(function () {
  'use strict';

  if (window.__DBC_SITE_V282__) return;
  window.__DBC_SITE_V282__ = true;

  const html = document.documentElement;
  const body = document.body;

  function markRelease() {
    const release = body.dataset.dbcRelease || html.dataset.dbcRelease || 'v3.0.0';
    html.dataset.dbcRelease = release;
    body.dataset.dbcRelease = release;
    body.classList.add('v282-enhanced');
    const footer = document.querySelector('footer.site-footer, footer.v260-footer');
    if (footer) footer.dataset.dbcRelease = release;
  }

  function stabilizeMeasuredContent() {
    if (body.classList.contains('home-v282')) return;
    document.querySelectorAll('[data-v270-reveal], [data-v280-reveal]').forEach(function (element) {
      element.classList.add('is-v270-visible', 'is-v280-visible');
    });
  }

  function wrapTechnicalTables() {
    document.querySelectorAll('main table').forEach(function (table) {
      const parent = table.parentElement;
      if (!parent || parent.classList.contains('v282-table-wrap')) return;
      if (/(?:table-wrap|table-scroll|table-container|overflow)/i.test(parent.className || '')) return;

      const wrapper = document.createElement('div');
      wrapper.className = 'v282-table-wrap';
      wrapper.tabIndex = 0;
      wrapper.setAttribute('role', 'region');
      const section = table.closest('section, article');
      const heading = section && section.querySelector('h2, h3');
      wrapper.setAttribute('aria-label', heading ? `${heading.textContent.trim()}表格` : '技术信息表格');
      parent.insertBefore(wrapper, table);
      wrapper.appendChild(table);
    });
  }

  function centerCurrentPath() {
    if (!window.matchMedia('(max-width: 760px)').matches) return;
    document.querySelectorAll('.v281-path ol').forEach(function (list) {
      const current = list.querySelector('[data-v281-current]');
      if (!current) return;
      const target = current.offsetLeft - Math.max(0, (list.clientWidth - current.offsetWidth) / 2);
      list.scrollLeft = Math.max(0, target);
    });
  }

  function markScrollableNavigation() {
    document.querySelectorAll('.v270-context__links, .about-anchor-nav, .formal-page-nav__inner, .v245-local-nav__inner, .bioten-product-nav, .knowledge-anchor-nav').forEach(function (nav) {
      if (nav.scrollWidth > nav.clientWidth + 2) nav.dataset.v282Scrollable = 'true';
      else nav.removeAttribute('data-v282-scrollable');
    });
  }

  function markFilePreviewForms() {
    if (window.location.protocol !== 'file:') return;
    document.querySelectorAll('form[action*=".php"], form[action^="/api/"]').forEach(function (form, index) {
      if (form.querySelector('.v300-file-preview-note')) return;
      const note = document.createElement('p');
      note.className = 'v300-file-preview-note';
      note.id = 'v300-file-preview-note-' + (index + 1);
      note.textContent = '本地 HTML 预览模式：页面内容可以浏览，表单提交需在已配置 PHP 的网站环境中完成。';
      form.appendChild(note);
      const submit = form.querySelector('button[type="submit"], input[type="submit"]');
      if (submit) submit.setAttribute('aria-describedby', note.id);
      form.addEventListener('submit', function (event) {
        event.preventDefault();
        note.dataset.active = 'true';
        note.setAttribute('role', 'status');
      });
    });
  }

  markRelease();
  stabilizeMeasuredContent();
  wrapTechnicalTables();
  centerCurrentPath();
  markScrollableNavigation();
  markFilePreviewForms();

  let resizeFrame = 0;
  window.addEventListener('resize', function () {
    window.cancelAnimationFrame(resizeFrame);
    resizeFrame = window.requestAnimationFrame(function () {
      centerCurrentPath();
      markScrollableNavigation();
    });
  }, { passive: true });
})();