diff --git a/test/demo/collections/index.html b/test/demo/collections/index.html
index e434574d..46b4e7f2 100644
--- a/test/demo/collections/index.html
+++ b/test/demo/collections/index.html
@@ -5,6 +5,25 @@
         <script type="text/javascript" src='../../../build/openseadragon/openseadragon.js'></script>
         <script type="text/javascript" src='../../lib/jquery-1.9.1.min.js'></script>
         <script type="text/javascript" src='main.js'></script>
+        <style type="text/css">
+
+            html,
+            body,
+            .openseadragon1 {
+                width: 100%;
+                height: 100%;
+                margin: 0;
+            }
+
+            .openseadragon1.small {
+                width: 50%;
+            }
+
+            .openseadragon-overlay {
+                background-color: rgba(255, 0, 0, 0.3);
+            }
+
+        </style>
     </head>
     <body>
         <div id="contentDiv" class="openseadragon1"></div>
