fix(medical-record): Remove z-index property (#15790)

diff --git a/erpnext/healthcare/page/medical_record/medical_record.css b/erpnext/healthcare/page/medical_record/medical_record.css
index 70014da..977625b 100644
--- a/erpnext/healthcare/page/medical_record/medical_record.css
+++ b/erpnext/healthcare/page/medical_record/medical_record.css
@@ -14,10 +14,6 @@
 	margin-bottom: -4px;
 }
 
-.medical_record-row > * {
-	z-index: -999;
-}
-
 .date-indicator {
     background:none;
     font-size:12px;