diff --git a/assets/css/jekyll-theme-chirpy.scss b/assets/css/jekyll-theme-chirpy.scss
index 442334d..b5ceb51 100644
--- a/assets/css/jekyll-theme-chirpy.scss
+++ b/assets/css/jekyll-theme-chirpy.scss
@@ -1,7 +1,14 @@
 ---
 ---
 
-@import 'main';
+@import 'main
+{%- if jekyll.environment == 'production' -%}
+  .bundle
+{%- endif -%}
+';
+
+/* append your custom style below */
+
 @import url("https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.8/dist/web/static/pretendard.css");
 
 /* append your custom style below */