querySelector('rt').getBoundingClientRect();
  document.querySelector('span').style.left = '100px';
  const rubyAfter = document.querySelector('ruby').getBoundingClientRect();
  const rtAfter = document.querySelector('rt').getBoundingClientRect();
  assert_equals(rubyBefore.x + 100, rubyAfter.x);
  assert_equals(rtBefore.x + 100, rtAfter.x);
}, 'position:relative on a ruby parent should move the ruby and the annotation');

test(() => {
  container.innerHTML = `b<ruby style="position:relative">base
      <rt