diff --git a/pkg/web_css/lib/src/_list.scss b/pkg/web_css/lib/src/_list.scss
index 2d15aee28f..816e36c23e 100644
--- a/pkg/web_css/lib/src/_list.scss
+++ b/pkg/web_css/lib/src/_list.scss
@@ -47,7 +47,9 @@
 }
 
 .listing-highlight-block {
-  margin: 8px 0px;
+  border-left: 0.25em solid var(--pub-markdown-alert-note);
+  padding: .5rem 1rem;
+  margin: 4px 0px;
 }
 
 .sort-control {