diff --git a/docs/www/.htaccess b/docs/www/.htaccess
index c78f08e..2ded313 100644
--- a/docs/www/.htaccess
+++ b/docs/www/.htaccess
@@ -11,3 +11,9 @@ RewriteRule ^(.*)$ $1/ [R=301,L]
 RewriteCond %{REQUEST_FILENAME} !-d
 RewriteCond %{REQUEST_FILENAME}\.php -f
 RewriteRule ^([^\.]+)/$ $1.php
+
+# Custom error pages
+ErrorDocument 403 /errors/403.php
+ErrorDocument 404 /errors/404.php
+ErrorDocument 500 /errors/500.php
+ErrorDocument 503 /errors/503.php
diff --git a/docs/www/errors/403.php b/docs/www/errors/403.php
new file mode 100644
index 0000000..545800e
--- /dev/null
+++ b/docs/www/errors/403.php
@@ -0,0 +1,17 @@
+<?php
+$COMMONS = $_SERVER['DOCUMENT_ROOT'] . "/../common";
+
+include_once($COMMONS."/header.php");
+display_header("403: Forbidden");
+?>
+
+<article>
+<h2>403: Forbidden</h2>
+<div class="centered-container">
+<img src="https://assets.zdenekborovec.cz/upload/3e0cef92-8dad-4085-9db4-e9c8e1437e0a/c7ec620b-1666-4ab9-ad35-ad3daf1b53b2.png" alt="Internet meme image of a confused-looking cat with a text reading &quot;Hey you... What are you doing here??&quot;">
+</div>
+</article>
+
+<?php
+include_once($COMMONS."/footer.php");
+?>
diff --git a/docs/www/errors/404.php b/docs/www/errors/404.php
new file mode 100644
index 0000000..9a52f06
--- /dev/null
+++ b/docs/www/errors/404.php
@@ -0,0 +1,17 @@
+<?php
+$COMMONS = $_SERVER['DOCUMENT_ROOT'] . "/../common";
+
+include_once($COMMONS."/header.php");
+display_header("404: Not Found");
+?>
+
+<article>
+<h2>404: Not Found</h2>
+<div class="centered-container">
+<img src="https://assets.zdenekborovec.cz/upload/7316caee796b4cb280cc769ea5f852fa/32a6269147ce4c6c813d4f0449ae1da9/9f532c593d134c6dad5bc63684fe22c2" alt="GIF of a cat hiding in a cupboard">
+</div>
+</article>
+
+<?php
+include_once($COMMONS."/footer.php");
+?>
diff --git a/docs/www/errors/500.php b/docs/www/errors/500.php
new file mode 100644
index 0000000..df811b6
--- /dev/null
+++ b/docs/www/errors/500.php
@@ -0,0 +1,17 @@
+<?php
+$COMMONS = $_SERVER['DOCUMENT_ROOT'] . "/../common";
+
+include_once($COMMONS."/header.php");
+display_header("500: Internal Server Error");
+?>
+
+<article>
+<h2>500: Internal Server Error</h2>
+<div class="centered-container">
+<img src="https://assets.zdenekborovec.cz/upload/bddac3669dd44acc8a41e2f935c94a3a/0c5f9e325ba34c02a24f53e50a1cc68d/62aa400be23d4c5ab3f6e2abe666d070" alt="GIF of a very confused cat.">
+</div>
+</article>
+
+<?php
+include_once($COMMONS."/footer.php");
+?>
diff --git a/docs/www/errors/503.php b/docs/www/errors/503.php
new file mode 100644
index 0000000..7d102de
--- /dev/null
+++ b/docs/www/errors/503.php
@@ -0,0 +1,17 @@
+<?php
+$COMMONS = $_SERVER['DOCUMENT_ROOT'] . "/../common";
+
+include_once($COMMONS."/header.php");
+display_header("503: Service Unavailable");
+?>
+
+<article>
+<h2>503: Service Unavailable</h2>
+<div class="centered-container">
+<img src="https://assets.zdenekborovec.cz/upload/db3181344f0249a09fbc2ba1096b35c4/4b974e9c1e214ea4ad57174a33aa1c4f/bb9d675f430f4fd8990fd3a993a7ee96" alt="GIF of a cat going to work in a cardboard box.">
+</div>
+</article>
+
+<?php
+include_once($COMMONS."/footer.php");
+?>