/* Than Vu - muc luc tu dong cho trang bai/san pham (v1, 16/10/2026): neu noi dung co >=3 H2 ma chua co muc luc thi tao khung "Mục lục" (dat sau khoi "Trả lời nhanh" hoac sau doan dau). tv-chuanhoa tu trinh bay lai thanh "Trong bài này". */
(function(){
function run(){
  if(!document.querySelector('.product-essential'))return;
  var c=document.querySelector('.tab_content')||document.querySelector('.des');
  if(!c||document.getElementById('tvtoc')||document.getElementById('tvtoc3')||c.getAttribute('data-tvtocauto'))return;
  var has=[].some.call(c.querySelectorAll('div,nav'),function(e){var f=e.firstElementChild;return f&&/^\s*(Nội dung chính|Mục lục)/i.test(f.textContent||'')});
  if(has)return;
  var hs=[].filter.call(c.querySelectorAll('h2'),function(h){var t=(h.textContent||'').trim();return t.length>2&&!/liên quan|cùng chuyên mục/i.test(t)});
  if(hs.length<3)return;
  c.setAttribute('data-tvtocauto','1');
  var box=document.createElement('div'),p=document.createElement('p'),ul=document.createElement('ul');
  p.textContent='Mục lục';
  hs.forEach(function(h,i){if(!h.id)h.id='muc-'+(i+1);var li=document.createElement('li'),a=document.createElement('a');a.href='#'+h.id;a.textContent=(h.textContent||'').replace(/\s+/g,' ').trim();li.appendChild(a);ul.appendChild(li)});
  box.appendChild(p);box.appendChild(ul);
  var qa=null;[].some.call(c.querySelectorAll('div'),function(d){if(d.firstElementChild&&(d.firstElementChild.textContent||'').trim()==='Trả lời nhanh'){qa=d;return true}return false});
  var ref=qa||c.querySelector('p');
  if(ref&&ref.parentNode)ref.parentNode.insertBefore(box,ref.nextSibling);else c.insertBefore(box,c.firstChild);
}
if(document.readyState==='loading')document.addEventListener('DOMContentLoaded',run);else run();
})();