remove default <style></style> of head

// paste this into your theme functions.php

/*
remove default <style></style> of head
*/
function remove_admin_login_header() {
    remove_action('wp_head', '_admin_bar_bump_cb');
    remove_action('wp_footer', '_admin_bar_bump_cb');

	// this for <style type="text/css" media="print">#wpadminbar { display:none; }</style>
	if (! is_user_logged_in() )
	add_filter( 'show_admin_bar', '__return_false' );

}
add_action('get_header', 'remove_admin_login_header');