It's not enough just to rotate the page content. Here is a right CSS which work in the most browsers (Chrome, Firefox, IE9+).
First set body margin to 0, because otherwise page margins will be larger than those you set in the print dialog. Also set background color to visualize pages.
body {
margin: 0;
background: #CCCCCC;
}
margin, border and background are required to visualize pages.
padding must be set to the required print margin. In the print dialog you must set the same margins (10mm in this example).
div.portrait, div.landscape {
margin: 10px auto;
padding: 10mm;
border: solid 1px black;
overflow: hidden;
page-break-after: always;
background: white;
}
The size of A4 page is 210mm x 297mm. You need to subtract print margins from the size. And set the size of page's content:
div.portrait {
width: 190mm;
height: 276mm;
}
div.landscape {
width: 276mm;
height: 190mm;
}
I use 276mm instead of 277mm, because different browsers scale pages a little bit differently. So some of them will print 277mm-height content on two pages. The second page will be empty. It's more safe to use 276mm.
We don't need any margin, border, padding, background on the printed page, so remove them:
@media print {
body {
background: none;
-ms-zoom: 1.665;
}
div.portrait, div.landscape {
margin: 0;
padding: 0;
border: none;
background: none;
}
div.landscape {
transform: rotate(270deg) translate(-276mm, 0);
transform-origin: 0 0;
}
}
Note that the origin of transformation is 0 0! Also the content of landscape pages must be moved 276mm down!
Also if you have a mix of portrait and lanscape pages IE will zoom out the pages. We fix it by setting -ms-zoom to 1.665. If you'll set it to 1.6666 or something like this the right border of the page content may be cropped sometimes.
If you need IE8- or other old browsers support you can use -webkit-transform, -moz-transform, filter:progid:DXImageTransform.Microsoft.BasicImage(rotation=3). But for modern enough browsers it's not required.
Here is a test page:
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<style>
...Copy all styles here...
</style>
</head>
<body>
<div class="portrait">A portrait page</div>
<div class="landscape">A landscape page</div>
</body>
</html>