(function () {
  'use strict';

  var root = document.documentElement;
  var body = document.body;
  if (!body || root.dataset.v7318PackagingGovernance !== 'packaging-family-r1') return;
  if (window.__DBC_PACKAGING_V7318_GOVERNANCE__) return;
  window.__DBC_PACKAGING_V7318_GOVERNANCE__ = true;

  var pendingReadingAnchor = null;
  var restoreToken = 0;
  var lastLanguage = '';

  function language() {
    return root.dataset.lang === 'en' || root.lang === 'en' ? 'en' : 'zh';
  }

  function updateLanguageUrl(next) {
    try {
      var url = new URL(window.location.href);
      if (url.searchParams.get('lang') === next) return;
      url.searchParams.set('lang', next);
      window.history.replaceState(window.history.state, '', url.pathname + url.search + url.hash);
    } catch (error) {
      /* Local file previews and locked-down browsers may not expose History API. */
    }
  }

  function semanticReadingAnchor() {
    var header = document.querySelector('.site-header');
    var context = document.querySelector('.bp7140-context');
    var threshold = (header ? header.getBoundingClientRect().height : 0)
      + (context ? Math.min(context.getBoundingClientRect().height, 58) : 0)
      + 28;
    var candidates = Array.prototype.filter.call(
      document.querySelectorAll('main section[id], main article[id], main [data-v7318-reading-anchor][id]'),
      function (element) {
        var rect = element.getBoundingClientRect();
        return rect.height > 0 && rect.bottom > threshold;
      }
    );
    var selected = null;
    candidates.forEach(function (element) {
      var top = element.getBoundingClientRect().top;
      if (top <= threshold + 24) selected = element;
    });
    if (!selected) selected = candidates[0] || document.getElementById('main-content');
    if (!selected || !selected.id) return null;
    return { id: selected.id, top: selected.getBoundingClientRect().top };
  }

  function restoreReadingAnchor(anchor) {
    if (!anchor) return;
    var token = ++restoreToken;
    window.requestAnimationFrame(function () {
      window.requestAnimationFrame(function () {
        if (token !== restoreToken) return;
        var target = document.getElementById(anchor.id);
        if (!target) return;
        var delta = target.getBoundingClientRect().top - anchor.top;
        if (Math.abs(delta) > 1) window.scrollBy(0, delta);
      });
    });
  }

  function contextualAlt(image, next) {
    if (!image.dataset.v7318AltZh) image.dataset.v7318AltZh = image.getAttribute('alt') || '';
    if (next !== 'en') {
      image.alt = image.dataset.altZh || image.dataset.altCn || image.dataset.v7318AltZh;
      return;
    }
    if (image.dataset.altEn) {
      image.alt = image.dataset.altEn;
      return;
    }
    if (image.closest('.site-header, footer')) {
      image.alt = image.dataset.altCn || image.dataset.altZh || image.dataset.v7318AltZh;
      return;
    }
    var card = image.closest('article, figure, a, section');
    var labelNode = card && card.querySelector('[data-en], [data-html-en], h2, h3, strong');
    var label = labelNode && (labelNode.dataset.en || labelNode.textContent || '').trim();
    image.alt = label
      ? label.replace(/\s+/g, ' ') + ' · BIOTEN Packaging visual'
      : 'BIOTEN Packaging engineering visual';
  }

  function syncBilingualAttributes(next) {
    document.querySelectorAll('.site-header img, main img, footer img').forEach(function (image) {
      contextualAlt(image, next);
    });
    document.querySelectorAll('[data-aria-zh], [data-aria-cn]').forEach(function (element) {
      if (!element.dataset.v7318AriaZh) {
        element.dataset.v7318AriaZh = element.dataset.ariaZh || element.dataset.ariaCn || element.getAttribute('aria-label') || '';
      }
      var value = next === 'en'
        ? element.dataset.ariaEn
        : (element.dataset.ariaZh || element.dataset.ariaCn);
      if (value) element.setAttribute('aria-label', value);
    });

    var ariaDictionary = {
      '世界杯竞猜官网首页': 'DBC homepage',
      '博碳包装主页': 'BIOTEN Packaging homepage',
      '主导航': 'Main navigation',
      '展开导航': 'Expanded navigation',
      '快捷入口': 'Quick links',
      '发布序号': 'Release number',
      '新应用发布动态': 'New application release stream',
      '暂停自动播放技术发布': 'Pause automatic release playback',
      '恢复自动播放技术发布': 'Resume automatic release playback',
      '文章目录': 'Article contents'
    };
    document.querySelectorAll('[aria-label]').forEach(function (element) {
      if (!element.dataset.v7318AriaZh) element.dataset.v7318AriaZh = element.getAttribute('aria-label') || '';
      var source = element.dataset.v7318AriaZh;
      if (next === 'en' && ariaDictionary[source]) element.setAttribute('aria-label', ariaDictionary[source]);
      if (next !== 'en' && source) element.setAttribute('aria-label', source);
    });
  }

  function syncHiddenState(element) {
    var hidden = element.hidden || element.getAttribute('aria-hidden') === 'true';
    if (hidden) element.setAttribute('inert', '');
    else element.removeAttribute('inert');
    if ('inert' in element) element.inert = hidden;
  }

  function syncNavigationInert() {
    document.querySelectorAll('.dbc-desktop-mega, .dbc-nav-overlay, .dbc-nav-view').forEach(syncHiddenState);
  }

  function governSampleLanguageBoundary() {
    if (body.dataset.v7318PackagingPage !== 'sample') return;
    var note = document.querySelector('main > .v770-language-boundary');
    var hero = document.querySelector('main > .request-hero');
    if (note && hero && note.previousElementSibling !== hero) hero.insertAdjacentElement('afterend', note);
  }

  function centerCurrentContextLink() {
    var current = document.querySelector('.bp7140-context a[aria-current="page"], .bp7140-context a.is-active');
    var track = current && current.closest('.bp7140-context__inner');
    if (!current || !track) return;
    var left = current.offsetLeft - (track.clientWidth - current.offsetWidth) / 2;
    if (typeof track.scrollTo === 'function') track.scrollTo({ left: Math.max(0, left), behavior: 'auto' });
    else track.scrollLeft = Math.max(0, left);
  }

  function applyRuntimeLanguage(next, shouldRestore) {
    syncBilingualAttributes(next);
    updateLanguageUrl(next);
    centerCurrentContextLink();
    if (shouldRestore && pendingReadingAnchor) {
      restoreReadingAnchor(pendingReadingAnchor);
      pendingReadingAnchor = null;
    }
    lastLanguage = next;
  }

  document.addEventListener('click', function (event) {
    var languageButton = event.target.closest('[data-language-toggle]');
    if (languageButton && !languageButton.hasAttribute('data-language-home-fallback')) {
      pendingReadingAnchor = semanticReadingAnchor();
      return;
    }
    var skip = event.target.closest('.skip-link[href="#main-content"]');
    if (!skip) return;
    var main = document.getElementById('main-content');
    if (!main) return;
    event.preventDefault();
    if (!main.hasAttribute('tabindex')) main.setAttribute('tabindex', '-1');
    main.focus({ preventScroll: true });
    main.scrollIntoView({ block: 'start', behavior: 'auto' });
    try { window.history.replaceState(window.history.state, '', '#main-content'); } catch (error) { /* no-op */ }
  }, true);

  document.addEventListener('keydown', function (event) {
    if (event.key !== 'Escape') return;
    var trigger = document.querySelector('[data-dbc-nav-open]');
    if (!trigger || trigger.getAttribute('aria-expanded') !== 'true') return;
    window.setTimeout(function () {
      if (trigger.getAttribute('aria-expanded') !== 'true') return;
      var close = document.querySelector('.dbc-nav-close');
      if (close) close.click();
    }, 0);
  }, true);

  document.addEventListener('dbc:navigation-open', function () {
    var attempts = 0;
    function focusVisibleCloseButton() {
      var trigger = document.querySelector('[data-dbc-nav-open]');
      var close = document.querySelector('.dbc-nav-close');
      if (!trigger || trigger.getAttribute('aria-expanded') !== 'true' || !close) return;
      if (close.offsetParent !== null && window.getComputedStyle(close).visibility === 'visible') {
        close.focus({ preventScroll: true });
        return;
      }
      attempts += 1;
      if (attempts < 8) window.requestAnimationFrame(focusVisibleCloseButton);
    }
    window.requestAnimationFrame(focusVisibleCloseButton);
  });

  document.addEventListener('dbc:languagechange', function (event) {
    var next = event.detail && event.detail.language === 'en' ? 'en' : 'zh';
    applyRuntimeLanguage(next, true);
  });

  var languageObserver = new MutationObserver(function () {
    var next = language();
    if (next !== lastLanguage) applyRuntimeLanguage(next, Boolean(pendingReadingAnchor));
  });
  languageObserver.observe(root, { attributes: true, attributeFilter: ['data-lang', 'lang'] });

  var navigationObserver = new MutationObserver(function (records) {
    records.forEach(function (record) {
      var target = record.target;
      if (target.matches && target.matches('.dbc-desktop-mega, .dbc-nav-overlay, .dbc-nav-view')) syncHiddenState(target);
      if (target.matches && target.matches('.bp7140-context a')) centerCurrentContextLink();
    });
  });
  navigationObserver.observe(document.documentElement, {
    subtree: true,
    attributes: true,
    attributeFilter: ['aria-hidden', 'aria-current', 'class', 'hidden']
  });

  document.querySelectorAll('[data-bp7151-ticker-track][aria-live]').forEach(function (track) {
    track.setAttribute('aria-live', 'off');
  });
  governSampleLanguageBoundary();
  window.setTimeout(governSampleLanguageBoundary, 250);
  syncNavigationInert();
  applyRuntimeLanguage(language(), false);
  root.dataset.v7318PackagingRuntime = 'ready';
}());