(function () {
  var tabs = document.querySelectorAll('[data-call]');
  var select = function (id, scroll) {
    tabs.forEach(function (t) {
      var on = t.getAttribute('data-call') === id;
      t.setAttribute('aria-selected', String(on));
      var panel = document.getElementById('cal-' + t.getAttribute('data-call'));
      if (panel) { if (on) panel.removeAttribute('data-off'); else panel.setAttribute('data-off', ''); }
    });
    if (scroll) document.getElementById('schedule').scrollIntoView({ behavior: 'smooth', block: 'start' });
  };
  tabs.forEach(function (t) {
    t.addEventListener('click', function () {
      var id = t.getAttribute('data-call');
      select(id, true);
      try { history.replaceState(null, '', '#' + id); } catch (e) {}
    });
  });
  var hash = location.hash.replace('#', '');
  if (hash === 'free' || hash === 'vip') select(hash, false);
})();