(function () {
  var HIDE_AT_ROOT = new Set(['content', 'excels', 'excels_html', 'pdfs', 'words', 'words_html']);

  function isRootFilesPath(path) {
    var p = (path || '').replace(/\/+$/, '');
    return p === '' || p === '/files';
  }

  function textOf(el) {
    var n = el.querySelector && el.querySelector('.name');
    var t = n ? (n.textContent || '') : (el.textContent || '');
    return t.trim();
  }

  function hideDefaultFoldersAtRoot() {
    if (!isRootFilesPath(location.pathname)) return;

    var items = document.querySelectorAll('#listing .item');
    items.forEach(function (item) {
      var name = textOf(item);
      if (!name || !HIDE_AT_ROOT.has(name)) return;

      // hide item card/row without affecting backend data
      item.style.display = 'none';
      item.setAttribute('data-fb-hidden-default', '1');
    });
  }

  function apply() {
    hideDefaultFoldersAtRoot();
  }

  var ob = new MutationObserver(function () { apply(); });
  ob.observe(document.documentElement, { childList: true, subtree: true });

  apply();
  setTimeout(apply, 100);
  setTimeout(apply, 400);
})();