This is simple code used in css.

div {
background: url(background.jpg);
background-size: 800px 600px;
background-repeat: no-repeat;
}

If you not want to use background image, remove 1st line of code. You can use background size in "%" also, thats will fits in all browser.

This is how you can hide download url in PHP:

<?php
$fakeFileName= "fakeFileName.zip";
$realFileName = "realFileName.zip";

$file = "downloadFolder/".$realFileName;
$fp = fopen($file, 'rb');

header("Content-Type: application/octet-stream");
header("Content-Disposition: attachment; filename=$fakeFileName");
header("Content-Length: " . filesize($file));
fpassthru($fp);
?>

You can see all steps to hide download url here http://5ss.co/viewtopic.php?f=26&p=3[^]