<!DOCTYPE html>
<script>
if (window.testRunner)
testRunner.setPrinting();
if (window.internals)
internals.settings.setShouldPrintBackgrounds(true);
</script>
<style>
html { writing-mode: vertical-rl; }
body { margin: 0; }
</style>
<div style="contain:size; position:absolute; left:0; width:100px; height:100px;">
<div style="margin-left:-100px; width:200px; height:100px; background:blue;"></div>
</div>
<p style="writing-mode:horizontal-tb; margin-left:1em; margin-top:150px;">
When printed, there should be two pages. There should be a blue square on
each page. On the first page, the square should be at the left-hand side of
the page, and on the second page, it should be at the right-hand side.
</p>
<div style="break-before:page; block-size:10px;"></div>