diff --git a/security/manager/pki/resources/content/deletecert.css b/security/manager/pki/resources/content/deletecert.css
index 4607f0a44af8..b959b9c49243 100644
--- a/security/manager/pki/resources/content/deletecert.css
+++ b/security/manager/pki/resources/content/deletecert.css
@@ -12,8 +12,13 @@ dialog::part(content-box) {
   contain: inline-size;
 }
 
+#impact {
+  margin-block-start: 12px;
+}
+
 #certlist {
   flex: 1;
   min-height: 8em;
+  contain: size;
   min-width: 35em;
 }