details-pseudo-elements-001-ref.html

<!DOCTYPE HTML>
<title>Details pseudo-elements</title>
<!-- This test is (at time of writing) _EXTREMELY_ tentative. -->
<style>

div { background: aqua }

</style>

<details open>
  <summary>The summary</summary>
  <div>The details!</div>
</details>

chromium/third_party/blink/web_tests/external/wpt/html/rendering/the-details-element/details-pseudo-elements-001-ref.html