diff --git a/kadai10.html b/kadai10.html
index 0a9e2f1..ce8d007 100644
--- a/kadai10.html
+++ b/kadai10.html
@@ -2,7 +2,11 @@
 <html>
 <head>
 <title>たいとる</title>
-<link rel="stylesheet" type="text/css" href="main.css">
+<style type="text/css">
+<!--
+span.check {color: red; background: red;}
+-->
+</style>
 <script type="text/javascript" src="kadai10.js"></script>
 </head>
 
