actuel-inactuel/site/snippets/cover.php

<?php
$isOpen = isset($isOpen) ? $isOpen : false;
?>

<header 
  x-data="{
    activeTab: ''
  }"
  :class="activeTab.length > 0 ? 'open' : 'close'"
  class="page-cover"
>
  <div class="title-wrapper">
    <?= $slots->title() ?>
  </div>
  <?= $slots->tabs() ?>
</header>