Relevant spec sections:

https://drafts.csswg.org/selectors-4/#the-dir-pseudo
https://html.spec.whatwg.org/multipage/semantics-other.html#selector-ltr

The interesting cases to test are from the definition of "directionality" in HTML:
https://html.spec.whatwg.org/multipage/dom.html#the-directionality

• element with dir="ltr" matches :dir(ltr)
• root element without dir attr

What about trying running it on the side together with Tracium so we can see how it works.

Sometimes when you translate some word, you may want to hear its pronunciation to learn the word better.

We may add some buttons somewhere into the translation panel for pronunciations.

When you click the audio icon it pronounces the selected text.