This image shows the Stylesheet page where you can apply, upload and preview a stylesheet.

On the left, there is the Properties pane with the different settings on its various fields. Below the Properties pane is the Data pane with the data attributes of the controls on your form.

On the right, is the CSS browser page. The left section of the CSS browser page displays the available Stylesheet and the Upload button. The right section shows the Preview pane with two tabs - CSS and Form. The Form tab is selected and the previewed form is displayed in the Preview pane.