--- a/index.html
+++ b/index.html
@@ -20,7 +20,8 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <title>Space Invectors v2</title>
+    <title>Space Invectors</title>
+    <meta http-equiv="Content-Security-Policy" content="default-src 'none'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; connect-src 'none'; media-src 'none'">
     <link rel="stylesheet" href="./css/game.css" />
     <link rel="shortcut icon" href="./svg/icon.svg" />
     <script type="module">
@@ -45,6 +46,15 @@
   </head>
 
   <body>
+    <script>
+      // FredyGames: the arena has a fixed size (about 1300 x 850 px); shrink it to fit smaller windows.
+      function fitArena() {
+        var z = Math.min(1, window.innerWidth / 1300, window.innerHeight / 850);
+        document.getElementById("game-arena").style.zoom = z;
+      }
+      window.addEventListener("resize", fitArena);
+      document.addEventListener("DOMContentLoaded", fitArena);
+    </script>
     <main>
       <section id="start-lobby" class="active">
         <div class="box">
@@ -57,9 +67,6 @@
           </p>
           <div class="box--buttons">
             <button id="lobby--start-button">Play</button>
-            <a href="https://codeberg.org/camelia/space-invectors"
-               ><button>Source</button></a
-             >
           </div>
         </div>
         <noscript>