css/css-pseudo/placeholder-input-number.html

<!doctype html>
<title>CSS Test: ::placeholder applies to input type="number"</title>
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
<link rel="mismatch" href="placeholder-input-number-notref.html">
<link rel="help" href="https://drafts.csswg.org/css-pseudo-4/#placeholder-pseudo">
<style>
#number::placeholder {
  color: green;
}
</style>
<input id="number" type="number" placeholder="Placeholder">