trisquel-icecat/icecat/layout/reftests/forms/input/checkbox/checkbox-clamp-01-ref.html

<style>
  div {
    top: 50px;
    line-height: 0px;
    position: relative;
  }
</style>

<div>
  <input type="checkbox">
  <input type="checkbox" checked>
</div>