(function () {
  'use strict';

  // --- Nav scroll state ---
  var nav = document.getElementById('nav');
  if (nav) {
    window.addEventListener('scroll', function () {
      if (window.scrollY > 40) {
        nav.classList.add('nav--scrolled');
      } else {
        nav.classList.remove('nav--scrolled');
      }
    }, { passive: true });
  }

  // --- Terminal animations via IntersectionObserver ---
  var animatedEls = document.querySelectorAll('[data-animate]');
  if (animatedEls.length) {
    var animObserver = new IntersectionObserver(function (entries) {
      entries.forEach(function (entry) {
        if (entry.isIntersecting) {
          entry.target.classList.add('play');
          animObserver.unobserve(entry.target);
        }
      });
    }, { threshold: 0.3 });

    animatedEls.forEach(function (el) {
      animObserver.observe(el);
    });
  }

  // --- Fade-in elements via IntersectionObserver ---
  var fadeEls = document.querySelectorAll('.fade-in');
  if (fadeEls.length) {
    var fadeObserver = new IntersectionObserver(function (entries) {
      entries.forEach(function (entry) {
        if (entry.isIntersecting) {
          entry.target.classList.add('visible');
          fadeObserver.unobserve(entry.target);
        }
      });
    }, { threshold: 0.1 });

    fadeEls.forEach(function (el) {
      fadeObserver.observe(el);
    });
  }

  // --- Clipboard copy ---
  document.addEventListener('click', function (e) {
    var btn = e.target.closest('[data-copy], .copy-btn');
    if (!btn) return;

    var text = btn.getAttribute('data-copy');
    if (!text) {
      var block = btn.closest('.code-block');
      if (block) text = block.getAttribute('data-copy');
    }
    if (!text) return;

    var original = btn.textContent;
    navigator.clipboard.writeText(text).then(function () {
      btn.textContent = 'Copied!';
      btn.classList.add('copied');
      setTimeout(function () {
        btn.textContent = original;
        btn.classList.remove('copied');
      }, 1500);
    });
  });

  // --- Sidebar filter (features page) ---
  var filterInput = document.getElementById('sidebar-filter');
  if (filterInput) {
    filterInput.addEventListener('input', function () {
      var query = filterInput.value.toLowerCase();
      var links = document.querySelectorAll('.sidebar__link');
      links.forEach(function (link) {
        link.style.display = link.textContent.toLowerCase().includes(query)
          ? 'block'
          : 'none';
      });
    });
  }
})();