diff --git a/404.php  b/404.php 
new file mode 100644
index 0000000..3e4762c
--- /dev/null
+++ b/404.php 	
@@ -0,0 +1,15 @@
+<?php
+session_start();
+include 'include/header.php';
+?>
+
+<main>
+    <div style="text-align: center; padding: 80px 20px;">
+        <h1 style="font-size: 5em; color: #3bc4e8; margin-bottom: 10px;">404</h1>
+        <h2 style="font-size: 1.5em; margin-bottom: 15px;">Page introuvable</h2>
+        <p style="color: #aaa; margin-bottom: 30px;">La page que vous cherchez n'existe pas ou a été déplacée.</p>
+        <a href="dashboard.php" class="btn-primary">🏠 Retour au dashboard</a>
+    </div>
+</main>
+
+<?php include 'include/footer.php'; ?>
\ No newline at end of file