Arc-hive-omeka-theme/view/omeka/site/media/show.phtml

<?php
$translate = $this->plugin('translate');
?>
<?php $this->htmlElement('body')->appendAttribute('class', 'media resource show'); ?>

<!-- arc-hive insert begins -->
<?php
//$site->pages();
// set header image
$img_src = $this->getHelperPluginManager()->get('archiveSiteMeta')->getSiteImage($site);
if (!$img_src) {
  $img_src = '/themes/archive/asset/img/default-header-image.jpg';
}
?>
<style>
#archive_header_img {
   background:url("<?= $img_src ?>") no-repeat;
   width:100%;
   height:100px;
}
</style>

<script>
<?php
  if ($this->site->title() != "Collections") {
    $_html = '<a href="'.$this->site->url().'">'.$this->site->title().'</a>';
  } else {
    $_html = $this->site->title();
  }
?>
$("#archive_page_title").html('<?php echo $_html ?>');
</script>
<!-- arc-hive insert ends -->


<div class="resource-title">
<?php echo $this->pageTitle($media->displayTitle(), 2); ?>
</div>
<?php $this->trigger('view.show.before'); ?>
<?php echo $media->render(); ?>
<?php echo $media->displayValues(); ?>

<button onclick="window.history.back()">
<h3 class="label">Back</h3>
</button>

<?php $this->trigger('view.show.after'); ?>