diff --git a/_layouts/default.html b/_layouts/default.html
new file mode 100644
index 0000000..2cbc6d9
--- /dev/null
+++ b/_layouts/default.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<html lang="{{ site.lang | default: "en-US" }}">
+  <head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+
+{% seo %}
+    <link rel="stylesheet" href="{{ "/assets/css/style.css?v=" | append: site.github.build_revision | relative_url }}">
+    <style>
+      .rfc {
+          color: #d55;
+          font-variant: small-caps;
+          font-style: normal;
+          font-weight: normal;
+      }
+    </style>
+  </head>
+  <body>
+    <div class="container-lg px-3 my-5 markdown-body">
+
+      {% if page.url == "/" %}
+      <a href="/" title="Back to the Readium project site.">
+        <img src="https://readium.org/assets/logos/readium-logo.png" alt="Readium Logo" width="250">
+      </a>
+      {% else %}
+      <a href="/architecture/" title="Back to the index page.">
+        <img src="https://readium.org/assets/logos/readium-logo.png" alt="Readium Logo" width="250">
+      </a>
+      {% endif %}
+
+      {{ content }}
+
+      {% if site.github.private != true and site.github.license %}
+      <div class="footer border-top border-gray-light mt-5 pt-3 text-right text-gray">
+        This site is open source. {% github_edit_link "Improve this page" %}.
+      </div>
+      {% endif %}
+    </div>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/anchor-js/4.1.0/anchor.min.js" integrity="sha256-lZaRhKri35AyJSypXXs4o6OPFTbTmUoltBbDCbdzegg=" crossorigin="anonymous"></script>
+    <script>anchors.add();</script>
+  </body>
+</html>
