query("SELECT setting_value FROM settings WHERE setting_key = 'site_logo'"); $site_logo = $stmt->fetchColumn() ?: 'assets/pasted-20260207-134833-7329dc42.jpg'; $error = ''; if ($_SERVER['REQUEST_METHOD'] === 'POST') { $username = $_POST['username'] ?? ''; $password = $_POST['password'] ?? ''; if ($username === 'admin') { $stmt = $pdo->prepare("SELECT password FROM users WHERE username = 'admin'"); $stmt->execute(); $user = $stmt->fetch(); if ($user && password_verify($password, $user['password'])) { $_SESSION['admin_logged_in'] = true; header('Location: admin.php'); exit; } else { $error = '用户名或密码错误'; } } else { $error = '权限不足'; } } ?>