Custom styles for the Event Espresso 4 events calendar's iframe. Add the calendar-iframe-custom-styles.css file to your child theme (top level).

calendar-iframe-custom-styles.css

#ee-category-legend-ul #ee-category-li-70,
#ee-category-submit option[value=unlisted] {
    display:none
}

functions.php

<?php
//* Please do NOT include the opening php tag, except of course if you're starting with a blank file

add_filter('FHEE__CalendarIframe__display__css', 'tw_ee_add_iframe_calendar_custom_styles', 11, 2);

function tw_ee_add_iframe_calendar_custom_styles(array $stylesheets, $object) {
    $stylesheets['calendar_iframe_custom'] = get_stylesheet_directory_uri() . DS . 'calendar-iframe-custom-styles.css';
    return $stylesheets;
}