<!doctype html>
<meta charset="utf-8">
<title>CSS Test Reference</title>
<style>
.dark {
  color-scheme: dark;
  background-color: Canvas;
  color: CanvasText;
  border: 2px solid purple;
}
.light {
  background-color: white;
  color: black;
  border: 2px solid blue;
}
</style>
<div class="light">
  Always light
</div>
<div class="dark">
  Always dark
</div>
