wordpress add CSS code only to a user code example

Example: add user role to wp admin page css

function wpa66834_role_admin_body_class( $classes ) {
    global $current_user;
    foreach( $current_user->roles as $role )
        $classes .= ' role-' . $role;
    return trim( $classes );
}
add_filter( 'admin_body_class', 'wpa66834_role_admin_body_class' );