feat: add stagger entry animation to showcase on load and shuffle

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/static/js/showcase.js

@@ -4,8 +4,6 @@
 (function() {
   'use strict';
 
-  // Use shared TagUtils module
-  const { formatTagHtml, createTagChipHtml } = window.TagUtils || {};
 
   const container = document.getElementById('showcaseGrid');
   if (!container) return;
@@ -59,7 +57,7 @@
 
     try {
       const images = JSON.parse(dataScript.textContent);
-      distributeImages(images, true); // Use lazy loading for initial images (some may be below fold)
+      distributeImages(images, true, true); // animate on initial load
     } catch (e) {
       console.error('Failed to parse initial images:', e);
     }
@@ -174,20 +172,23 @@
     return item;
   }
 
-  function distributeImages(images, useLazyLoading = false) {
-    images.forEach(img => {
+  function distributeImages(images, useLazyLoading = false, animate = false) {
+    images.forEach((img, i) => {
       const colIndex = getShortestColumnIndex();
       const item = createImageElement(img, useLazyLoading);
+
+      if (animate) {
+        item.style.setProperty('--stagger-index', i);
+        item.classList.add('animating-in');
+        // Remove class after animation completes so it doesn't block interactions
+        const delay = i * 60;
+        setTimeout(() => item.classList.remove('animating-in'), delay + 300);
+      }
+
       columns[colIndex].appendChild(item);
-
-      // Update height estimate (will be corrected after image loads)
       columnHeights[colIndex] += 300;
-
-      // Correct height after image loads
       const imgEl = item.querySelector('img');
-      imgEl.onload = () => {
-        updateColumnHeights();
-      };
+      imgEl.onload = () => { updateColumnHeights(); };
     });
 
     document.dispatchEvent(new CustomEvent('showcaseUpdated'));
@@ -236,7 +237,7 @@
       columns.forEach(col => col.innerHTML = '');
       columnHeights = columnHeights.map(() => 0);
 
-      distributeImages(data.images);
+      distributeImages(data.images, false, true); // animate on shuffle
 
       // Scroll to top
       window.scrollTo({ top: 0, behavior: 'smooth' });

app/static/style.css

@@ -1394,6 +1394,24 @@ header {
   transition: opacity 0.3s ease;
 }
 
+/* Stagger entry animation for showcase items */
+@keyframes itemFadeIn {
+  from {
+    opacity: 0;
+    transform: translateY(12px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.masonry-item.animating-in {
+  animation: itemFadeIn 0.25s ease forwards;
+  animation-delay: calc(var(--stagger-index, 0) * 60ms);
+  opacity: 0; /* Start hidden until animation fires */
+}
+
 /*------------------------------------------------------------------------------
   Forms
 ------------------------------------------------------------------------------*/