diff --git a/themes/leilukin/stylesheets/all.css b/themes/leilukin/stylesheets/all.css
index a31123c..aa77533 100644
--- a/themes/leilukin/stylesheets/all.css
+++ b/themes/leilukin/stylesheets/all.css
@@ -371,7 +371,7 @@ form, fieldset {
 form.search_box {
     display: block;
     position: relative;
-    width: 12em;
+    max-width: 12em;
     margin-bottom: 2rem;
 }
 form.comment_edit {