Show HN: Darken – Darkmode Made Easy(github.com)

  <button id="dm-toggle">Toggle darkmode</button>
  <script>
    const darkmode = new darken({
      toggle: "#dm-toggle",
      variables: {
        "--primary-color": ["#ffffff", "#000000"],
        "--secondary-color": ["#000000", "#ffffff"],
      }
    });
  </script>

  <script>
    // (Add the button to the document in JS,
    // since it’ll only work if this JS runs anyway.)
  </script>
  <style>
    body {
      --primary-color: #ffffff;
      --secondary-color: #000000;
    }
  </style>
  <style media="screen and (prefers-color-scheme: dark)">
    body {
      --primary-color: #000000;
      --secondary-color: #ffffff;
    }
  </style>