Bootstrap to WP site loads white

I'm working through the steps and I think my funcitons.php file is causing the site not to load but I can't see where. Help?

functions.php

<?php

// Load theme CSS function theme_styles() {

wp_enqueue_style('bootstrap_css', get_template_directory_uri() . '/css/bootstrap.min.css');
wp_enqueue_style('main_css', get_template_directory_uri() . '/style.css');

} add_action('wp_enqueue_scripts', 'theme_styles'); // Load theme JS function theme_js() {

global $wp_scripts; 

wp_register_script( 'html5_shiv', 'https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js', '', '', false ); wp_register_script( 'respond_js', 'https://oss.maxcdn.com/respond/1.4.2/respond.min.js', '', '', false );

$wp_scripts->add_data( 'html5_shiv', 'conditional', 'lt IE 9' ); $wp_scripts->add_data( 'respond_js', 'conditional', 'lt IE 9' );

$wp_enqueue_script( 'bootstrap_js', get_template_directory_uri() . '/js/bootstrap.min.js', array('jquery'), '', true );

} add_action('wp_enqueue_scripts', 'theme_js');

//Enable Custom Menus add_theme_support ('menus');

function register_theme_menus() {

register_nav_menus (
    array(
    'header-menu' => __( 'Header Menu' )
        )
    );

} add_action('init', 'register_theme_menus'); ?>