diff --git a/404.html b/404.html
new file mode 100644
index 0000000..550e35c
--- /dev/null
+++ b/404.html
@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8" />
+    <title>Single Page Apps for GitHub Pages</title>
+    <script type="text/javascript">
+      // Single Page Apps for GitHub Pages
+      // MIT License
+      // https://github.com/rafgraph/spa-github-pages
+      // This script takes the current url and converts the path and query
+      // string into just a query string, and then redirects the browser
+      // to the new url with only a query string and hash fragment,
+      // e.g. https://www.foo.tld/one/two?a=b&c=d#qwe, becomes
+      // https://www.foo.tld/?/one/two&a=b~and~c=d#qwe
+      // Note: this 404.html file must be at least 512 bytes for it to work
+      // with Internet Explorer (it is currently > 512 bytes)
+
+      // If you're creating a Project Pages site and NOT using a custom domain,
+      // then set pathSegmentsToKeep to 1 (enterprise users may need to set it to > 1).
+      // This way the code will only replace the route part of the path, and not
+      // the real directory in which the app resides, for example:
+      // https://username.github.io/repo-name/one/two?a=b&c=d#qwe becomes
+      // https://username.github.io/repo-name/?/one/two&a=b~and~c=d#qwe
+      // Otherwise, leave pathSegmentsToKeep as 0.
+      var pathSegmentsToKeep = 1;
+
+      var l = window.location;
+      l.replace(
+        l.protocol +
+          '//' +
+          l.hostname +
+          (l.port ? ':' + l.port : '') +
+          l.pathname
+            .split('/')
+            .slice(0, 1 + pathSegmentsToKeep)
+            .join('/') +
+          '/?/' +
+          l.pathname.slice(1).split('/').slice(pathSegmentsToKeep).join('/').replace(/&/g, '~and~') +
+          (l.search ? '&' + l.search.slice(1).replace(/&/g, '~and~') : '') +
+          l.hash
+      );
+    </script>
+  </head>
+  <body></body>
+</html>
diff --git a/index.html b/index.html
index a9f8ddc..86f786c 100644
--- a/index.html
+++ b/index.html
@@ -11,6 +11,33 @@
       href="https://fonts.googleapis.com/css2?family=Open+Sans:wght@300;400;600&family=Source+Sans+3:wght@300;400;600&display=swap"
       rel="stylesheet"
     />
+
+    <!-- Start Single Page Apps for GitHub Pages -->
+    <script type="text/javascript">
+      // Single Page Apps for GitHub Pages
+      // MIT License
+      // https://github.com/rafgraph/spa-github-pages
+      // This script checks to see if a redirect is present in the query string,
+      // converts it back into the correct url and adds it to the
+      // browser's history using window.history.replaceState(...),
+      // which won't cause the browser to attempt to load the new url.
+      // When the single page app is loaded further down in this file,
+      // the correct url will be waiting in the browser's history for
+      // the single page app to route accordingly.
+      (function (l) {
+        if (l.search[1] === '/') {
+          var decoded = l.search
+            .slice(1)
+            .split('&')
+            .map(function (s) {
+              return s.replace(/~and~/g, '&');
+            })
+            .join('?');
+          window.history.replaceState(null, null, l.pathname.slice(0, -1) + decoded + l.hash);
+        }
+      })(window.location);
+    </script>
+    <!-- End Single Page Apps for GitHub Pages -->
     <script type="module" crossorigin src="/pizza-app/assets/index-CAqOY3Qd.js"></script>
     <link rel="stylesheet" crossorigin href="/pizza-app/assets/index-DxRjbygg.css">
   </head>
