diff --git a/404.html b/404.html
index 22bb61085..10c9655ee 100644
--- a/404.html
+++ b/404.html
@@ -4,10 +4,58 @@
 layout: default
 id: not-found
 ---
-<script async src="https://cse.google.com/cse.js?cx=000547254117280036387:qwl-zdl2sn0">
-</script>
-<div class="gcse-search">
-</div>
-<div style="position: relative; padding-bottom: 100%; height: 0; overflow: hidden;">
-  <iframe name="embed_readwrite" src="https://pad.riseup.net/p/short-ref-keep?showControls=false&showChat=false&showLineNumbers=true&useMonospaceFont=true&noColors=true&alwaysShowChat=false&chatAndUsers=false" width="100%" height="600" frameborder="0"></iframe>
+
+<style>
+    body {
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        height: 100vh;
+        margin: 0;
+        background-color: #f8f9fa;
+        color: #343a40;
+    }
+    .container {
+        text-align: center;
+        padding: 20px;
+        max-width: 800px;
+        margin: auto;
+    }
+    h1 {
+        font-size: 2em;
+        margin-bottom: 0.5em;
+    }
+    p {
+        margin-bottom: 1em;
+    }
+    .gcse-search {
+        margin-bottom: 1em;
+    }
+    .iframe-container {
+        position: relative;
+        padding-bottom: 56.25%; /* 16:9 aspect ratio */
+        height: 0;
+        overflow: hidden;
+        width: 100%;
+        max-width: 100%;
+        background-color: #ffffff;
+        border: 1px solid #ced4da;
+        border-radius: 0.25rem;
+    }
+    .iframe-container iframe {
+        position: absolute;
+        top: 0;
+        left: 0;
+        width: 100%;
+        height: 100%;
+        border: 0;
+    }
+</style>
+<script async src="https://cse.google.com/cse.js?cx=000547254117280036387:qwl-zdl2sn0"></script>
+
+<div class="container">
+    <div class="gcse-search"></div>
+    <div class="iframe-container">
+        <iframe name="embed_readwrite" src="https://pad.riseup.net/p/short-ref-keep?showControls=false&showChat=false&showLineNumbers=true&useMonospaceFont=true&noColors=true&alwaysShowChat=false&chatAndUsers=false" frameborder="0"></iframe>
+    </div>
 </div>