header.php

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.3/dist/css/bootstrap.min.css">
    <link rel="stylesheet" href="style.css">
    <title>Première Appli PHP</title>
</head>

<body>
    <header>
        <nav>
            <ul class="nav justify-content-center">
                <li class="nav-item">
                    <a class="nav-link" aria-current="page" href="index.php">Accueil</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" href="recap.php">Recapitulatif</a>
                </li>
            </ul>
        </nav>
    </header>

</body>

</html>