I spoke too soon, it doesn't work. But I really don't understand why not. The code Calibre puts in the titlepage.xhtml is:
Code:
<?xml version='1.0' encoding='utf-8'?>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<meta name="calibre:cover" content="true"/>
<title>Cover</title>
<style type="text/css" title="override_css">
@page {padding: 0pt; margin:0pt}
body { text-align: center; padding:0pt; margin: 0pt; }
</style>
</head>
<body>
<div>
<svg xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="100%"
height="100%" viewBox="0 0 600 800" preserveAspectRatio="none">
<image width="600" height="800" xlink:href="cover1.jpeg"/>
</svg>
</div>
</body>
</html>
That still makes left and right margins when viewing the cover in the Kobo.
If I completely remove the size tags from that code, the cover is even worse: left margin smaller than right margin, and top and bottom margins too!
The following code does work, but I have to put that in manually. I really can't see anything in the above code that would mess the cover up...
Code:
<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<style type="text/css">
/*<![CDATA[*/
body.sgc-1 {margin: 0px; text-align: center;}
/*]]>*/
</style>
</head>
<body class="sgc-1">
<div><img alt="" src="cover1.jpeg" /></div>
</body>
</html>