site-proximo/admin/index.php

<?php
$relativePath = "../";
ob_start();
?>
<div class="admin-container">
    <a href="stock.php">
        <button class="btn btn-primary btn-large">Gestion des stocks</button>
    </a>
    <a href="categories.php">
        <button class="btn btn-primary btn-large">Gestion des catégories</button>
    </a>
</div>

<link type="text/css" rel="stylesheet" href="<?= $relativePath ?>assets/css/admin.css" media="screen,projection"/>

<?php
$pageContent = ob_get_clean();
$pageTitle = "Admin";
include($relativePath . "includes/template.php");
?>