Stylesheet does not load despite functions.php

• You can used to below snippet code for enqueue your css

<?php
function myBlog_files() {
wp_enqueue_style('styles', get_template_directory_uri()./style.css);
}
add_action('wp_enqueue_scripts', 'myBlog_files');
?>

• Add Your custom-style.css in another folder you add in folder name in before custom-style.css

For Example :

wp_enqueue_style('styles', get_template_directory_uri()./folder name/style.css);

Refer link for more knowledge