m has an orthogonal baseline, use the synthesized
baseline (bottom of the border box of the first item). -->
<div>
should align with the middle
<div class="inline-grid column" style="width: 40px; height: 40px;">
    <div style="writing-mode: vertical-rl; width: 40px; height: 20px; border-bottom: 1px solid black"></div>
    <div style="writing-mode: vertical-rl; width: 40px; height: 19px"></div>
</div>
of the grey box
</div>

<!-- More tests on the right side of the page. -->
<div style="position: absolute; 