chromium/third_party/blink/web_tests/fast/forms/color-scheme/datetimelocal/datetimelocal-appearance-basic.html

<!DOCTYPE html>
<meta name="color-scheme" content="light dark">
<script src="../../../../resources/run-after-layout-and-paint.js"></script>
<script src="../../resources/common.js"></script>
<body>

<!-- no style for reference -->
<ul>
  <li>Datetime-local: <input type="datetime-local" /></li>
</ul>

<!-- disabled, readonly -->
<ul>
  <li>Datetime-local disabled: <input type="datetime-local" disabled/></li>
  <li>Datetime-local readonly: <input type="datetime-local" readonly/></li>
</ul>

<!-- RTL -->
<ul>
  <li>Datetime-local RTL: <input type="datetime-local" value="2019-02-14T13:02" dir="rtl"/></li>
</ul>

<!-- font-size, font-weight -->
<ul>
  <li>Datetime-local font-size, font-weight: <input type="datetime-local" value="2019-02-14T13:02" style="font-size: 36px; font-weight: bold;"/> </li>
</ul>

<!-- hover -->
<ul>
  <li>Datetime-local hover: <input type="datetime-local" id="hoverTarget" value="2019-02-14T13:02"/></li>
</ul>

<!-- small width -->
<ul>
  <li>Datetime-local width: 10px: <input type="datetime-local" style="width: 10px;"/> </li>
</ul>

<!-- zoom -->
<ul>
  <li>Datetime-local zoom: 1.5: <input type="datetime-local" style="zoom: 1.5;"/></li>
  <li>Datetime-local zoom: 3: <input type="datetime-local" style="zoom: 3;"/></li>
</ul>

<script>

runAfterLayoutAndPaint(function() {
  var target = document.getElementById('hoverTarget');
  hoverOverElement(target);
}, true);

</script>

</body>