nded version are all 1em.
</ul>

<section>
<h4>A double stripe</h4>
<p>Used for the <i>hwid</i> feature.
<figure>
<img src="img/stripe_double.svg" width="300">
<figcaption>double stripe. reference glyph on left, hwid glyph on right.</figure>
</figure>
</section>

<section>
<h4>A triple stripe</h4>
<p>Used for the <i>twid</i> feature.
<figure>
<img src="img/stripe_triple.svg" width="300">
<figcaption>triple stripe. reference glyph on left, twid glyph on right.</figure>
</figure>
</section>

<section>
<h4>A q