foto-portfolio/admin/contact.php

<?php
/**
 * Contact page editor: heading, intro text and contact methods shown on the
 * public contact.php page.
 */
require dirname(__DIR__) . '/app/bootstrap.php';
auth_require();

$site = site_get();

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    csrf_verify();

    $site['contact_title']     = trim((string)($_POST['contact_title'] ?? ''));
    $site['contact_text']      = trim((string)($_POST['contact_text'] ?? ''));
    $site['contact_email']     = trim((string)($_POST['contact_email'] ?? ''));
    $site['contact_phone']     = trim((string)($_POST['contact_phone'] ?? ''));
    $site['contact_instagram'] = trim((string)($_POST['contact_instagram'] ?? ''));

    site_save($site);
    flash_set('Contact page saved.');
    redirect('contact.php');
}

admin_header('Contact', 'contact');
flash_render();
?>
<h1>Contact page</h1>
<form method="post" class="card">
    <?= csrf_field() ?>

    <label for="ct">Heading</label>
    <input type="text" id="ct" name="contact_title" value="<?= e($site['contact_title'] ?? '') ?>">

    <label for="cx">Intro text</label>
    <textarea id="cx" name="contact_text"><?= e($site['contact_text'] ?? '') ?></textarea>
    <p class="help">Shown below the heading. Line breaks are kept.</p>

    <label for="ce">Email</label>
    <input type="text" id="ce" name="contact_email" value="<?= e($site['contact_email'] ?? '') ?>" placeholder="hello@example.com">

    <label for="cp">Phone</label>
    <input type="text" id="cp" name="contact_phone" value="<?= e($site['contact_phone'] ?? '') ?>" placeholder="+49 30 1234567">

    <label for="ci">Instagram</label>
    <input type="text" id="ci" name="contact_instagram" value="<?= e($site['contact_instagram'] ?? '') ?>" placeholder="@handle or full URL">

    <p class="help">Leave a field empty to hide it on the contact page.</p>
    <button type="submit">Save</button>
    <a class="btn btn-ghost" href="../contact.php" target="_blank" rel="noopener" style="margin-left:.6rem">View page ↗</a>
</form>
<?php admin_footer(); ?>