Styles missing on a mapped domain

The Domain Mapping doesn't show theme's styles. The styles return 404 error.
The wp-content folder is renamed from the wp-config.php file:

define( 'WP_CONTENT_DIR', dirname(__FILE__) . '/blog/wp-content' );
define( 'WP_CONTENT_URL', 'http://example/blog/wp-content' );

And the theme's styles loading from:

mapped.com/themes/theme-name/style.css

Instead of:

mapped.com/wp-content/themes/theme-name/style.css