<!DOCTYPE html>
<style>
div {
  -moz-column-count: 3;
  -moz-column-gap: 8px;
  -moz-column-rule: thick solid red;
  visibility: hidden;
  width: 300px;
  background-color: #fcc;
}
span {
  visibility: visible;
}
</style>
<div>
  <span>This is some content that is still shown within the columns.</span>
</div>