diff --git a/web/index.html b/web/index.html
index daf4bd7..848e20e 100644
--- a/web/index.html
+++ b/web/index.html
@@ -49,6 +49,32 @@
   <!-- Toast -->
   <div class="toast" id="toast"></div>
 
+  <!-- Tune Modal -->
+  <div class="modal-overlay" id="tune-modal" role="dialog" aria-label="Prompt tunen">
+    <div class="modal" style="max-width: 1200px;">
+      <div class="modal-header">
+        <h2 id="tune-title">Prompt tunen</h2>
+        <button class="modal-close" onclick="closeTuneModal()">&times;</button>
+      </div>
+      <div class="modal-body" id="tune-content" style="display: flex; flex-direction: column; gap: 16px; min-height: 400px; overflow-y: auto;"></div>
+      <div class="modal-actions">
+        <button class="btn btn-primary" id="tune-generate-btn" onclick="generateTunedTemplate()">
+          <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+            <path d="M12 2v4m0 12v4m8-8h-4M6 12H2m14.5-7.5L16 5.5m-8 8L5.5 16m13-10.5L16 8m-8 8L5.5 16"/>
+          </svg>
+          Generieren
+        </button>
+        <button class="btn" id="tune-apply-btn" onclick="applyTunedContent()" style="display:none;">
+          <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+            <path d="M20 6L9 17l-5-5"/>
+          </svg>
+          Übernehmen
+        </button>
+        <button class="btn" onclick="closeTuneModal()">Schließen</button>
+      </div>
+    </div>
+  </div>
+
   <div class="header">
     <h1>Prompt Templates</h1>
     <span class="badge">Git Managed</span>
diff --git a/web/js/editor.js b/web/js/editor.js
index 2528a02..6ac25ca 100644
--- a/web/js/editor.js
+++ b/web/js/editor.js
@@ -295,6 +295,235 @@ function extractJsonFromForm(formDiv) {
   return result;
 }
 
+/**
+ * LLM-API-Konfiguration (llama.cpp / Kilo-Instanz)
+ */
+const LLM_BASE = 'http://localhost:8001/v1';
+const LLM_MODEL = 'Qwen3.6-35B-A3B-UD-Q3_K_S.gguf';
+
+/**
+ * Zustand für den Tunen-Dialog
+ */
+window._tuneState = { path: '', rawPath: '', template: '' };
+
+/**
+ * Öffne Tune-Modal für eine Template-Datei
+ * @param {string} path - Pfad zur Template-Datei
+ */
+function tuneModalContent(path) {
+  window._tuneState.path = path;
+  window._tuneState.rawPath = '';
+  window._tuneState.template = '';
+  window._tuneState.generated = '';
+
+  const title = path.split('/').pop();
+  document.getElementById('tune-title').textContent = `Prompt tunen: ${title}`;
+
+  // Generate-Button aktivieren, Apply-Button verstecken
+  document.getElementById('tune-generate-btn').style.display = '';
+  document.getElementById('tune-apply-btn').style.display = 'none';
+  document.getElementById('tune-generate-btn').disabled = false;
+  document.getElementById('tune-generate-btn').innerHTML = `
+    <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+      <path d="M12 2v4m0 12v4m8-8h-4M6 12H2m14.5-7.5L16 5.5m-8 8L5.5 16m13-10.5L16 8m-8 8L5.5 16"/>
+    </svg>
+    Generieren`;
+
+  const container = document.getElementById('tune-content');
+  container.innerHTML = '<div style="text-align:center;padding:40px;color:var(--text-muted)">Lade Template...</div>';
+  document.getElementById('tune-modal').classList.add('active');
+
+  fetch(path)
+    .then(r => r.json())
+    .then(data => {
+      window._tuneState.template = data.template || '';
+      renderTuneUI(window._tuneState);
+    })
+    .catch(e => {
+      container.innerHTML = `<div style="color:var(--text-error);text-align:center;padding:20px">✗ Fehler: ${e.message}</div>`;
+    });
+}
+
+/**
+ * Render die Tune-UI mit Original-Template und Preprompt
+ * @param {Object} state - Tune-Zustand
+ */
+function renderTuneUI(state) {
+  const container = document.getElementById('tune-content');
+  container.innerHTML = '';
+
+  // Original-Template
+  const originalPanel = document.createElement('div');
+  originalPanel.style.cssText = 'display:flex;flex-direction:column;gap:6px;';
+  const origLabel = document.createElement('label');
+  origLabel.style.cssText = 'font-weight:600;font-size:13px;color:var(--text-secondary);';
+  origLabel.textContent = 'Original-Template';
+  originalPanel.appendChild(origLabel);
+
+  const origTextarea = document.createElement('textarea');
+  origTextarea.id = 'tune-original';
+  origTextarea.value = state.template;
+  origTextarea.readOnly = true;
+  origTextarea.style.cssText = 'width:100%;min-height:200px;padding:10px;background:var(--bg-input);color:var(--text-primary);border:1px solid var(--border);border-radius:4px;font-family:var(--mono);font-size:13px;resize:vertical;';
+  originalPanel.appendChild(origTextarea);
+  container.appendChild(originalPanel);
+
+  // Preprompt-Feld
+  const prepromptPanel = document.createElement('div');
+  prepromptPanel.style.cssText = 'display:flex;flex-direction:column;gap:6px;';
+  const prepromptLabel = document.createElement('label');
+  prepromptLabel.style.cssText = 'font-weight:600;font-size:13px;color:var(--text-secondary);';
+  prepromptLabel.textContent = 'Preprompt (deine Wünsche zur Verbesserung)';
+  prepromptPanel.appendChild(prepromptLabel);
+
+  const prepromptTextarea = document.createElement('textarea');
+  prepromptTextarea.id = 'tune-preprompt';
+  prepromptTextarea.style.cssText = 'width:100%;min-height:80px;padding:10px;background:var(--bg-input);color:var(--text-primary);border:1px solid var(--border);border-radius:4px;font-family:var(--mono);font-size:13px;resize:vertical;';
+  prepromptTextarea.placeholder = 'z.B. Mach das Template kürzer, füge Security-Checks hinzu, verwende einen professionelleren Ton...';
+  prepromptPanel.appendChild(prepromptTextarea);
+  container.appendChild(prepromptPanel);
+
+  // Ergebnis-Panel (initial versteckt)
+  const resultPanel = document.createElement('div');
+  resultPanel.id = 'tune-result-panel';
+  resultPanel.style.cssText = 'display:none;flex-direction:column;gap:6px;';
+  const resultLabel = document.createElement('label');
+  resultLabel.style.cssText = 'font-weight:600;font-size:13px;color:var(--text-secondary);';
+  resultLabel.textContent = 'Generiertes Template';
+  resultPanel.appendChild(resultLabel);
+
+  const resultTextarea = document.createElement('textarea');
+  resultTextarea.id = 'tune-result';
+  resultTextarea.readOnly = true;
+  resultTextarea.style.cssText = 'width:100%;min-height:200px;padding:10px;background:var(--bg-input);color:var(--text-primary);border:1px solid var(--border);border-radius:4px;font-family:var(--mono);font-size:13px;resize:vertical;';
+  resultPanel.appendChild(resultTextarea);
+  container.appendChild(resultPanel);
+}
+
+/**
+ * Sende Preprompt + Template an LLM und zeige Ergebnis
+ */
+async function generateTunedTemplate() {
+  const preprompt = document.getElementById('tune-preprompt').value.trim();
+  const original = document.getElementById('tune-original').value;
+
+  if (!preprompt) {
+    showToast('✗ Bitte Preprompt eingeben');
+    return;
+  }
+
+  const btn = document.getElementById('tune-generate-btn');
+  btn.disabled = true;
+  btn.innerHTML = '⏳ Generiere...';
+
+  const resultPanel = document.getElementById('tune-result-panel');
+  const resultTextarea = document.getElementById('tune-result');
+  resultPanel.style.display = 'flex';
+  resultTextarea.value = 'Warte auf Generierung...';
+
+  const systemPrompt = 'Du bist ein Experte für Prompt-Engineering. Du erhältst ein vorhandenes Template und Verbesserungswünsche. Gib NUR das verbesserte Template zurück. Keine Erklärungen, keine Markdown-Codeblöcke, keine Zitatzeichen. Nur den reinen Template-Text.';
+
+  const userPrompt = `Verbessere dieses Template basierend auf den folgenden Anweisungen:
+
+=== Vorhandenes Template ===
+${original}
+
+=== Verbesserungswünsche ===
+${preprompt}
+
+Gib das verbesserte Template zurück.`;
+
+  try {
+    const response = await fetch(`${LLM_BASE}/chat/completions`, {
+      method: 'POST',
+      headers: {'Content-Type': 'application/json'},
+      body: JSON.stringify({
+        model: LLM_MODEL,
+        messages: [
+          { role: 'system', content: systemPrompt },
+          { role: 'user', content: userPrompt }
+        ],
+        stream: false,
+        temperature: 0.7,
+        max_tokens: 2048
+      })
+    });
+
+    if (!response.ok) throw new Error(`HTTP ${response.status}`);
+
+    const data = await response.json();
+    let generated = data.choices?.[0]?.message?.content || '';
+
+    // Bereinige Markdown-Codeblöcke falls vorhanden
+    generated = generated.replace(/^```(?:markdown|text)?\s*\n?/i, '').replace(/\n```$/, '');
+    generated = generated.trim();
+
+    window._tuneState.generated = generated;
+    resultTextarea.value = generated || '(Leer - nothing generated)';
+
+    // Ergebnis-Panel hervorheben und einblenden
+    resultPanel.style.border = '1px solid var(--accent)';
+    resultPanel.style.transition = 'border-color 0.3s';
+    document.getElementById('tune-apply-btn').style.display = '';
+    resultPanel.scrollIntoView({ behavior: 'smooth', block: 'center' });
+    showToast('✓ Template generiert');
+  } catch (e) {
+    resultTextarea.value = `Fehler: ${e.message}\n\nStelle sicher, dass der llama.cpp Server auf ${LLM_BASE} läuft.`;
+    showToast(`✗ ${e.message}`);
+  } finally {
+    btn.disabled = false;
+    btn.innerHTML = `
+      <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+        <path d="M12 2v4m0 12v4m8-8h-4M6 12H2m14.5-7.5L16 5.5m-8 8L5.5 16m13-10.5L16 8m-8 8L5.5 16"/>
+      </svg>
+      Generieren`;
+  }
+}
+
+/**
+ * Generiertes Template übernehmen (ersetzt template-Feld im JSON)
+ */
+async function applyTunedContent() {
+  const state = window._tuneState;
+  const generated = document.getElementById('tune-result').value;
+
+  if (!generated || generated.startsWith('Fehler:') || generated.startsWith('Leer')) {
+    showToast('✗ Kein gültiges Ergebnis zum Übernehmen');
+    return;
+  }
+
+  try {
+    const response = await fetch(state.path);
+    if (!response.ok) throw new Error('Konnte Template nicht laden');
+
+    const data = await response.json();
+    data.template = generated;
+
+    const saveResponse = await fetch(state.path, {
+      method: 'PUT',
+      headers: {'Content-Type': 'text/plain'},
+      body: JSON.stringify(data, null, 2)
+    });
+
+    if (saveResponse.ok) {
+      showToast('✓ Template übernommen und gespeichert');
+      closeTuneModal();
+    } else {
+      throw new Error(`HTTP ${saveResponse.status}`);
+    }
+  } catch (e) {
+    showToast(`✗ Fehler beim Speichern: ${e.message}`);
+  }
+}
+
+/**
+ * Schließe Tune-Modal
+ */
+function closeTuneModal() {
+  document.getElementById('tune-modal').classList.remove('active');
+  window._tuneState = { path: '', rawPath: '', template: '' };
+}
+
 // Export for api.js (global scope, loaded before api.js)
 // editModalContent, createTextEditUI, createJsonEditUI, extractInputValue, extractJsonFromForm
 // sind als globale Funktionen verfügbar
diff --git a/web/js/templates.js b/web/js/templates.js
index ba6c7d5..baba283 100644
--- a/web/js/templates.js
+++ b/web/js/templates.js
@@ -37,6 +37,7 @@ function renderTemplates(templates) {
         <button class="btn btn-icon" onclick="viewTemplate('${esc(t.path)}')">Anzeigen</button>
         <button class="btn btn-icon" onclick="editModalContent('${esc(t.path)}')">📝 Bearbeiten</button>
         <button class="btn btn-icon" onclick="copyContent('${esc(t.path)}')">Inhalt kopieren</button>
+        <button class="btn btn-icon" onclick="tuneModalContent('${esc(t.path)}')">🎯 Tunen</button>
       </div>
     </div>
   `).join('');