When designing a form, you should use pixels (px) as the CSS unit, since this is the default unit used by the Form Designer.
The Form Designer performs many operations to automatically adjust the form’s global layout based on the height and width of the form elements. As such, though you can use other CSS units in both the form template stylesheet and appearance mode, this may cause unwanted side effects. We recommend taking this into account when designing your form template stylesheet or editing the appearance of your form.
This applies to all CSS styles with units, including (but not limited to):
- Padding
- Margin
- Width and height
- Font size
- Border width