Content is not populated on parent elements

[Gigabyte5671]

Content - specifically from the content style property - is not populated on parent elements.

Reproduction

main {
    content: 'A';
}
main section {
    content: 'B';
}

The above CSS produces the following HTML:

<main><section>B</section></main>

Expected Result

The above CSS should produce something like this:

<main>A<section>B</section></main>

Or this:

<main><section>B</section>A</main>