chore: improve 404 page

apps/classroomio-com/src/routes/+layout.svelte

@@ -1,7 +1,9 @@
 <script>
+  import { page } from '$app/stores';
   import Navigation from '$lib/Navigation/Navigation.svelte';
   import Footer from '$lib/Footer/Footer.svelte';
   import PageTransition from './transition.svelte';
+  import NotFound from '$lib/NotFound/NotFound.svelte';
 
   import '../app.css';
 
@@ -12,7 +14,11 @@
   <Navigation />
 
   <PageTransition url={data.url}>
-    <slot />
+    {#if $page.status === 404}
+      <NotFound className="mt-5" />
+    {:else}
+      <slot />
+    {/if}
   </PageTransition>
 
   <Footer />