I created a child theme and created a functions.php file in the child theme directory that also has the required style.css file and a seperate custom CSS file that I want to load. This is the code I use:
<? php
add_action('wp_head', 'add_landing_css');
function add_landing_css() {
wp_enqueue_style('landing_css', get_stylesheet_directory_uri().'/landing.css','screen');
}
?>
When I add this code to functions.php every page on my website is blank. It doesn't load anything. When I delete functions.php file my website works as normal. I use a theme called Modest from elegant themes.