Hide shared-page update-time row in read-only mode

Author: alvin000009238

grades_dashboard.css

@@ -1662,6 +1662,10 @@ body.read-only-mode #logoutBtn {
     display: none !important;
 }
 
+body.read-only-mode .data-time-box .time-info {
+    display: none;
+}
+
 body.read-only-mode .header {
     border-bottom: 1px solid var(--color-warning-muted);
-}
+}