[CSS21] can't account for vertical space between inline box and its block-level container (Roger Baker)

Some text

Code is:

  p
  {
  border: blue solid 1px;
  font-family: serif;
  font-size: 100px;
  line-height: 1;
  margin: 99px auto 0px 1px;
  }

  span {border: orange solid 1px;}
  
  <p><span>Some text</span></p>