This one if particularly for the developers and tech-fans amongst you. Usually your form builder plugin will add very little style of its own by default. Instead it will inherit the styling of yourWordPress theme.
However, sometimes the most perfect theme for your WP website leaves you forms looking a bit off. Showing the confirmation message about 8px too high or the example text in green. That’s when customized CSS comes in very handy. It can also help you give your WordPress forms a very personal touch.
This is why your form builder plugin of choice should have an option to add HTML or CSS. If you’re not familiar with CSS you should definitely hire a developer instead of trying to add it yourself. With CSS you can style the appearance of all form elements by adding custom classes.