Unlock Hidden Power: 6 Little-Known Ways to Master Custom Block Styles in WordPress
//add style.css to editor
function add_theme_editor_styles() {
add_editor_style( 'style.css' );
}
add_action( 'after_setup_theme', 'add_theme_editor_styles' );
Optional: removing unwanted core block styles
Now that you know how to add block styles to your theme or your plugin, you might also want to remove some additional block styles that come with the block editor out of the box.
There are two functions you’ll need to address:
Block styles can only be unregistered in the same coding language used to register them. All core blocks are registered with JavaScript.
