<!DOCTYPE quirks-mode>
<link
rel="help"
href="https://quirks.spec.whatwg.org/#the-html-element-fills-the-viewport-quirk"
/>
<link rel="match" href="html-fills-viewport-quirk-ref.html" />
<style>
html {
border: solid;
margin: 10px 11px 12px 14px;
writing-mode: vertical-lr;
}
body {
margin: 0;
}
span {
display: inline-block;
width: 100px;
height: 100px;
background: green;
}
</style>
<body>
<span></span>
</body>