diff --git a/index.html b/index.html
index d3bbc51..f8bc2e7 100644
--- a/index.html
+++ b/index.html
@@ -266,8 +266,16 @@
     var nr = nav.getBoundingClientRect();
     nav.classList.toggle('on-dark', darkBehind((nr.top + nr.bottom) / 2));
     if (menu && menu.classList.contains('open')) {
-      var mr = menu.getBoundingClientRect();
-      menu.classList.toggle('on-dark', darkBehind((mr.top + mr.bottom) / 2));
+      // Flip the menu when the dark boundary reaches its TEXT — the lowest link's
+      // leading edge — not the panel's midpoint. The links are top-anchored, so the
+      // midpoint sits well below them: by the time dark reached it, the text had
+      // already been over dark. Probing the lowest link makes the switch land as the
+      // boundary enters the text, just like the (thin) nav bar flips at its content.
+      var links = menu.querySelectorAll('a');
+      var probe = links.length
+        ? links[links.length - 1].getBoundingClientRect().bottom
+        : (function () { var mr = menu.getBoundingClientRect(); return (mr.top + mr.bottom) / 2; })();
+      menu.classList.toggle('on-dark', darkBehind(probe));
     }
   }
   updateNavTheme();