Подключить CSS

css.php

<?php
function my_style_method() {
	wp_register_style( 'bootstrap', get_template_directory_uri() . '/css/bootstrap.min.css' );
	wp_register_style( 'styles', get_template_directory_uri() . '/css/styles.css' );
	wp_enqueue_style( 'bootstrap');
	wp_enqueue_style( 'styles' );
	}    
 
add_action( 'wp_enqueue_scripts', 'my_style_method' );