(() => {
  const hero = document.querySelector('.dbc-particle-hero#home');
  if (!hero) return;

  const reducedMotion = window.matchMedia
    && window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  const compactViewport = window.matchMedia
    && window.matchMedia('(max-width: 760px)').matches;
  const dbcMessageDelay = compactViewport ? 360 : 420;
  const completionFallbackDelay = compactViewport ? 4600 : 5600;

  let dbcMessageTimer = null;
  let completionFallbackTimer = null;

  hero.classList.add('is-v283-motion-active');
  hero.dataset.copyStage = 'waiting';

  const revealDbcMessage = () => {
    if (!hero.classList.contains('is-dbc-message-ready')) {
      hero.classList.add('is-dbc-message-ready');
    }
    if (!hero.classList.contains('is-bioten-phase-ready')) {
      hero.dataset.copyStage = 'dbc';
    }
  };

  const revealBiotenPhase = () => {
    revealDbcMessage();
    if (!hero.classList.contains('is-bioten-phase-ready')) {
      hero.classList.add('is-bioten-phase-ready');
    }
    if (!hero.classList.contains('is-bioten-product-ready')) {
      hero.dataset.copyStage = 'bioten';
    }
  };

  const markComplete = (fallback = false) => {
    revealBiotenPhase();
    if (!hero.classList.contains('is-bioten-product-ready')) {
      hero.classList.add('is-bioten-product-ready');
    }
    hero.dataset.copyStage = fallback ? 'fallback-complete' : 'complete';
    if (completionFallbackTimer) {
      window.clearTimeout(completionFallbackTimer);
      completionFallbackTimer = null;
    }
  };

  const syncParticleState = () => {
    if (hero.dataset.particleMode === 'bioten') {
      revealBiotenPhase();
    }
    if (
      hero.classList.contains('is-bioten-product-ready')
      && hero.dataset.copyStage !== 'complete'
      && hero.dataset.copyStage !== 'fallback-complete'
    ) {
      markComplete(false);
    }
  };

  if (reducedMotion || hero.classList.contains('is-reduced-motion')) {
    markComplete(false);
    return;
  }

  dbcMessageTimer = window.setTimeout(revealDbcMessage, dbcMessageDelay);
  completionFallbackTimer = window.setTimeout(
    () => markComplete(true),
    completionFallbackDelay
  );

  const observer = new MutationObserver(syncParticleState);
  observer.observe(hero, {
    attributes: true,
    attributeFilter: ['class', 'data-particle-mode']
  });

  syncParticleState();

  window.addEventListener('pageshow', syncParticleState);
})();