Hey Conte,
Our products do not currently have a form styler so styling forms should be done using custom CSS or other third-party plugins. Using either of them should work but there are 2 factors that will not make them work and that is if you have syntax errors in your CSS or you’re targeting the wrong selectors or you have an aggressive caching plugin or server cache.
If you’re using optimization plugins, you first need to clear all caches and deactivate them to ensure they will not cause issues.
To find the correct selectors to use for CSS, you can use the browser’s developer tools. Below is an article for Chrome.
To check if your custom CSS contains syntax errors, you can use a CSS validator like the site below.
You will then need to contact Gravity Forms to learn how to style their forms. I did a quick search and found this article which might be useful for you.
If the issue persists, please consult with a third-party developer because we do not offer support for third-party plugins and we also do not fix issues arising from the use of custom code.
Thank you for understanding.