css/css-values/viewport-units-keyframes.html

<!DOCTYPE html>
<title>Viewport units in @keyframes</title>
<link rel="help" href="https://drafts.csswg.org/css-values-4/#viewport-relative-lengths">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<style>
  iframe {
    width: 200px;
    height: 100px;
  }
</style>

<iframe id=iframe></iframe>

<script>

const doc = iframe.contentDocument;
const win = iframe.contentWindow;

function test_interpolated_value(from, to, expected) {
  test((t) => {
    t.add_cleanup(() => { doc.body.innerHTML = ''; });
    doc.body.innerHTML = `
      <style>
        @keyframes anim {
          from { height: ${from}; }
          to { height: ${to}}
        }
        div { animation: anim linear 10s -5s paused; }
      </style>
      <div></div>
    `;
    let div = doc.querySelector('div');
    assert_equals(win.getComputedStyle(div).height, expected);
  }, `Interpolation from ${from} to ${to} is ${expected} at 50%`);
}

test_interpolated_value('0px', '100vw', '100px');
test_interpolated_value('0px', '100vi', '100px');
test_interpolated_value('0px', '100vmax', '100px');
test_interpolated_value('0px', '100svw', '100px');
test_interpolated_value('0px', '100svi', '100px');
test_interpolated_value('0px', '100svmax', '100px');
test_interpolated_value('0px', '100lvw', '100px');
test_interpolated_value('0px', '100lvi', '100px');
test_interpolated_value('0px', '100lvmax', '100px');
test_interpolated_value('0px', '100dvw', '100px');
test_interpolated_value('0px', '100dvi', '100px');
test_interpolated_value('0px', '100dvmax', '100px');

test_interpolated_value('0px', '100vh', '50px');
test_interpolated_value('0px', '100vb', '50px');
test_interpolated_value('0px', '100vmin', '50px');
test_interpolated_value('0px', '100svh', '50px');
test_interpolated_value('0px', '100svb', '50px');
test_interpolated_value('0px', '100svmin', '50px');
test_interpolated_value('0px', '100lvh', '50px');
test_interpolated_value('0px', '100lvb', '50px');
test_interpolated_value('0px', '100lvmin', '50px');
test_interpolated_value('0px', '100dvh', '50px');
test_interpolated_value('0px', '100dvb', '50px');
test_interpolated_value('0px', '100dvmin', '50px');

</script>