How do the default themes reference style.css?

The stylesheet is registered and enqueued by a function called twentyfourteen_scripts() in the theme’s functions.php.
Callbacks hooked into the style loader/dependency system will be echoed on the wp_head action in the wp_head() function.

Which, by the way, is how you should be loading your own stylesheets. There is a similar system for scripts.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)