/* 兜爸心选官网 · 轻交互（无依赖） */
(function () {
  document.documentElement.classList.add('js');

  var nav = document.getElementById('nav');
  var onScroll = function () {
    if (!nav) return;
    nav.classList.toggle('is-stuck', window.scrollY > 24);
  };
  onScroll();
  window.addEventListener('scroll', onScroll, { passive: true });

  var items = document.querySelectorAll('[data-reveal]');
  if ('IntersectionObserver' in window) {
    var io = new IntersectionObserver(function (entries) {
      entries.forEach(function (e) {
        if (e.isIntersecting) {
          e.target.classList.add('is-in');
          io.unobserve(e.target);
        }
      });
    }, { rootMargin: '0px 0px -12% 0px', threshold: 0.12 });
    items.forEach(function (el) { io.observe(el); });
  } else {
    items.forEach(function (el) { el.classList.add('is-in'); });
  }

  // 同一时间只展开一个 FAQ
  var qas = document.querySelectorAll('.qa');
  qas.forEach(function (d) {
    d.addEventListener('toggle', function () {
      if (!d.open) return;
      qas.forEach(function (o) { if (o !== d) o.open = false; });
    });
  });

  // 首屏手机屏：6 张界面截图自动轮换（悬停暂停 / 切后台暂停 / 尊重"减少动效"）
  (function () {
    var box = document.getElementById('heroSlides');
    if (!box) return;
    var slides = Array.prototype.slice.call(box.querySelectorAll('.hs-slide'));
    if (slides.length < 2) return;
    var reduce = window.matchMedia('(prefers-reduced-motion: reduce)');
    var idx = 0, timer = null, hover = false;

    function show(n) {
      slides[idx].classList.remove('is-on');
      idx = (n + slides.length) % slides.length;
      slides[idx].classList.add('is-on');
    }
    function stop() { if (timer) { clearInterval(timer); timer = null; } }
    function start() {
      stop();
      if (reduce.matches) return;
      timer = setInterval(function () {
        if (hover || document.hidden) return;
        show(idx + 1);
      }, 4200);
    }
    box.addEventListener('mouseenter', function () { hover = true; });
    box.addEventListener('mouseleave', function () { hover = false; });
    document.addEventListener('visibilitychange', function () { if (!document.hidden) start(); });
    if (reduce.addEventListener) reduce.addEventListener('change', start);
    start();
  })();

  // 外链统一安全属性
  document.querySelectorAll('a[href^="http"]').forEach(function (a) {
    a.rel = 'noopener';
  });
})();