Load style.css after bootstrap

Hi and thank you for this so clean and powerfull theme!

I want to know the best way for override bootstrap style.css
I’ve looked for on functions.php but I’m not sure if something is wrong because in addition to I’m a newbie, it seems that style.css is loaded after bootstrap as you comment here:

//load theme style file after bootstrap style
    wp_enqueue_style('boot_Strap-style', get_stylesheet_uri());

I dont understand why all my styles are overrided by bootstraps.
I could put !important after each class but I think is not the best way.

Thank you very much in advanced.