diff --git a/intoro/websocket/websocket.html b/intoro/websocket/websocket.html
index 1e24465..948d704 100644
--- a/intoro/websocket/websocket.html
+++ b/intoro/websocket/websocket.html
@@ -2,6 +2,7 @@
 <html lang="ja">
   <head>
     <meta http-equiv="content-type" charset="utf-8">
+    <link rel="stylesheet" href="websocket.css">
     <script type="text/javascript" src="websocket.js" charset="utf-8"></script>
     <title>イントロクイズ</title>
 
