column-width

column-width: auto;

column-width: 6rem;

column-width: 120px;

column-width: 18ch;

<section id="default-example">
  <p id="example-element">
    London. Michaelmas term lately over, and the Lord Chancellor sitting in
    Lincoln's Inn Hall. Implacable November weather. As much mud in the streets
    as if the waters had but newly retired from the face of the earth, and it
    would not be wonderful to meet a Megalosaurus, forty feet long or so,
    waddling like an elephantine lizard up Holborn Hill.
  </p>
</section>

#example-element {
  width: 100%;
  columns: auto;
  text-align: left;
}

/* 关键字值 */
column-width: auto;

/* <length> 值 */
column-width: 60px;
column-width: 15.5em;
column-width: 3.3vw;

/* 全局值 */
column-width: inherit;
column-width: initial;
column-width: revert;
column-width: revert-layer;
column-width: unset;

<p class="content-box">
  Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy
  nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. Ut wisi
  enim ad minim veniam, quis nostrud exercitation ullamcorper suscipit lobortis
  nisl ut aliquip ex ea commodo consequat.
</p>

.content-box {
  column-width: 100px;
}