(function () {
  'use strict';

  if (window.__DBC_SITE_V281__) return;
  window.__DBC_SITE_V281__ = true;

  const html = document.documentElement;
  const body = document.body;
  const reducedMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  function currentFile() {
    const value = window.location.pathname.split('/').pop();
    return value || 'index.html';
  }

  function resolvedUrl(link) {
    try {
      return new URL(link.getAttribute('href'), window.location.href);
    } catch {
      return null;
    }
  }

  function markRelease() {
    const release = body.dataset.dbcRelease || html.dataset.dbcRelease || 'v3.0.0';
    html.dataset.dbcRelease = release;
    body.dataset.dbcRelease = release;
    body.classList.add('v281-enhanced');
    const footer = document.querySelector('footer.site-footer');
    if (footer) footer.dataset.dbcRelease = release;
  }

  function markLinkSemantics() {
    const file = currentFile();
    document.querySelectorAll('a[href]').forEach(function (link) {
      const url = resolvedUrl(link);
      if (!url) return;
      const external = url.origin !== window.location.origin && url.protocol !== 'file:';
      if (external) {
        link.dataset.v281External = 'true';
        if (link.target === '_blank') {
          const rel = new Set((link.getAttribute('rel') || '').split(/\s+/).filter(Boolean));
          rel.add('noopener');
          link.setAttribute('rel', Array.from(rel).join(' '));
        }
        return;
      }

      link.dataset.v281Local = 'true';
      const targetFile = url.pathname.split('/').pop() || 'index.html';
      if (targetFile === file && !url.hash && link.closest('.footer-directory')) {
        link.setAttribute('aria-current', 'page');
      }

      const label = link.textContent.replace(/\s+/g, ' ').trim();
      if (!link.getAttribute('aria-label') && /^(?:了解更多|查看详情|进入|阅读更多|More)$/i.test(label)) {
        const container = link.closest('article, li, section, div');
        const heading = container && container.querySelector('h2, h3, strong');
        if (heading) {
          const context = heading.textContent.replace(/\s+/g, ' ').trim();
          if (context && context !== label) link.setAttribute('aria-label', `${label}：${context}`);
        }
      }
    });
  }

  function rerouteSharedFooterLoops() {
    const file = currentFile();
    const cta = document.querySelector('.formal-footer-cta');
    if (!cta) return;

    const routes = {
      'about.html': {
        match: 'about.html',
        href: 'about-brands.html',
        cn: '查看业务生态',
        en: 'View business ecosystem'
      },
      'contact.html': {
        match: 'contact.html',
        href: '#intent-options',
        cn: '选择合作方向',
        en: 'Choose a collaboration path'
      },
      'sample.html': {
        match: 'sample.html',
        href: 'contact.html#routing-rules',
        cn: '查看后续对接规则',
        en: 'View follow-up routing'
      },
      'resources.html': {
        match: 'resources.html',
        href: 'knowledge-compliance-map.html',
        cn: '查看资料使用边界',
        en: 'Review document-use boundaries'
      }
    };

    const route = routes[file];
    if (!route) return;
    const link = Array.from(cta.querySelectorAll('a[href]')).find(function (candidate) {
      return candidate.getAttribute('href').split('#')[0] === route.match;
    });
    if (!link) return;
    link.href = route.href;
    link.textContent = route.cn;
    link.dataset.navCn = route.cn;
    link.dataset.navEn = route.en;
    link.dataset.v281Rerouted = 'true';
    link.removeAttribute('aria-current');
  }

  function centreCurrentPathStep() {
    const current = document.querySelector('.v281-path [data-v281-current]');
    const list = current && current.closest('ol');
    if (!current || !list || list.scrollWidth <= list.clientWidth + 2) return;
    const left = current.offsetLeft - (list.clientWidth - current.offsetWidth) / 2;
    list.scrollTo({ left: Math.max(0, left), behavior: reducedMotion ? 'auto' : 'smooth' });
  }

  function refreshHashTarget() {
    if (!window.location.hash) return;
    let id = '';
    try { id = decodeURIComponent(window.location.hash.slice(1)); } catch { id = window.location.hash.slice(1); }
    const target = id && document.getElementById(id);
    if (!target) return;
    target.dataset.v281HashTarget = 'true';
    window.setTimeout(function () {
      target.removeAttribute('data-v281-hash-target');
    }, reducedMotion ? 40 : 900);
  }

  function hashTarget(url) {
    if (!url || !url.hash) return null;
    const targetFile = url.pathname.split('/').pop() || 'index.html';
    if (targetFile !== currentFile()) return null;
    let id = '';
    try { id = decodeURIComponent(url.hash.slice(1)); } catch { id = url.hash.slice(1); }
    return id ? document.getElementById(id) : null;
  }

  function installSamePageAnchorRouting() {
    document.addEventListener('click', function (event) {
      if (event.defaultPrevented || event.button !== 0 || event.metaKey || event.ctrlKey || event.shiftKey || event.altKey) return;
      const link = event.target.closest && event.target.closest('a[href]');
      if (!link || (link.target && link.target !== '_self') || link.hasAttribute('download')) return;
      const url = resolvedUrl(link);
      const target = hashTarget(url);
      if (!target) return;

      event.preventDefault();
      const next = `${window.location.pathname}${window.location.search}${url.hash}`;
      if (window.location.hash === url.hash) window.history.replaceState(null, '', next);
      else window.history.pushState(null, '', next);
      target.scrollIntoView({ behavior: reducedMotion ? 'auto' : 'smooth', block: 'start' });
      refreshHashTarget();
    });
  }

  function settleInitialHash() {
    if (!window.location.hash) return;
    window.addEventListener('load', function () {
      window.setTimeout(function () {
        const target = hashTarget(window.location);
        if (target) target.scrollIntoView({ behavior: 'auto', block: 'start' });
      }, 220);
    }, { once: true });
  }

  markRelease();
  rerouteSharedFooterLoops();
  markLinkSemantics();
  centreCurrentPathStep();
  refreshHashTarget();
  installSamePageAnchorRouting();
  settleInitialHash();
  window.addEventListener('hashchange', refreshHashTarget, { passive: true });
})();