function sale_doujin_confirm_shortcode() {
    $api_id = 'vHDqAK3n5476RsF630wS'; // ← あなたのAPI ID
    $affiliate_id = 'hentair18-001';  // ← あなたの本番アフィリエイトID

    $api_url = "https://api.dmm.com/affiliate/v3/ItemList?api_id={$api_id}&affiliate_id={$affiliate_id}&operation=ItemList&version=2.00&service=doujin&floor=digital_doujin&hits=10&sort=date&output=json";

    $response = wp_remote_get($api_url);
    if (is_wp_error($response)) return 'API接続エラー: ' . $response->get_error_message();

    $body = wp_remote_retrieve_body($response);
    $data = json_decode($body, true);

    if (empty($data['result']['items'])) return '商品が取得できませんでした。';

    $html = '<div class="doujin-grid" style="display:flex; flex-wrap:wrap; gap:16px; justify-content:center;">';

    foreach ($data['result']['items'] as $item) {
        $title = esc_html($item['title']);
        $aff_url = esc_url($item['affiliateURL']);
        $img_url = esc_url($item['image']['large']);

        $html .= '<div style="width:160px; text-align:center; background:#fff; border:1px solid #ccc; border-radius:8px; overflow:hidden; box-shadow:0 1px 4px rgba(0,0,0,0.1);">';
        $html .= '<a href="' . $aff_url . '" target="_blank" rel="noopener">';
        $html .= '<img src="' . $img_url . '" alt="' . $title . '" style="width:100%; height:auto;">';
        $html .= '<div style="padding:6px 8px;">';
        $html .= '<p style="font-size:13px; font-weight:bold; height:3.5em; overflow:hidden;">' . $title . '</p>';
        $html .= '</div></a></div>';
    }

    $html .= '</div>';
    return $html;
}
add_shortcode('sale-doujin-confirm', 'sale_doujin_confirm_shortcode');