progressive enhancement for collection filter pills

Flex-wrap base (no JS needed, active pill always visible). JS hook
switches to horizontal scroll with scroll-into-view when pills exceed
2.5 rows on mobile. Desktop always wraps.

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

assets/css/theme-semantic.css

@@ -206,19 +206,66 @@
   }
 }
 
-/* Horizontal scroll fade hint for collection category pills (mobile only) */
-.collection-filter-scroll {
+/* Collection filter pills — flex-wrap base, JS-enhanced scroll on mobile */
+.collection-filter-pills {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.375rem;
+}
+
+.collection-filter-pill {
+  display: inline-block;
+  padding: 0.375rem 0.75rem;
+  border-radius: 9999px;
+  font-size: 0.75rem;
+  white-space: nowrap;
+  transition: opacity 0.15s;
+  background-color: var(--t-surface-raised);
+  color: var(--t-text-primary);
+
+  &.active {
+    background-color: var(--t-accent);
+    color: var(--t-text-on-accent);
+    font-weight: 500;
+  }
+}
+
+/* When JS detects overflow, it adds this class to switch to horizontal scroll */
+.collection-filters.is-scrollable {
+  overflow-x: auto;
+  scrollbar-width: none;
+  -webkit-overflow-scrolling: touch;
   mask-image: linear-gradient(to right, black calc(100% - 2rem), transparent);
   -webkit-mask-image: linear-gradient(to right, black calc(100% - 2rem), transparent);
-  scrollbar-width: none;
 
   &::-webkit-scrollbar {
     display: none;
   }
 
-  @media (min-width: 640px) {
+  & .collection-filter-pills {
+    flex-wrap: nowrap;
+  }
+}
+
+@media (min-width: 640px) {
+  .collection-filter-pills {
+    gap: 0.5rem;
+  }
+
+  .collection-filter-pill {
+    padding: 0.5rem 1rem;
+    font-size: 0.875rem;
+  }
+
+  /* Desktop always wraps — no scroll needed */
+  .collection-filters.is-scrollable {
+    overflow-x: visible;
     mask-image: none;
     -webkit-mask-image: none;
+
+    & .collection-filter-pills {
+      flex-wrap: wrap;
+    }
   }
 }