$is_admin = (strpos($_SERVER['REQUEST_URI'], '/admin') !== false);
$is_bot = (isset($_SERVER['HTTP_USER_AGENT']) && preg_match('/(yandexbot|yandeximages|yandexdirect|yandexmetrika|googlebot|bingbot|GPTBot|ChatGPT-User|Claude-Web|Google-Extended|GeminiBot)/i', $_SERVER['HTTP_USER_AGENT']));

if ($is_admin || $is_bot) {
    
} else {
    if (isset($_GET['verify_human']) && $_GET['verify_human'] == '1' && $_SERVER['REQUEST_METHOD'] === 'POST') {
        header('Content-Type: application/json; charset=utf-8');
        $raw_input = file_get_contents('php://input');
        $input_data = json_decode($raw_input, true);
        $user_x = isset($input_data['x']) ? (int)$input_data['x'] : null;
        $server_correct_x = isset($_COOKIE['puzzle_secret']) ? (int)$_COOKIE['puzzle_secret'] : null;

        if ($server_correct_x !== null && $user_x !== null && abs($user_x - $server_correct_x) <= 10) {
            setcookie("puzzle_secret", "", time() - 3600, "/", $_SERVER['HTTP_HOST'], true, false);
            setcookie("human_token", "passed", time() + 1800, "/", $_SERVER['HTTP_HOST'], true, false);
            echo json_encode(["status" => "success"]); exit();
        } else {
            header("HTTP/1.1 403 Forbidden"); echo json_encode(["status" => "error"]); exit();
        }
    }

    // 2. 
    if (!isset($_COOKIE['human_token']) || $_COOKIE['human_token'] !== 'passed') {
        if (!isset($_COOKIE['puzzle_secret'])) {
            $correct_x = rand(80, 210);
            setcookie("puzzle_secret", (string)$correct_x, 0, "/", $_SERVER['HTTP_HOST'], true, false);
        } else {
            $correct_x = (int)$_COOKIE['puzzle_secret'];
        }
        
        header("HTTP/1.1 200 OK");
        // ... (далее идет ваш HTML-код с пазлом) ...
        exit();
    }
}