add_action( 'wp_head', function () {
    if ( ! is_front_page() ) return;
    $up = 'https://woodduckpools.com/wp-content/uploads/2026/10/';
    echo '<link rel="preload" as="image" fetchpriority="high" media="(max-width: 767px)" href="' . $up . 'slide01_3-1_mobile.webp">' . "\n";
    echo '<link rel="preload" as="image" fetchpriority="high" media="(min-width: 768px)" href="' . $up . 'slide01_3-1_desktop.webp">' . "\n";
}, 1 );