https://trygrove.app/polish.js

1// Grove site polish: scroll-reveal engine (quiet fades, per Grove motion rules)
2(function(){
3  document.documentElement.classList.add('rv-enabled');
4  function init(){
5    if (!('IntersectionObserver' in window)) {
6      document.querySelectorAll('[data-reveal]').forEach(function(e){ e.classList.add('rv-in'); });
7      return;
8    }
9    var io = new IntersectionObserver(function(entries){
10      entries.forEach(function(en){
11        if (!en.isIntersecting) return;
12        var el = en.target;
13        var delay = el.getAttribute('data-reveal-delay');
14        if (delay == null && el.parentNode) {
15          var sibs = Array.prototype.filter.call(el.parentNode.children, function(c){ return c.hasAttribute && c.hasAttribute('data-reveal'); });
16          var idx = sibs.indexOf(el);
17          delay = idx > 0 ? Math.min(idx * 90, 450) + 'ms' : '0ms';
18        }
19        el.style.transitionDelay = delay || '0ms';
20        el.classList.add('rv-in');
21        io.unobserve(el);
22      });
23    }, { threshold: 0.1, rootMargin: '0px 0px -50px 0px' });
24    var seen = new WeakSet();
25    function scan(){
26      document.querySelectorAll('[data-reveal]').forEach(function(el){
27        if (seen.has(el)) return;
28        seen.add(el);
29        io.observe(el);
30      });
31    }
32    // An element the viewport has already passed will never intersect again, so the
33    // observer alone would leave it faded out for good. That happens on any load that
34    // jumps straight down the page — a #faq deep link, a restored scroll position —
35    // so sweep everything above the viewport in without animating it.
36    function sweepPassed(){
37      document.querySelectorAll('[data-reveal]:not(.rv-in)').forEach(function(el){
38        if (el.getBoundingClientRect().bottom <= 0) {
39          el.style.transitionDelay = '0ms';
40          el.classList.add('rv-in');
41          io.unobserve(el);
42        }
43      });
44    }
45    var queued = false;
46    function queueSweep(){
47      if (queued) return;
48      queued = true;
49      requestAnimationFrame(function(){ queued = false; sweepPassed(); });
50    }
51    scan();
52    queueSweep();
53    new MutationObserver(function(){ scan(); queueSweep(); }).observe(document.body, { childList: true, subtree: true });
54    addEventListener('scroll', queueSweep, { passive: true });
55    addEventListener('hashchange', queueSweep);
56    addEventListener('load', queueSweep);
57  }
58  if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', init); else init();
59})();