diff --git a/components/PageLeaveGuard.vue b/components/PageLeaveGuard.vue
new file mode 100644
index 0000000..af9a563
--- /dev/null
+++ b/components/PageLeaveGuard.vue
@@ -0,0 +1,98 @@
+<script setup lang="ts">
+import { ref, onMounted, onBeforeUnmount } from 'vue'
+import { onBeforeRouteLeave } from 'vue-router'
+
+// Wir erwarten eine Prop, die sagt, ob geschützt werden soll
+const props = defineProps<{
+  when: boolean // z.B. true, wenn Formular dirty ist
+}>()
+
+const showModal = ref(false)
+const pendingNext = ref<null | ((val?: boolean) => void)>(null)
+
+// --- 1. Interne Navigation (Nuxt) ---
+onBeforeRouteLeave((to, from, next) => {
+  if (!props.when) {
+    next()
+    return
+  }
+
+  // Navigation pausieren & Modal zeigen
+  pendingNext.value = next
+  showModal.value = true
+})
+
+const confirmLeave = () => {
+  if (pendingNext.value) pendingNext.value()
+  showModal.value = false
+}
+
+const cancelLeave = () => {
+  showModal.value = false
+  // Navigation wird implizit abgebrochen
+}
+
+// --- 2. Externe Navigation (Browser Tab schließen) ---
+const handleBeforeUnload = (e: BeforeUnloadEvent) => {
+  if (props.when) {
+    e.preventDefault()
+    e.returnValue = ''
+  }
+}
+
+onMounted(() => window.addEventListener('beforeunload', handleBeforeUnload))
+onBeforeUnmount(() => window.removeEventListener('beforeunload', handleBeforeUnload))
+</script>
+
+<template>
+  <Teleport to="body">
+    <div v-if="showModal" class="guard-overlay">
+      <div class="guard-modal">
+
+        <div class="guard-header">
+          <slot name="title">Seite wirklich verlassen?</slot>
+        </div>
+
+        <div class="guard-body">
+          <slot>
+            Du hast ungespeicherte Änderungen. Diese gehen verloren, wenn du die Seite verlässt.
+          </slot>
+        </div>
+
+        <div class="guard-actions">
+          <button @click="cancelLeave" class="btn-cancel">
+            Nein, bleiben
+          </button>
+          <button @click="confirmLeave" class="btn-confirm">
+            Ja, verlassen
+          </button>
+        </div>
+
+      </div>
+    </div>
+  </Teleport>
+</template>
+
+<style scoped>
+/* Basis-Styling - passe dies an dein Design System an */
+.guard-overlay {
+  position: fixed; inset: 0; background: rgba(0,0,0,0.6);
+  display: flex; align-items: center; justify-content: center;
+  z-index: 9999; backdrop-filter: blur(2px);
+}
+.guard-modal {
+  background: white; padding: 24px; border-radius: 12px;
+  width: 90%; max-width: 400px; box-shadow: 0 10px 25px rgba(0,0,0,0.2);
+  font-family: sans-serif;
+}
+.guard-header { font-size: 1.25rem; font-weight: bold; margin-bottom: 1rem; }
+.guard-body { margin-bottom: 1.5rem; color: #4a5568; }
+.guard-actions { display: flex; justify-content: flex-end; gap: 12px; }
+
+/* Buttons */
+button { padding: 8px 16px; border-radius: 6px; cursor: pointer; border: none; font-weight: 600;}
+.btn-cancel { background: #edf2f7; color: #2d3748; }
+.btn-cancel:hover { background: #e2e8f0; }
+.btn-confirm { background: #e53e3e; color: white; }
+.btn-confirm:hover { background: #c53030; }
+</style>
\ No newline at end of file
diff --git a/pages/createDocument/edit/[[id]].vue b/pages/createDocument/edit/[[id]].vue
index 3ba7e88..cb7f612 100644
--- a/pages/createDocument/edit/[[id]].vue
+++ b/pages/createDocument/edit/[[id]].vue
@@ -3136,6 +3136,7 @@ const setRowData = async (row, service = {sellingPriceComposed: {}}, product = {
     </UTabs>
     <UProgress animation="carousel" v-else/>
   </UDashboardPanelContent>
+  <PageLeaveGuard :when="true"/>
 
 
 
diff --git a/pages/incomingInvoices/[mode]/[id].vue b/pages/incomingInvoices/[mode]/[id].vue
index 319fc26..51488ba 100644
--- a/pages/incomingInvoices/[mode]/[id].vue
+++ b/pages/incomingInvoices/[mode]/[id].vue
@@ -575,6 +575,7 @@ const findIncomingInvoiceErrors = computed(() => {
     <UProgress v-else animation="carousel"/>
   </UDashboardPanelContent>
 
+  <PageLeaveGuard :when="true"/>