// === SEO + Performance Optimization (2026-10-01) ===
add_action('wp_head', function() {
    // Description 默认值（按页面类型覆盖）
    if (is_front_page()) {
        $desc = 'YRJC — China sourcing, purchasing, inspection, logistics & general trading. One accountable partner, one contract under Chinese law.';
    } elseif (is_page('contact')) {
        $desc = 'Request a free quote from YRJC. China sourcing, purchasing, inspection, factory visits. WhatsApp & email response within 24 hours.';
    } elseif (is_page('about')) {
        $desc = 'About YRJC — Zhuhai Hengqin Yiri Jingcheng Trading Co., Ltd. China-based sourcing partner for international B2B procurement.';
    } elseif (is_singular('page')) {
        $desc = wp_strip_all_tags(get_the_excerpt());
        $desc = $desc ? mb_substr($desc, 0, 155) : 'YRJC — China sourcing & trading partner.';
    } else {
        $desc = 'YRJC — Your trusted partner for China sourcing, purchasing, inspection, logistics & general trading.';
    }
    $desc = esc_attr($desc);
    $title = wp_get_document_title();
    $url = esc_url(home_url(add_query_arg([], $GLOBALS['wp']->request)));
    $img = esc_url(home_url('/wp-content/uploads/2026/09/yrjc-logo.svg'));

    // Meta description
    echo '<meta name="description" content="' . $desc . '" />' . "\n";

    // Open Graph
    echo '<meta property="og:type" content="' . (is_front_page() ? 'website' : 'article') . '" />' . "\n";
    echo '<meta property="og:title" content="' . esc_attr($title) . '" />' . "\n";
    echo '<meta property="og:description" content="' . $desc . '" />' . "\n";
    echo '<meta property="og:url" content="' . $url . '" />' . "\n";
    echo '<meta property="og:site_name" content="YRJC" />' . "\n";
    echo '<meta property="og:image" content="' . $img . '" />' . "\n";
    echo '<meta property="og:locale" content="en_US" />' . "\n";

    // Twitter Card
    echo '<meta name="twitter:card" content="summary_large_image" />' . "\n";
    echo '<meta name="twitter:title" content="' . esc_attr($title) . '" />' . "\n";
    echo '<meta name="twitter:description" content="' . $desc . '" />' . "\n";
    echo '<meta name="twitter:image" content="' . $img . '" />' . "\n";

    // Robots
    echo '<meta name="robots" content="index, follow, max-image-preview:large" />' . "\n";

    // Favicon + Apple touch icon
    echo '<link rel="icon" type="image/svg+xml" href="/wp-content/uploads/2026/09/yrjc-logo.svg" />' . "\n";
    echo '<link rel="alternate icon" type="image/png" href="/wp-content/uploads/2026/09/favicon.png" />' . "\n";
    echo '<link rel="apple-touch-icon" sizes="180x180" href="/wp-content/uploads/2026/09/apple-touch-icon.png" />' . "\n";

    // Preconnect / DNS prefetch
    echo '<link rel="preconnect" href="https://formspree.io" crossorigin />' . "\n";
    echo '<link rel="dns-prefetch" href="https://formspree.io" />' . "\n";
    if (is_front_page()) {
        echo '<link rel="preconnect" href="https://fonts.googleapis.com" crossorigin />' . "\n";
        echo '<link rel="dns-prefetch" href="https://fonts.googleapis.com" />' . "\n";
    }

    // Sitemap link
    echo '<link rel="sitemap" type="application/xml" title="Sitemap" href="/sitemap.xml" />' . "\n";

    // Theme color (mobile browser address bar)
    echo '<meta name="theme-color" content="#0066ff" />' . "\n";
    echo '<meta name="msapplication-TileColor" content="#0066ff" />' . "\n";

    // Organization Schema.org (homepage only)
    if (is_front_page()) {
        echo '<script type="application/ld+json">' . "\n";
        echo json_encode([
            '@context' => 'https://schema.org',
            '@type' => 'Organization',
            'name' => 'YRJC',
            'legalName' => 'Zhuhai Hengqin Yiri Jingcheng Trading Co., Ltd.',
            'url' => home_url('/'),
            'logo' => $img,
            'description' => 'China-based sourcing, purchasing, inspection, logistics and general trading partner for international B2B procurement.',
            'address' => [
                '@type' => 'PostalAddress',
                'streetAddress' => 'Room 8170, 8F, Cultural Studio, No. 66 Yiwen Yi Dao, Hengqin New District',
                'addressLocality' => 'Zhuhai',
                'addressCountry' => 'CN',
            ],
            'contactPoint' => [
                '@type' => 'ContactPoint',
                'telephone' => '+86-138-2412-9658',
                'contactType' => 'sales',
                'email' => 'sales@riyijingcheng.com',
                'availableLanguage' => ['English', 'Chinese'],
            ],
            'sameAs' => [],
        ], JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) . "\n";
        echo '</script>' . "\n";
    }
});

// Auto-add loading="lazy" to images that don't have it (except first image)
add_filter('the_content', function($content) {
    if (is_admin() || empty($content)) return $content;
    // Add loading=lazy to all img tags except first
    $count = 0;
    $content = preg_replace_callback(
        '/<img\s+([^>]*?)>/i',
        function($m) use (&$count) {
            $attrs = $m[1];
            // Skip if already has loading attribute
            if (preg_match('/\bloading\s*=/i', $attrs)) return $m[0];
            // Skip first image (above the fold)
            $count++;
            if ($count <= 2) return $m[0];
            // Add loading=lazy and decoding=async
            return '<img loading="lazy" decoding="async" ' . $attrs . '>';
        },
        $content
    );
    return $content;
}, 99);

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	<title>
	Comments on: Hello world!	</title>
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		<pubDate>Mon, 28 Sep 2026 14:33:09 +0000</pubDate>
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					<description><![CDATA[Hi, this is a comment.
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			<content:encoded><![CDATA[<p>Hi, this is a comment.<br />
To get started with moderating, editing, and deleting comments, please visit the Comments screen in the dashboard.<br />
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