diff --git a/demo/index.html b/demo/index.html
index 3d10c88..1e9b66a 100644
--- a/demo/index.html
+++ b/demo/index.html
@@ -7,6 +7,17 @@
     padding: 0.2em;
     margin-bottom: 1em;
   }
+
+  body {
+    font-family: sans-serif;
+    max-width: 45rem;
+    margin: 0 auto;
+    padding: 1rem;
+  }
+
+  pre {
+    overflow-x: auto;
+  }
 </style>
 
 <label for="token-input">Access token: </label>