diff --git a/userscripts/style-webtoons.js b/userscripts/style-webtoons.js
index 85dac6d..0bd15c3 100644
--- a/userscripts/style-webtoons.js
+++ b/userscripts/style-webtoons.js
@@ -26,5 +26,6 @@ function injectStyle(css) {
   max-width: 300px;
   min-width: 300px;
   height: auto;
+  border: 1px solid #ccc;
 }`);
 })();