1 files changed, 34 insertions, 0 deletions
diff --git a/src/static/client.js b/src/static/client.js
index 87b7400..4eb1d2b 100644
--- a/src/static/client.js
+++ b/src/static/client.js
@@ -452,6 +452,8 @@ function addHashLinkHandlers() {
   // This lets the scroll offset be consolidated where it makes sense, and
   // sets an appropriate offset when (re)loading a page with hash for free!
 
+  let wasHighlighted;
+
   for (const a of document.links) {
     const href = a.getAttribute('href');
     if (!href || !href.startsWith('#')) {
@@ -469,6 +471,17 @@ function addHashLinkHandlers() {
     const href = evt.target.getAttribute('href');
     const id = href.slice(1);
     const linked = document.getElementById(id);
+
+    if (!linked) {
+      return;
+    }
+
+    // Hide skipper box right away, so the layout is updated on time for the
+    // math operations coming up next.
+    const skipper = document.getElementById('skippers');
+    skipper.style.display = 'none';
+    setTimeout(() => skipper.style.display = '');
+
     const box = linked.getBoundingClientRect();
     const style = window.getComputedStyle(linked);
 
@@ -480,6 +493,27 @@ function addHashLinkHandlers() {
     evt.preventDefault();
     history.pushState({}, '', href);
     window.scrollTo({top: scrollY, behavior: 'smooth'});
+    linked.focus({preventScroll: true});
+
+    const maxScroll =
+        document.body.scrollHeight
+      - window.innerHeight;
+
+    if (scrollY > maxScroll && linked.classList.contains('content-heading')) {
+      if (wasHighlighted) {
+        wasHighlighted.classList.remove('highlight-hash-link');
+      }
+
+      wasHighlighted = linked;
+      linked.classList.add('highlight-hash-link');
+      linked.addEventListener('animationend', function handle(evt) {
+        if (evt.animationName === 'highlight-hash-link') {
+          linked.removeEventListener('animationend', handle);
+          linked.classList.remove('highlight-hash-link');
+          wasHighlighted = null;
+        }
+      });
+    }
   }
 }