child theme

Can you post a link to your site with the child theme active?

Looks like a minor issue with the theme. The actual stylesheet doesn’t get loaded correctly if you’re using a child theme because the author uses get_stylesheet_directory_uri() instead of get_template_directory_uri() in functions.php.

For now, you could work around this issue by making a child theme manually. You need two files:

style.css:

/*
Theme Name: Hellish Simplicity Child
Template: hellish-simplicity
*/

/* Changes below this line
--------------------------*/

And functions.php:

<?php
add_action( 'wp_enqueue_scripts', 'theme_enqueue_styles', 20 );
function theme_enqueue_styles() {
    wp_dequeue_style( 'style' );
    wp_enqueue_style( 'parent-style', get_template_directory_uri() . '/style-compiled.css' );
    wp_enqueue_style( 'child-style', get_stylesheet_uri(), array( 'parent-style' ) );
}

You should place these two files in your child theme’s folder, replacing any files of the same name that are already there.