diff --git a/map/michi/michi.html b/map/michi/michi.html
index a3a5305..b7dcfef 100644
--- a/map/michi/michi.html
+++ b/map/michi/michi.html
@@ -2,6 +2,9 @@
 <html lang="ja">
     <head>
         <title>道案内</title>
+        <style>
+        div#mymap {width: 90vw; height: 80vh; border: 1px navy solid;}
+        </style>
         <meta name="viewport" content="width=device-width, initial-scale=1" />
         <link rel="stylesheet" type="text/css" href="../src/leaflet.css" />
         <script type="text/javascript" src="../src/leaflet.js" charset="utf-8"></script>
