document.addEventListener('DOMContentLoaded', () => {
    const contactForm = document.getElementById('appointmentForm');
    if (contactForm) {
        contactForm.addEventListener('submit', async (e) => {
            e.preventDefault();
            
            const submitBtn = contactForm.querySelector('button[type="submit"]');
            const originalBtnText = submitBtn.innerHTML;
            
            // Basic UI feedback
            submitBtn.disabled = true;
            submitBtn.innerHTML = '<span class="spinner-border spinner-border-sm" role="status" aria-hidden="true"></span> Sendet...';
            
            const formData = new FormData(contactForm);
            
            try {
                const response = await fetch('api/submit_lead.php', {
                    method: 'POST',
                    body: formData
                });
                
                const result = await response.json();
                
                if (result.success) {
                    alert(result.message);
                    contactForm.reset();
                } else {
                    alert(result.message || 'Ein Fehler ist aufgetreten.');
                }
            } catch (error) {
                console.error('Error:', error);
                alert('Ein Netzwerkfehler ist aufgetreten. Bitte prüfen Sie Ihre Verbindung.');
            } finally {
                submitBtn.disabled = false;
                submitBtn.innerHTML = originalBtnText;
            }
        });
    }
});