[Bug] Responsive preview to shrink its height regarding to scaled inner iframe

[softmarshmallow]

  /* FIXME: this should be a height
  // this should work, but the flex is making inner iframe height to shrink.
  height: max(${(props) => props.heightscale * 100}%, 100%);
    ref:
    - https://stackoverflow.com/questions/51288769/scaling-a-flexbox-child-with-transform-leaves-empty-space
    - https://www.reddit.com/r/css/comments/q5cvei/css_fitcontent_on_parent_wont_work_for_scaled_item/
  */

The height calculation logic is decent, but it seems to be broken due to flex use.
height: max(${(props) => props.heightscale * 100}%, 100%);

This is a known issue, will be included in the production release. It will be fixed in short time.