chromium/third_party/blink/web_tests/wpt_internal/printing/page-fitting-005-print.html

<!DOCTYPE html>
<link rel="match" href="page-fitting-005-print-ref.html">
<meta name="assert" content="When the page is scaled down to fit, the area available to margin boxes shrinks too.">
<script>
  if (window.testRunner) {
    testRunner.setPrintingSize(400, 300);
    testRunner.setShouldCenterAndShrinkToFitPaper(true);
  }
</script>
<style>
  @page {
    size: 800px 600px;
    margin: 100px;
    border: 10px solid;

    @top-left-corner {
      box-sizing: border-box;
      border: 5px solid lime;
      width: 50px;
      height: 100%;
      content: "";
      background: green;
    }
    @top-right-corner {
      box-sizing: border-box;
      border: 5px solid lime;
      width: 100%;
      height: 50px;
      content: "";
      background: green;
    }
    @bottom-right-corner {
      box-sizing: border-box;
      border: 5px solid lime;
      width: 50px;
      height: 100%;
      content: "";
      background: green;
    }
    @bottom-left-corner {
      box-sizing: border-box;
      border: 5px solid lime;
      width: 100%;
      height: 50px;
      content: "";
      background: green;
    }
  }
</style>