1 files changed, 48 insertions, 0 deletions
diff --git a/src/static/js/client.js b/src/static/js/client.js
index fe45ba16..49326663 100644
--- a/src/static/js/client.js
+++ b/src/static/js/client.js
@@ -1045,6 +1045,54 @@ if (
     });
 }
 
+// Links nested in summaries ------------------------------
+
+const summaryNestedLinksInfo = initInfo('summaryNestedLinksInfo', {
+  summaries: null,
+  links: null,
+});
+
+function getSummaryNestedLinksReferences() {
+  const info = summaryNestedLinksInfo;
+
+  info.summaries =
+    Array.from(document.getElementsByTagName('summary'));
+
+  info.links =
+    info.summaries
+      .map(summary =>
+        Array.from(summary.getElementsByTagName('a')));
+
+  filterMultipleArrays(
+    info.summaries,
+    info.links,
+    (_summary, links) => !empty(links));
+}
+
+function addSummaryNestedLinksPageListeners() {
+  const info = summaryNestedLinksInfo;
+
+  for (const {summary, links} of stitchArrays({
+    summary: info.summaries,
+    links: info.links,
+  })) {
+    for (const link of links) {
+      link.addEventListener('mouseover', () => {
+        link.classList.add('nested-hover');
+        summary.classList.add('has-nested-hover');
+      });
+
+      link.addEventListener('mouseout', () => {
+        link.classList.remove('nested-hover');
+        summary.classList.remove('has-nested-hover');
+      });
+    }
+  }
+}
+
+clientSteps.getPageReferences.push(getSummaryNestedLinksReferences);
+clientSteps.getPageReferences.push(addSummaryNestedLinksPageListeners);
+
 // Tooltip-style hover (infrastructure) -------------------
 
 const hoverableTooltipInfo = initInfo('hoverableTooltipInfo', {