diff --git a/nextjs-app/components/school/SchoolDetailShell.module.css b/nextjs-app/components/school/SchoolDetailShell.module.css
index dcc4f9c..c519195 100644
--- a/nextjs-app/components/school/SchoolDetailShell.module.css
+++ b/nextjs-app/components/school/SchoolDetailShell.module.css
@@ -270,23 +270,11 @@
     position: sticky;
     top: 64px; /* global header height on desktop */
     z-index: 10;
-    /* `position: sticky` with a z-index makes this a stacking context, so the
-       jump sheet's own z-index only orders it INSIDE here. Against the fixed
-       bottom tab bar (Navigation.module.css, z-index 1000) what counts is this
-       value — which is why the sheet's last item was painted over, and
-       untappable, once the list grew long enough to reach the bar. Lifted only
-       while the sheet is open, and only to 1100: below the comparison toast
-       (2000), the fullscreen map (5000) and the info popover (9999). */
     background: var(--bg-card);
     border: 1px solid var(--border);
     border-top: none;
     border-radius: 0 0 10px 10px;
     padding: 0.5rem 0.75rem;
-}
-
-
-.sectionNavSheetOpen {
-    z-index: 1100;
     margin-bottom: 1rem;
     box-shadow: 0 2px 4px rgba(var(--shadow-rgb), 0.04);
     display: flex;
@@ -295,6 +283,21 @@
 }
 
 
+/* `position: sticky` with a z-index makes .sectionNav a stacking context, so
+   the jump sheet's own z-index only orders it INSIDE that context. Against the
+   fixed bottom tab bar (Navigation.module.css, z-index 1000) what counts is
+   .sectionNav's 10 — which is why the sheet's last item was painted over, and
+   untappable, once the list grew long enough to reach the bar.
+
+   Lifted only while the sheet is open, and only to 1100: above the bar, below
+   the comparison toast (2000), the fullscreen map (5000) and the info popover
+   (9999). This rule carries the z-index and nothing else; every other
+   declaration belongs to .sectionNav in both states. */
+.sectionNavSheetOpen {
+    z-index: 1100;
+}
+
+
 .sectionNavBack {
     flex: none;
     display: inline-flex;