How can I align my form labels, input boxes, etc, so the content of my form is centered within the form-all div?

I've already centered my submit button, as in the picture I have attached. How do I center the rest of my form content?

To make the Form content center-aligned add the following code to the custom CSS

ul.form-section.page-section {    
text-align: -webkit-center;
}

.form-label.form-label-auto {    
text-align: center!important;
}

Hope this helps.