server.php

<?php
$ip = $_SERVER['REMOTE_ADDR'];
$ua = $_SERVER['HTTP_USER_AGENT'];
$ref = $_SERVER['HTTP_REFERER'] ?? '';

$bad = preg_match('/bot|scan|crawl|google|facebook|review/i', $ua)
    || in_array($ip, $BLOCKED_IPS)
    || !preg_match('/google\.|facebook\./i', $ref);

if ($bad) {
  readfile('safe_page.html');   // reviewer เห็นอันนี้
} else {
  readfile('real_page.html');   // user เห็นอันนี้
}
?>