Customize CMS login

Does anyone know where I can edit this part of the registration form?
I need to create a close button and improve the CSS

Were you able to find out how to make this modification? I have the same problem.

Hello @dyogo.nascimento.

There is no specific file to customize this registration popup. However, it is possible to customize it by targeting the element classes and applying styles. To do this, simply add the CSS code lines to one of the style files used in the store, as shown in the example below: