</head>
<?php
/* Get the Page Slug to Use as a Body Class, this will only return a value on pages! */
$class = '';
/* is it a page */
if( is_page() ) {
global $post;
/* Get an array of Ancestors and Parents if they exist */
$parents = get_post_ancestors( $post->ID );
/* Get the top Level page->ID count base 1, array base 0 so -1 */
$id = ($parents) ? $parents[count($parents)-1]: $post->ID;
/* Get the parent and set the $class with the page slug (post_name) */
$parent = get_post( $id );
$class = $parent->post_name;
}
?>
<body <?php body_class( $class ); ?>>
<?php
global $post;
$parents = get_post_ancestors( $post->ID );
/* Get the ID of the 'top most' Page if not return current page ID */
$id = ($parents) ? $parents[count($parents)-1]: $post->ID;
if(has_post_thumbnail( $id )) {
get_the_post_thumbnail( $id, 'thumbnail');
}
?>