In the "Form Settings" editor, there are two customization categories: "General" and "Look & Feel".
The settings we are interested in are located under the "Look & Feel" tab.
Step 2 - change styles
For the Form element there are the following available styling options:
1. Field Box Style
Use the "Field Box Style" dropdown to customize the appearance of the form input fields.
In this dropdown, you have all the predefined styles in "Website Look & Feel -> Box Styles". You can select one of the predefined styles.
If you want to edit an existing style or create your own style, click on the "Edit Style" button which will open the "Website Look & Feel -> Box Styles" sidebar.