<?xml version="1.0" encoding="UTF-8"?>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" style="-webkit-writing-mode: vertical-rl;">
    <style>
        div {
            position: absolute;
            width: 100px;
            height: 100px;
            border: 3px solid black;
            left: 0;
            right: 0;
        }
    </style>
    <div></div>
</html>