feat(navigate) navigation available and most usefull features)

structure/main.php

@@ -1,6 +1,8 @@
 <?php 
 session_start();
 
+include 'config.php';
+
 $page = basename($_SERVER['PHP_SELF']);
 if (!isset($_SESSION['user_id']) && $page !== 'login.php' && $page !== 'register.php') {
     header("Location: login.php");
@@ -16,10 +18,17 @@ include 'services/db.php';
     
 ?>
 
-<main class="container mt-5">
+<main class="container mt-4">
     <?php include $content; ?>
 </main>
 
 <?php include 'structure/footer.php'; ?>
+
+<script>
+    window.addEventListener('load', function() {
+        document.body.style.display = 'block';
+    });
+</script>
+
 </body>
 </html>