feat(pages): add page opening, page deletion API, edit mode toggle and custom 404 page

src/pages/404.astro

@@ -0,0 +1,25 @@
+---
+// src/pages/404.astro
+import Layout from '../layouts/Layout.astro';
+---
+
+<Layout title="404 - Seite nicht gefunden | N&D IT Solutions">
+  <main class="min-h-screen bg-[#0B0F19] text-white flex items-center justify-center p-4">
+    <div class="preset-card p-10 bg-slate-900/80 border border-white/10 rounded-2xl max-w-lg w-full text-center space-y-6 shadow-2xl backdrop-blur-md">
+      <span class="text-6xl font-extrabold text-sky-400 font-mono tracking-widest block">404</span>
+      <h1 class="text-2xl font-bold text-white">Seite nicht gefunden</h1>
+      <p class="text-slate-400 text-sm leading-relaxed">
+        Die von Ihnen angeforderte Seite existiert nicht oder wurde verschoben.
+      </p>
+
+      <div class="pt-4">
+        <a 
+          href="/" 
+          class="inline-block bg-sky-500 hover:bg-sky-400 text-slate-950 font-bold px-6 py-3 rounded-xl text-sm transition-all shadow-lg shadow-sky-500/20 active:scale-95"
+        >
+          ← Zurück zur Startseite
+        </a>
+      </div>
+    </div>
+  </main>
+</Layout>

src/pages/admin/index.astro

@@ -19,13 +19,17 @@ const presets = Object.values(THEME_PRESETS);
             <h1 class="text-3xl font-extrabold tracking-tight mt-1">System & Admin Dashboard</h1>
           </div>
           <div class="flex items-center gap-3">
+            <a id="toggle-preview-mode" href="/?preview=draft" target="_blank" class="px-4 py-2 rounded-xl bg-amber-500/10 text-amber-400 border border-amber-500/20 text-xs font-semibold hover:bg-amber-500 hover:text-slate-950 transition-all flex items-center gap-2">
+              🛠️ Bearbeitungsmodus (Entwurf-Vorschau)
+            </a>
             <a href="/" target="_blank" class="px-4 py-2 rounded-xl glass-panel text-xs font-semibold hover:border-sky-400 transition-all flex items-center gap-2">
-              🌐 Live Seite Ansehen
+              🌐 Live-Seite Ansehen
             </a>
             <button id="save-all-btn" class="px-6 py-2.5 rounded-xl bg-sky-400 text-slate-950 font-bold text-xs uppercase tracking-wider hover:bg-white transition-all shadow-lg shadow-sky-400/20 active:scale-95">
               Einstellungen Speichern
             </button>
           </div>
+
         </div>
 
         <!-- Quick Admin Nav Cards / Links -->

src/pages/admin/pages.astro

@@ -66,15 +66,35 @@ const currentHomepageId = (siteConfig as any).site_info?.homepage_id;
                 </td>
                 <td class="p-4 text-right space-x-2">
                   <a
-                    href={`/admin/editor/?page_id=${page.id}`}
-                    class="bg-slate-800 hover:bg-slate-700 text-white px-3 py-1.5 rounded text-xs font-medium inline-block transition-colors"
+                    href={page.slug}
+                    target="_blank"
+                    class="bg-slate-800 hover:bg-slate-700 text-sky-400 px-2.5 py-1.5 rounded text-xs font-medium inline-block transition-colors"
+                    title="Seite im Browser öffnen"
                   >
-                    ✏️ Im Editor öffnen
+                    🔗 Öffnen
                   </a>
+                  <a
+                    href={`/admin/editor/?page_id=${page.id}`}
+                    class="bg-sky-500/20 hover:bg-sky-500 text-sky-300 hover:text-slate-950 px-2.5 py-1.5 rounded text-xs font-medium inline-block transition-colors border border-sky-500/30"
+                  >
+                    ✏️ Editor
+                  </a>
+                  {!isHomepage && (
+                    <button
+                      type="button"
+                      data-page-id={page.id}
+                      data-page-title={page.title}
+                      class="btn-delete-page bg-red-500/10 hover:bg-red-500 text-red-400 hover:text-white px-2.5 py-1.5 rounded text-xs font-medium inline-block transition-colors border border-red-500/20"
+                      title="Seite löschen"
+                    >
+                      🗑️ Löschen
+                    </button>
+                  )}
                 </td>
               </tr>
             );
           })}
+
         </tbody>
       </table>
     </div>
@@ -138,4 +158,28 @@ const currentHomepageId = (siteConfig as any).site_info?.homepage_id;
       window.location.reload();
     }
   });
+
+  // Event: Seite löschen
+  document.querySelectorAll('.btn-delete-page').forEach(btn => {
+    btn.addEventListener('click', async (e: any) => {
+      const pageId = e.target.getAttribute('data-page-id');
+      const pageTitle = e.target.getAttribute('data-page-title');
+
+      if (!confirm(`Möchten Sie die Seite "${pageTitle}" wirklich unwiderruflich löschen?`)) return;
+
+      const res = await fetch('/api/admin/pages/delete', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ page_id: pageId })
+      });
+
+      if (res.ok) {
+        window.location.reload();
+      } else {
+        const data = await res.json();
+        alert(data.error || 'Fehler beim Löschen der Seite.');
+      }
+    });
+  });
 </script>
+

src/pages/api/admin/pages/delete.ts

@@ -0,0 +1,40 @@
+import type { APIRoute } from 'astro';
+import fs from 'node:fs/promises';
+import path from 'node:path';
+
+export const prerender = false;
+
+const DATA_DIR = process.env.DATA_DIR || path.join(process.cwd(), 'app', 'data');
+
+export const POST: APIRoute = async ({ request }) => {
+  try {
+    const { page_id } = await request.json();
+    if (!page_id) {
+      return new Response(JSON.stringify({ error: 'page_id erforderlich' }), { status: 400 });
+    }
+
+    const configPath = path.join(DATA_DIR, 'site.config.json');
+    let config: any = {};
+
+    try {
+      const rawData = await fs.readFile(configPath, 'utf-8');
+      config = JSON.parse(rawData);
+    } catch {
+      return new Response(JSON.stringify({ error: 'Konfigurationsdatei nicht gefunden' }), { status: 404 });
+    }
+
+    // Verhindere Löschen der aktiven Homepage
+    if (config.site_info?.homepage_id === page_id) {
+      return new Response(JSON.stringify({ error: 'Die aktive Startseite kann nicht gelöscht werden.' }), { status: 400 });
+    }
+
+    config.pages = (config.pages || []).filter((p: any) => p.id !== page_id);
+
+    await fs.mkdir(DATA_DIR, { recursive: true });
+    await fs.writeFile(configPath, JSON.stringify(config, null, 2), 'utf-8');
+
+    return new Response(JSON.stringify({ success: true, message: 'Seite erfolgreich gelöscht' }), { status: 200 });
+  } catch (error) {
+    return new Response(JSON.stringify({ error: 'Fehler beim Löschen der Seite' }), { status: 500 });
+  }
+};