diff --git a/wwwroot/css/calendar-layout-css.css b/wwwroot/css/calendar-layout-css.css
index 4618c4c..088febb 100644
--- a/wwwroot/css/calendar-layout-css.css
+++ b/wwwroot/css/calendar-layout-css.css
@@ -212,7 +212,7 @@ swp-week-header {
   border-bottom: 1px solid var(--color-border);
   position: sticky;
   top: 0;
-  z-index: 5; /* Higher than time-axis to cover it when scrolling */
+  z-index: 3; /* Lower than header-spacer so it slides under during horizontal scroll */
   height: 80px; /* Fixed height */
 }