n if div#multi-col's 'height' is set to '49px'.">

  <style>
  div#multi-col
    {
      background-color: yellow; /* Not part of the test */
      columns: 2 auto;
      column-fill: balance; /* Balance content equally between columns, if possible. */
      height: 250px; /* more than enough to display "TEXT" */
    }

  div#unbreakable-block
    {
      background-color: lime; /* Not part of the test */
      font-size: 50px;
      line-height: 1.2; /* Not part of the test */
      writing-mode: vertical-