Style.css not working - by kristofferj - on WordPress WooCommerce support

I would prefer not to give out my login details, cause I just develop the site. It’s not mine.
So could you just give me the code to add in functions.php and to style.css(for styling of the custom css box)?
My current functions.php looks like this

<?php add_action( ‘wp_enqueue_scripts’, ‘theme_enqueue_styles’ );
function theme_enqueue_styles() {
wp_enqueue_style( ‘child-style’, get_stylesheet_uri(), array( ‘bootstrap’, ‘parent-style’ ) );
}

/* replace add to cart with view product */
function remove_loop_button(){
remove_action( ‘woocommerce_after_shop_loop_item’, ‘woocommerce_template_loop_add_to_cart’, 10 );
}
add_action(‘init’,’remove_loop_button’);

add_action(‘woocommerce_after_shop_loop_item’,’replace_add_to_cart’);
function replace_add_to_cart() {
global $product;
$link = $product->get_permalink();
echo do_shortcode(‘View Product‘);
}

Ok.
I want to change the font size in “Theme Options>Custom CSS” to a smaller size.

I don’t want to change p font-size site-wide. Just for the “Custom CSS” input box.