diff --git a/index.html b/index.html
index db5f7f8..f6f8ba0 100644
--- a/index.html
+++ b/index.html
@@ -12,7 +12,7 @@
     <style>
         .CodeMirror {
           border: 1px solid #eee;
-          height: auto;
+          height: 70%;
         }
     </style>
   </head>