); t.select(); try { doc.execCommand('copy'); done(); } catch (e) {} t.remove(); }
  }
  function doShare(url, btn) {
    if (navigator.share) navigator.share({ text: MSG, url: url }).catch(function () {});
    else copy(url, btn);
  }
  window.__tkGrow.share = function (btn) { doShare(shareTarget(share), btn); };

  /* ---------- sheets ---------- */
  var sheetOpen = false;
  function openSheet(html, cls, opts) {
    if (sheetOpen) return null;
    sheetOpen = true; opts = opts || {};
    if (opts.mark) set('tk_sheet', { t: Date.now(), k: opts.mark });
    var el = doc.createElement('div'), back = null;
    el.className = 'tkx tk-sheet ' + (cls || ''); el.setAttribute('role', 'dialog'); el.setAttribute('aria-label', opts.label || 'The Knowledge');
    el.innerHTML = html;
    if (opts.backdrop) { back = doc.createElement('div'); back.className = 'tk-back'; body.appendChild(back); back.addEventListener('click', close); }
    body.appendChild(el); wireAll(el);
    requestAnimationFrame(function () { requestAnimationFrame(function () { el.classList.add('in'); if (back) back.classList.add('in'); }); });
    function close() {
      if (!sheetOpen) return; sheetOpen = false;
      el.classList.remove('in'); if (back) back.classList.remove('in');
      doc.removeEventListener('keydown', key);
      setTimeout(function () { el.remove(); if (back) back.remove(); }, 380);
      if (opts.onClose) opts.onClose();
    }
    function key(e) { if (e.key === 'Escape') close(); }
    doc.addEventListener('keydown', key);
    var x = el.querySelector('.x'); if (x) x.addEventListener('click', close);
    el.close = close;
    return el;
  }
  var GRAB = '<div class="grab"></div>', XB = '<button type="button" class="x" aria-label="Close">' + X + '</button>';
  function subSheet() {
    return openSheet(GRAB + XB +
      '<div style="display:flex;gap:14px;align-items:center"><img class="av" src="' + AV + '" alt="David Elikwu" width="56" height="56"><div style="flex:1;min-width:0;padding-right:24px"><div class="serif" style="font-size:21px;font-weight:600;line-height:1.2">Get an essay like this every Thursday</div></div></div>' +
      '<div class="mut" style="font-size:14.5px;line-height:1.45;margin-top:12px">I write The Knowledge for 40,000+ people who want to think deeper and work smarter.</div>' +
      '<div style="margin-top:16px">' + form(FORM_SUB, 'Subscribe', 'f2') + '</div>' +
      '<div class="mut" style="display:flex;align-items:center;gap:10px;margin-top:14px;font-size:13px">' + FACES + '<span><span class="stars">★★★★★</span> rated 5.0 by readers</span></div>',
      '', { label: 'Subscribe to The Knowledge', mark: 'sub' });
  }
  function sovSheet() {
    return openSheet(
      '<div style="position:relative;height:118px"><img src="' + CDN + 'tk-sovereign-life.jpg" alt="" style="width:100%;height:100%;object-fit:cover;object-position:50% 30%"><div style="position:absolute;inset:0;background:linear-gradient(180deg,rgb(0 0 0 / .15),rgb(0 0 0 / .45))"></div><div class="grabw" style="position:absolute;left:50%;top:10px;width:36px;height:4px;margin-left:-18px;border-radius:2px;background:rgb(255 255 255 / .6)"></div>' + XB + '</div>' +
      '<div style="padding:0 20px;display:flex;gap:16px;align-items:flex-end;margin-top:-46px;position:relative"><img src="' + CDN + 'tk-sovereign-cover.png" alt="Sovereign, the book" width="76" height="114" style="width:76px;height:114px;flex:none;filter:drop-shadow(0 8px 14px rgb(0 0 0 / .4))"><div style="flex:1;min-width:0;padding-bottom:2px"><div class="serif" style="font-size:22px;font-weight:600;line-height:1.15">Sovereign</div><div class="mut" style="font-size:14px;line-height:1.35;margin-top:2px;text-wrap:balance">The owner’s manual for a remarkable life</div></div></div>' +
      '<div style="padding:0 20px"><div style="display:flex;gap:10px;align-items:baseline;margin-top:16px"><span class="stars">★★★★★</span><span class="serif" style="font-size:15.5px;line-height:1.4;font-style:italic;text-wrap:balance">“A manual for life. Modern stoicism at its best.”</span></div>' +
      '<div style="margin-top:16px">' + form(FORM_SOV, 'Read chapter one', 'f2') + '</div></div>',
      'sov', { label: 'Sovereign: read chapter one', mark: 'sov' });
  }
  function sharerSheet(copyFirst) {
    var url = shareTarget(share), native = !!navigator.share && !copyFirst;
    var img = isPost ? ((doc.querySelector('meta[property="og:image"]') || {}).content || CDN + 'tk-join-cafe.jpg') : CDN + 'tk-join-cafe.jpg';
    var title = isPost ? ((doc.querySelector('meta[property="og:title"]') || {}).content || doc.title) : 'The Knowledge';
    var sub = isPost ? 'The Knowledge' : 'One essay every Thursday';
    var el = openSheet(GRAB + XB +
      '<div class="serif" style="font-size:21px;font-weight:600;line-height:1.2;padding-right:30px">Send this to a friend</div>' +
      '<div class="tk-prev" style="margin-top:14px"><img src="' + esc(img) + '" alt=""><div style="min-width:0;line-height:1.3"><div style="font-size:14.5px;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap">' + esc(title) + '</div><div class="mut" style="font-size:13px">' + sub + '</div><div class="mut" style="font-size:12px;opacity:.75;margin-top:2px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap">' + esc(url.replace('https://', '')) + '</div></div></div>' +
      '<button type="button" class="tk-btn" data-act="' + (native ? 'share' : 'copy') + '" style="margin-top:14px">' + (native ? SHARE_IC + 'Share' : COPY_IC + 'Copy link') + '</button>' +
      '<div class="mut" style="font-size:13px;line-height:1.4;margin-top:12px;text-align:center">When they subscribe, it counts towards your rewards.</div>',
      'mid', { label: 'Share with a friend', backdrop: true });
    if (!el) return;
    el.querySelector('.tk-btn').addEventListener('click', function () { native ? doShare(url, this) : copy(url, this); });
  }

  /* ---------- on-page pieces ---------- */
  function midCard() {
    var kids = [].filter.call(article.children, function (n) { return n.tagName === 'P' && n.textContent.trim().length > 60; });
    if (kids.length < 8) return;
    var at = kids[Math.floor(kids.length * 0.45)];
    var nx = at.nextElementSibling; if (nx && nx.tagName !== 'P') return;
    var d = doc.createElement('div'); d.className = 'tkx tk-card not-prose';
    d.innerHTML = '<div style="display:flex;gap:12px;align-items:center"><img class="av" src="' + AV + '" alt="David Elikwu" width="48" height="48" loading="lazy"><div style="line-height:1.3"><div class="serif" style="font-size:18px;font-weight:600">Enjoying this one?</div><div class="mut" style="font-size:14px">I send an essay like it every Thursday.</div></div></div>' +
      '<div style="margin-top:14px">' + form(FORM_SUB, 'Subscribe') + '</div>' +
      '<div class="mut" style="display:flex;align-items:center;gap:8px;margin-top:12px;font-size:12.5px">' + FACES + '<span style="margin-left:4px">Join 40,000+ readers <span class="stars" style="margin-left:4px">★★★★★</span></span></div>';
    at.parentNode.insertBefore(d, at.nextSibling); wireAll(d);
  }
  function welcomeNote(who) {
    var d = doc.createElement('div'); d.className = 'tkx tk-note not-prose';
    d.innerHTML = '<div style="display:flex;align-items:center;gap:12px"><img class="av" src="' + AV + '" alt="David Elikwu" width="48" height="48"><div style="flex:1;min-width:0;line-height:1.35"><div style="font-size:15.5px"><b>' + esc(who) + '</b> thought you’d like this.</div><div class="mut" style="font-size:14px;margin-top:1px">It’s from my weekly newsletter.</div></div></div>' +
      '<div style="margin-top:14px">' + form(FORM_SUB, 'Subscribe', 'onbg') + '</div>' +
      '<div class="mut" style="font-size:12.5px;margin-top:10px">One essay every Thursday. Join 40,000+ readers.</div>';
    var h = doc.querySelector('main h1'), at = h ? (h.previousElementSibling || h) : null;
    if (at && at.parentNode) at.parentNode.insertBefore(d, at); else article.insertBefore(d, article.firstChild);
    wireAll(d);
  }
  function friendName(code, cb) {
    var done = false, t = setTimeout(function () { fin('A friend'); }, 1200);
    function fin(n) { if (done) return; done = true; clearTimeout(t); cb(n); }
    try {
      fetch(API + '/referrals/name?ref=' + encodeURIComponent(code), { credentials: 'omit' })
        .then(function (r) { return r.ok ? r.json() : {}; })
        .then(function (j) { var n = j && typeof j.name === 'string' ? j.name.trim() : ''; fin(/^[\p{L}][\p{L}' -]{0,23}$/u.test(n) ? n : 'A friend'); })
        .catch(function () { fin('A friend'); });
    } catch (e) { fin('A friend'); }
  }
  window.__tkGrow.friendName = friendName;

  /* ---------- run ---------- */
  function cleanUrl() {
    try { ['share', 'copy', 'via'].forEach(function (k) { qs.delete(k); }); var q = qs.toString(); history.replaceState(null, '', location.pathname + (q ? '?' + q : '') + location.hash); } catch (e) {}
  }
  function onScroll(frac, fn) {
    function chk() {
      var r = article.getBoundingClientRect();
      if (r.height && (innerHeight - r.top) / r.height >= frac) { removeEventListener('scroll', chk); fn(); }
    }
    addEventListener('scroll', chk, { passive: true }); chk();
  }
  function quiet() { var a = doc.activeElement; return !(a && /INPUT|TEXTAREA|SELECT/.test(a.tagName)); }

  function run() {
    wireAll();
    if (share) {
      var via = qs.get('via'), wantCopy = qs.get('copy') === '1', target = shareTarget(share);
      cleanUrl();
      if (via === 'sms') location.href = 'sms:?&body=' + encodeURIComponent(MSG + ' ' + target);
      else if (via === 'email') location.href = 'mailto:?subject=' + encodeURIComponent("Thought you'd like this") + '&body=' + encodeURIComponent(MSG + ':\n\n' + target);
      setTimeout(function () { sharerSheet(wantCopy); }, via ? 900 : 350);
      return;
    }
    if (!isPost) return;
    if (!isSub && refFromUrl) {
      friendName(ref, welcomeNote);
    } else if (!isSub) {
      midCard();
    }
    var last = get('tk_sheet') || {}, age = Date.now() - (last.t || 0);
    if (!isSub) {
      if (age > 14 * DAY) onScroll(refFromUrl ? 0.7 : 0.55, function () { if (!isSub && quiet()) subSheet(); });
    } else if (age > (last.k === 'sov' ? 30 : 3) * DAY && !get('tk_sov')) {
      onScroll(0.75, function () { if (quiet()) { var s = sovSheet(); if (s) s.addEventListener('tk:subscribed', function () { set('tk_sov', 1); }); } });
    }
  }
  if (doc.readyState === 'loading') doc.addEventListener('DOMContentLoaded', run); else run();
})();