<div class="container">
    <div style="text-align: center;">
        <?php if (!empty($_SESSION['error'])): ?>
            <div style="background-color: red;padding: 5px;margin: 15px"><?= $_SESSION['error'] ?></div>
            <?php unset($_SESSION['error']) ?>
        <?php endif; ?>
    </div>

    <div style="text-align: center;">
        <?php if (!empty($_SESSION['message'])): ?>
            <div style="background-color: greenyellow;padding: 5px;margin: 15px"><?= $_SESSION['message'] ?></div>
            <?php unset($_SESSION['message']) ?>
        <?php endif; ?>
    </div>
</div>