diff --git a/Website/main.py b/Website/main.py
index b969286..2fb912e 100644
--- a/Website/main.py
+++ b/Website/main.py
@@ -3406,6 +3406,26 @@ def logout():
     flash('Logged out successfully', 'info')
     return redirect(url_for('login'))
 
+@app.route('/booking_payment_async', methods=['POST'])
+def booking_payment_async():
+    # ... Speichere Daten in DB ...
+    # ... Starte das manage-tenants.sh Skript ASYNCHRON (z.B. Celery) ...
+    return jsonify({"success": True, "tenant_slug": request.form['tenant_slug']}), 200
+
+
+@app.route('/instance_request/status')
+def tenant_status():
+    slug = request.args.get('slug')
+    # Prüfe in der Datenbank, ob das Skript für diesen Slug schon fertig ist
+    if ist_fertig(slug):
+        return jsonify({
+            "status": "ready",
+            "url": f"https://{slug}.invario-software.de",
+            "username": "admin",
+            "password": generiertes_passwort
+        })
+    else:
+        return jsonify({"status": "pending"})
 
 def main():
     app.run(host="0.0.0.0", port=4999, debug=False)
diff --git a/Website/templates/schnell_buchung.html b/Website/templates/schnell_buchung.html
index 8e723c3..c375a43 100644
--- a/Website/templates/schnell_buchung.html
+++ b/Website/templates/schnell_buchung.html
@@ -1,6 +1,6 @@
 {% extends "base.html" %}
 
-{% block title %}Buchung prüfen{% endblock %}
+{% block title %}Buchung prüfen & abschließen{% endblock %}
 
 {% block head %}
 {{ super() }}
@@ -17,6 +17,8 @@
         border-radius: 26px;
         padding: clamp(1.4rem, 2.6vw, 2.2rem);
         box-shadow: 0 18px 44px rgba(18, 49, 54, 0.08);
+        position: relative;
+        overflow: hidden;
     }
 
     .booking-review__eyebrow {
@@ -31,11 +33,6 @@
         margin-bottom: 1rem;
     }
 
-    .booking-review__lead {
-        margin-top: 0.75rem;
-        max-width: 66ch;
-    }
-
     .booking-review__grid {
         display: grid;
         grid-template-columns: repeat(2, minmax(0, 1fr));
@@ -54,7 +51,6 @@
         display: block;
         font-size: 0.88rem;
         font-weight: 700;
-        letter-spacing: 0.03em;
         text-transform: uppercase;
         color: #5e757d;
         margin-bottom: 0.45rem;
@@ -75,12 +71,24 @@
         line-height: 1.65;
     }
 
+    /* Formular Styles */
     .booking-review__form-grid {
         display: grid;
         grid-template-columns: repeat(2, minmax(0, 1fr));
         gap: 0.9rem;
         margin-top: 1.25rem;
     }
+    
+    .booking-review__section-title {
+        grid-column: 1 / -1;
+        font-size: 1.15rem;
+        color: #166271;
+        margin-top: 1.5rem;
+        margin-bottom: 0.2rem;
+        border-bottom: 2px solid #e8f4f4;
+        padding-bottom: 0.5rem;
+        font-weight: 700;
+    }
 
     .booking-review__field {
         display: flex;
@@ -98,18 +106,34 @@
         font-size: 0.93rem;
     }
 
-    .booking-review__field input,
-    .booking-review__field textarea {
+    .booking-review__field input {
         border: 1px solid #cedbdd;
         border-radius: 12px;
         background: #ffffff;
         color: #173a42;
         padding: 0.75rem 0.82rem;
     }
-
-    .booking-review__field textarea {
-        min-height: 110px;
-        resize: vertical;
+    
+    .input-group--subdomain {
+        display: flex;
+        align-items: center;
+    }
+    
+    .input-group--subdomain input {
+        border-top-right-radius: 0;
+        border-bottom-right-radius: 0;
+        border-right: none;
+        flex-grow: 1;
+    }
+    
+    .input-group--subdomain .domain-suffix {
+        background: #e8f4f4;
+        border: 1px solid #cedbdd;
+        padding: 0.75rem 0.82rem;
+        border-top-right-radius: 12px;
+        border-bottom-right-radius: 12px;
+        color: #5e757d;
+        font-weight: 600;
     }
 
     .booking-review__consent {
@@ -130,13 +154,6 @@
 
     .booking-review__consent input {
         margin-top: 0.2rem;
-        width: auto;
-        flex: 0 0 auto;
-    }
-
-    .booking-review__consent a {
-        color: #0a4c74;
-        text-decoration: underline;
     }
 
     .booking-review__actions {
@@ -146,26 +163,78 @@
         margin-top: 1.5rem;
     }
 
-    .booking-review__actions .btn,
-    .booking-review__actions a {
-        width: auto;
-        min-width: 190px;
+    /* NEU: Loading State UI */
+    #setup-loading-state,
+    #setup-success-state {
+        display: none;
+        text-align: center;
+        padding: 3rem 1rem;
+    }
+
+    .spinner {
+        width: 60px;
+        height: 60px;
+        border: 5px solid #e8f4f4;
+        border-top-color: #166271;
+        border-radius: 50%;
+        animation: spin 1s linear infinite;
+        margin: 0 auto 2rem;
+    }
+
+    @keyframes spin { 100% { transform: rotate(360deg); } }
+
+    .status-messages {
+        font-size: 1.1rem;
+        color: #49626b;
+        font-weight: 600;
+        height: 2rem;
+    }
+
+    /* NEU: Success State UI */
+    .success-icon {
+        width: 70px;
+        height: 70px;
+        background: #1b8a3e;
+        color: white;
+        border-radius: 50%;
+        display: flex;
+        align-items: center;
+        justify-content: center;
+        font-size: 2rem;
+        margin: 0 auto 1.5rem;
+    }
+
+    .credentials-box {
+        background: #173a42;
+        color: white;
+        border-radius: 12px;
+        padding: 1.5rem;
+        margin: 1.5rem auto;
+        max-width: 400px;
+        text-align: left;
+    }
+
+    .credentials-box code {
+        display: block;
+        background: rgba(255,255,255,0.1);
+        padding: 0.5rem;
+        border-radius: 6px;
+        margin-top: 0.3rem;
+        font-size: 1.1rem;
+        user-select: all;
+    }
+
+    .warning-text {
+        color: #b02a37;
+        font-weight: 700;
+        background: #f8d7da;
+        padding: 1rem;
+        border-radius: 8px;
+        margin-bottom: 1.5rem;
     }
 
     @media (max-width: 720px) {
-        .booking-review__grid {
-            grid-template-columns: 1fr;
-        }
-
-        .booking-review__form-grid {
-            grid-template-columns: 1fr;
-        }
-
-        .booking-review__actions .btn,
-        .booking-review__actions a {
-            width: 100%;
-            min-width: 0;
-        }
+        .booking-review__grid, .booking-review__form-grid { grid-template-columns: 1fr; }
     }
 </style>
 {% endblock %}
@@ -173,123 +242,278 @@
 {% block content %}
 <section class="booking-review">
     <div class="booking-review__panel">
-        <span class="booking-review__eyebrow">Buchung prüfen</span>
-        <h1>{{ title }}</h1>
-        <p class="booking-review__lead">{{ intro }}</p>
+        
+        <!-- ========================================== -->
+        <!-- STATE 1: FORMULAR (Checkout)               -->
+        <!-- ========================================== -->
+        <div id="checkout-form-state">
+            <span class="booking-review__eyebrow">Buchung prüfen & abschließen</span>
+            <h1>{{ title }}</h1>
+            
+            <div class="booking-review__grid">
+                <div class="booking-review__card">
+                    <span class="booking-review__label">Paket</span>
+                    <div class="booking-review__value">{{ package }}</div>
+                </div>
+                <div class="booking-review__card">
+                    <span class="booking-review__label">Preis</span>
+                    <div class="booking-review__value">{{ package_price }} € <br><small>Kauf auf Rechnung (30 Tage)</small></div>
+                </div>
+            </div>
 
-        <div class="booking-review__grid" aria-label="Buchungsübersicht">
-            <div class="booking-review__card">
-                <span class="booking-review__label">Paket</span>
-                <div class="booking-review__value">{{ package }}</div>
-            </div>
-            <div class="booking-review__card">
-                <span class="booking-review__label">Preis</span>
-                <div class="booking-review__value">{{ package_price }} €</div>
-            </div>
-            <div class="booking-review__card">
-                <span class="booking-review__label">Angemeldet als</span>
-                <div class="booking-review__value">{{ display_name }}</div>
+            <div class="booking-review__note">
+                Die Software-Instanz wird nach dem Absenden <strong>sofort für 30 Tage freigeschaltet</strong>. Die finale Laufzeit aktiviert sich automatisch nach Zahlungseingang durch Ihren Schulträger.
             </div>
+
+            <!-- Das Formular schickt die Daten an /booking_payment_async -->
+            <form id="checkout-form" method="POST" action="{{ url_for('booking_payment_async') }}">
+                <input type="hidden" name="package" value="{{ package_key }}">
+                
+                <div class="booking-review__form-grid">
+                    <div class="booking-review__section-title">1. Angaben zur Schule & Ansprechpartner</div>
+                    <div class="booking-review__field">
+                        <label for="school_name">Name der Schule *</label>
+                        <input id="school_name" name="school_name" type="text" required value="{{ form_data.school_name }}">
+                    </div>
+                    <div class="booking-review__field">
+                        <label for="school_number">Dienststellennummer *</label>
+                        <input id="school_number" name="school_number" type="text" required placeholder="Zur Legitimation" value="{{ form_data.school_number }}">
+                    </div>
+                    <div class="booking-review__field">
+                        <label for="contact_person">Ansprechpartner *</label>
+                        <input id="contact_person" name="contact_person" type="text" required value="{{ form_data.contact_person }}">
+                    </div>
+                    <div class="booking-review__field">
+                        <label for="contact_email">Dienstliche E-Mail *</label>
+                        <input id="contact_email" name="contact_email" type="email" required value="{{ form_data.contact_email }}">
+                    </div>
+
+                    <div class="booking-review__section-title">2. Rechnungsadresse (Schulträger)</div>
+                    <div class="booking-review__field booking-review__field--full">
+                        <label for="billing_organization">Einrichtung / Amt *</label>
+                        <input id="billing_organization" name="billing_organization" type="text" required value="{{ form_data.billing_organization }}">
+                    </div>
+                    <div class="booking-review__field booking-review__field--full">
+                        <label for="billing_street">Straße & Hausnummer *</label>
+                        <input id="billing_street" name="billing_street" type="text" required value="{{ form_data.billing_street }}">
+                    </div>
+                    <div class="booking-review__field">
+                        <label for="billing_zip">PLZ *</label>
+                        <input id="billing_zip" name="billing_zip" type="text" required value="{{ form_data.billing_zip }}">
+                    </div>
+                    <div class="booking-review__field">
+                        <label for="billing_city">Ort *</label>
+                        <input id="billing_city" name="billing_city" type="text" required value="{{ form_data.billing_city }}">
+                    </div>
+
+                    <div class="booking-review__section-title">3. Technische Einrichtung</div>
+                    <div class="booking-review__field booking-review__field--full">
+                        <label for="tenant_slug">Gewünschte Schul-URL *</label>
+                        <div class="input-group--subdomain">
+                            <input id="tenant_slug" name="tenant_slug" type="text" required pattern="[a-z0-9-]+" placeholder="gymnasium-neustadt" value="{{ form_data.tenant_slug }}">
+                            <span class="domain-suffix">.euresoftware.de</span>
+                        </div>
+                        <div id="tenant_slug_feedback" style="margin-top:0.4rem; font-size:0.9rem; font-weight:600;"></div>
+                    </div>
+
+                    <div class="booking-review__field booking-review__field--full booking-review__consent">
+                        <label for="agreements_accepted">
+                            <input id="agreements_accepted" name="agreements_accepted" type="checkbox" required>
+                            <span>Ich habe die Nutzungsbedingungen und den obligatorischen AVV gelesen und stimme diesen verbindlich zu.</span>
+                        </label>
+                    </div>
+                </div>
+
+                <!-- Fehleranzeige, falls der Server beim Submit meckert -->
+                <div id="form-error-alert" style="display:none; color:#b02a37; margin-top:1rem; font-weight:bold;"></div>
+
+                <div class="booking-review__actions">
+                    <button id="booking_submit" class="btn" type="submit">Kostenpflichtig buchen & Instanz starten</button>
+                </div>
+            </form>
         </div>
 
-        <div class="booking-review__note">
-            Bitte prüfen Sie die Angaben noch einmal. Wenn alles korrekt ist, senden sie ihre Informationen mit dem folgenden Button an uns, wir senden ihnen frühstmöglich eine Rechnung per Email.
+        <!-- ========================================== -->
+        <!-- STATE 2: LOADING (Asynchrones Setup)       -->
+        <!-- ========================================== -->
+        <div id="setup-loading-state">
+            <h2>Instanz wird bereitgestellt</h2>
+            <p>Ihre Bestellung war erfolgreich. Die Rechnung wird gerade verschickt.</p>
+            <div class="spinner"></div>
+            <div class="status-messages" id="loading-status-text">Validierung der Daten...</div>
+            <p style="margin-top: 2rem; color: #5e757d; font-size: 0.9rem;">Bitte schließen Sie dieses Fenster nicht. Dies dauert in der Regel 15-30 Sekunden.</p>
         </div>
 
-        <form method="POST" action="{{ url_for('booking_payment') }}">
-            <input type="hidden" name="package" value="{{ package_key }}">
-            <input type="hidden" name="flow" value="{{ flow }}">
-
-            <div class="booking-review__form-grid" aria-label="Pflichtdaten für Buchung">
-                <div class="booking-review__field">
-                    <label for="contact_person">Ansprechpartner *</label>
-                    <input id="contact_person" name="contact_person" type="text" required maxlength="120" value="{{ form_data.contact_person }}">
-                </div>
-                <div class="booking-review__field">
-                    <label for="school_name">Schule/Einrichtung *</label>
-                    <input id="school_name" name="school_name" type="text" required maxlength="160" value="{{ form_data.school_name }}">
-                    <div id="school_name_feedback" style="margin-top:0.4rem; font-size:0.9rem; color:#6b6b6b;"></div>
-                </div>
-                <div class="booking-review__field">
-                    <label for="contact_email">E-Mail *</label>
-                    <input id="contact_email" name="contact_email" type="email" required maxlength="160" value="{{ form_data.contact_email }}">
-                </div>
-                <div class="booking-review__field">
-                    <label for="contact_phone">Telefon</label>
-                    <input id="contact_phone" name="contact_phone" type="text" maxlength="60" value="{{ form_data.contact_phone }}">
-                </div>
-                <div class="booking-review__field booking-review__field--full">
-                    <label for="billing_street">Straße *</label>
-                    <input id="billing_street" name="billing_street" type="text" required maxlength="160" value="{{ form_data.billing_street }}">
-                </div>
-                <div class="booking-review__field">
-                    <label for="billing_zip">PLZ *</label>
-                    <input id="billing_zip" name="billing_zip" type="text" required maxlength="20" value="{{ form_data.billing_zip }}">
-                </div>
-                <div class="booking-review__field">
-                    <label for="billing_city">Ort *</label>
-                    <input id="billing_city" name="billing_city" type="text" required maxlength="120" value="{{ form_data.billing_city }}">
-                </div>
-                <div class="booking-review__field booking-review__field--full">
-                    <label for="notes">Zusatzinformationen</label>
-                    <textarea id="notes" name="notes" maxlength="600" placeholder="Optional: gewünschter Starttermin, besondere Anforderungen, Rückrufzeiten">{{ form_data.notes }}</textarea>
-                </div>
-                <div class="booking-review__field booking-review__field--full booking-review__consent">
-                    <label for="agreements_accepted">
-                        <input id="agreements_accepted" name="agreements_accepted" type="checkbox" value="yes" required {% if form_data.agreements_accepted %}checked{% endif %}>
-                        <span>Ich habe die <a href="{{ url_for('nutzungsbedingungen') }}" target="_blank" rel="noopener">Lizenzvereinbarung</a>, die <a href="{{ url_for('datenschutz') }}" target="_blank" rel="noopener">Datenschutzerklärung</a> und die DSGVO-Hinweise gelesen und akzeptiere sie.</span>
-                    </label>
-                </div>
+        <!-- ========================================== -->
+        <!-- STATE 3: SUCCESS (Bereit zur Nutzung)      -->
+        <!-- ========================================== -->
+        <div id="setup-success-state">
+            <div class="success-icon">✓</div>
+            <h2>Ihre Schule ist online!</h2>
+            <p>Das Setup wurde erfolgreich abgeschlossen. Sie können sich nun einloggen.</p>
+            
+            <div class="warning-text">
+                Aus Datenschutzgründen (AVV) müssen Sie das generierte Passwort nach dem ersten Login zwingend ändern!
             </div>
 
-            <div class="booking-review__actions">
-                <button id="booking_submit" class="btn" type="submit">{{ confirm_label }}</button>
-                <a class="btn secondary" href="{{ url_for('preise') }}">Zurück zu den Preisen</a>
+            <div class="credentials-box">
+                <p><strong>Login-URL:</strong> <br><a id="success-url" href="#" target="_blank" style="color: #66d9e8;">-</a></p>
+                <p><strong>Benutzername (Admin):</strong> <code id="success-user">-</code></p>
+                <p><strong>Initial-Passwort:</strong> <code id="success-pass">-</code></p>
             </div>
-        </form>
+
+            <a id="btn-go-to-tenant" href="#" class="btn" target="_blank" style="width: 100%; max-width: 400px;">Jetzt zur Schulplattform wechseln</a>
+        </div>
+
     </div>
 </section>
+
 <script>
 (() => {
-    const input = document.getElementById('school_name');
-    const feedback = document.getElementById('school_name_feedback');
-    const submit = document.getElementById('booking_submit');
-    let timer = null;
+    // DOM Elemente
+    const formState = document.getElementById('checkout-form-state');
+    const loadingState = document.getElementById('setup-loading-state');
+    const successState = document.getElementById('setup-success-state');
+    
+    const form = document.getElementById('checkout-form');
+    const errorAlert = document.getElementById('form-error-alert');
+    const statusText = document.getElementById('loading-status-text');
+    
+    // Subdomain Live-Prüfung
+    const slugInput = document.getElementById('tenant_slug');
+    const feedback = document.getElementById('tenant_slug_feedback');
+    const submitBtn = document.getElementById('booking_submit');
+    let slugTimer = null;
 
-    function setFeedback(text, ok) {
-        feedback.textContent = text;
-        feedback.style.color = ok ? '#1b8a3e' : '#b02a37';
-        submit.disabled = !ok;
-    }
+    slugInput.addEventListener('input', (e) => {
+        e.target.value = e.target.value.toLowerCase().replace(/[^a-z0-9-]/g, '');
+    });
 
-    async function check(name) {
-        if (!name || name.trim().length < 3) {
-            feedback.textContent = '';
-            submit.disabled = false;
-            return;
-        }
+    slugInput.addEventListener('keyup', (e) => {
+        clearTimeout(slugTimer);
+        slugTimer = setTimeout(() => checkSubdomain(e.target.value), 600);
+    });
+
+    async function checkSubdomain(name) {
+        if (name.length < 3) return;
         try {
-            const params = new URLSearchParams({ school_name: name });
-            const res = await fetch(`/instance_request/check_subdomain?${params.toString()}`, { credentials: 'same-origin' });
-            if (!res.ok) throw new Error('Netzwerkfehler');
+            const res = await fetch(`/instance_request/check_subdomain?slug=${name}`);
             const j = await res.json();
-            setFeedback(j.message || (j.available ? 'verfügbar' : 'nicht verfügbar'), !!j.available);
+            if (j.available) {
+                feedback.textContent = 'Adresse ist frei!';
+                feedback.style.color = '#1b8a3e';
+                submitBtn.disabled = false;
+            } else {
+                feedback.textContent = 'Adresse ist bereits vergeben.';
+                feedback.style.color = '#b02a37';
+                submitBtn.disabled = true;
+            }
         } catch (e) {
-            setFeedback('Prüfung fehlgeschlagen (Netzwerk).', false);
+            console.error(e);
         }
     }
 
-    if (input) {
-        input.addEventListener('input', (e) => {
-            clearTimeout(timer);
-            const val = e.target.value;
-            timer = setTimeout(() => check(val), 500);
-        });
+    // ==========================================
+    // AJAX Form Submit & Transition to Loading
+    // ==========================================
+    form.addEventListener('submit', async (e) => {
+        e.preventDefault(); // Verhindert das klassische Neuladen der Seite
+        errorAlert.style.display = 'none';
+        submitBtn.disabled = true;
 
-        // initial check on load
-        if (input.value && input.value.trim()) {
-            check(input.value);
+        const formData = new FormData(form);
+        const tenantSlug = formData.get('tenant_slug');
+
+        try {
+            // 1. Schicke Daten ans Backend (muss im Backend JSON zurückgeben!)
+            const response = await fetch(form.action, {
+                method: 'POST',
+                body: formData,
+                headers: { 'Accept': 'application/json' }
+            });
+
+            const result = await response.json();
+
+            if (!response.ok) {
+                throw new Error(result.error || 'Es gab ein Problem bei der Buchung.');
+            }
+
+            // 2. Erfolg: Formular verstecken, Ladebildschirm zeigen
+            formState.style.display = 'none';
+            loadingState.style.display = 'block';
+
+            // 3. Starte Polling
+            startPolling(tenantSlug);
+
+        } catch (error) {
+            errorAlert.textContent = error.message;
+            errorAlert.style.display = 'block';
+            submitBtn.disabled = false;
         }
+    });
+
+    // ==========================================
+    // Polling Logik (Warten auf den Server)
+    // ==========================================
+    async function startPolling(slug) {
+        // Fake-Texte für den Nutzer, damit er weiß, dass das System arbeitet
+        const statusMessages = [
+            "Prüfe Serverkapazitäten...",
+            "Richte Datenbank ein...",
+            "Konfiguriere Nginx & Zertifikate...",
+            "Führe finale Health-Checks durch..."
+        ];
+        
+        let msgIndex = 0;
+        const msgInterval = setInterval(() => {
+            if (msgIndex < statusMessages.length) {
+                statusText.textContent = statusMessages[msgIndex];
+                msgIndex++;
+            }
+        }, 3500);
+
+        // Das eigentliche Polling zum Backend
+        const checkStatus = async () => {
+            try {
+                // Backend-Route, die den Status des tenant_slug abfragt
+                const res = await fetch(`/instance_request/status?slug=${slug}`);
+                const data = await res.json();
+
+                if (data.status === 'ready') {
+                    // SETUP FERTIG!
+                    clearInterval(msgInterval);
+                    showSuccessState(data.url, data.username, data.password);
+                } else if (data.status === 'failed') {
+                    // SETUP FEHLGESCHLAGEN
+                    clearInterval(msgInterval);
+                    statusText.textContent = "Fehler bei der Bereitstellung. Bitte Support kontaktieren.";
+                    statusText.style.color = '#b02a37';
+                } else {
+                    // SETUP LÄUFT NOCH -> in 3 Sekunden erneut prüfen
+                    setTimeout(checkStatus, 3000);
+                }
+            } catch (err) {
+                // Bei Netzwerkfehlern während des Pollings einfach weiter probieren
+                setTimeout(checkStatus, 3000);
+            }
+        };
+
+        // Starte den ersten Check nach 2 Sekunden
+        setTimeout(checkStatus, 2000);
+    }
+
+    // ==========================================
+    // Erfolgs-Bildschirm anzeigen
+    // ==========================================
+    function showSuccessState(url, user, pass) {
+        loadingState.style.display = 'none';
+        successState.style.display = 'block';
+
+        document.getElementById('success-url').textContent = url;
+        document.getElementById('success-url').href = url;
+        document.getElementById('success-user').textContent = user;
+        document.getElementById('success-pass').textContent = pass;
+        document.getElementById('btn-go-to-tenant').href = url;
     }
 })();
 </script>