chromium/third_party/blink/web_tests/wpt_internal/css/css-fonts/variable-opsz-zoom-size-adjust-ref.html

<!DOCTYPE html>
<html class="reftest-wait">
<meta charset="utf-8">
<style>
    @font-face {
    font-family: variabletest_box;
    src: url(resources/variabletest_box.ttf);
    }

    body {
    font-family: variabletest_box, sans-serif;
    font-optical-sizing: none;
    }

    .columns {
    display: flex;
    gap: 20px;
    }
</style>
<div class="columns">
<div>
<div style="font-size:   9px; font-variation-settings: 'opsz'    9;">B</div>
<div style="font-size:  18px; font-variation-settings: 'opsz'   18;">B</div>
<div style="font-size:  36px; font-variation-settings: 'opsz'   36;">B</div>
</div>
<div>
<div style="font-size:  72px; font-variation-settings: 'opsz'   72;">B</div>
<div style="font-size:  96px; font-variation-settings: 'opsz'   96;">B</div>
</div>
<div>
<div style="font-size:  36px; font-variation-settings: 'opsz'  128;">B</div>
<div style="font-size:  72px; font-variation-settings: 'opsz'   12;">B</div>
</div>
</div>
<script>
  matchMedia('(resolution: 2dppx)').addEventListener("change", zoomReached, { once: true })
    if (window.testRunner)
        testRunner.setPageZoomFactor(2);

  function zoomReached() {
      document.fonts.ready.then(
          () => { document.documentElement.classList.remove("reftest-wait"); });
  }
</script>
</html>