I’ve found it!. Thanks for your message. Ummmm I am going to hide some specific fields on one specific page. Would you still recommend me to write code on Custom CSS rather directly on the theme’s CSS file.
@vanesa Please write your additional css in the custom css so that you won’t lose the changes when you update the theme. If you directly make customization to the theme file you will lose the changes when you update the theme. So, using custom css option is a better approach if you want your changes to still remain when you update the theme.