/* Keep the public navigation readable while content passes beneath it. */
(function () {
  'use strict';
  var root = document.documentElement;
  var pending = false;

  function update() {
    root.classList.toggle('nhc-nav-scrolled', window.scrollY > 40);
    pending = false;
  }

  function onScroll() {
    if (!pending) {
      pending = true;
      window.requestAnimationFrame(update);
    }
  }

  update();
  window.addEventListener('scroll', onScroll, { passive: true });
  window.addEventListener('pageshow', update);
}());