id';
  assert_equals(getComputedStyle(box).borderInlineStartWidth, '10px');
  assert_equals(getComputedStyle(box).borderInlineEndWidth, '10px');
  assert_equals(getComputedStyle(box).borderInlineWidth, '10px');

  box.style.borderInlineStartStyle = 'hidden';
  box.style.borderInlineEndStyle = 'dashed';
  assert_equals(getComputedStyle(box).borderInlineStartWidth, '0px');
  assert_equals(getComputedStyle(box).borderInlineEndWidth, '10px');
  assert_equals(getComputedStyle(box).borderInlineWidth, '0px 10px');