css/css-pseudo/first-line-input-textarea.tentative.html

<!DOCTYPE html>
<title>::first-line on input / textarea</title>
<link rel="match" href="input-textarea-ref.html">
<link rel="help" href="https://drafts.csswg.org/css-pseudo-4/#first-text-line">
<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/13926">
<style>
.direct::first-line {
  color: red;
}
.container::first-line {
  color: red;
}
.container > input {
  display: block;
}
</style>
<input class="direct" value="Some text">
<textarea class="direct">
  Some more text
</textarea>
<div class="container"><input value="Some more text"></div>