PHP problem

Index.php:

    <?php
        $pageTitle = "Kyle Culp";
        echo "$css[0];
        include('php/header.php');
    ?>


header.php:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title><?php echo $pageTitle; ?></title>
    <meta name="description" content="An average website I guess." />
    <link href="css/styles.css" rel="stylesheet" type="text/css" />
    <link href="css/<?php $css=array("index.css","portfolio.css","projects.css","contact.css"); ?>" type="text/css" />
</head>
<body>