<!DOCTYPE html>
<html>
      <head>
            <title>Resolving percent height inside multicol</title>
        </head>
      <body>
            <p>There should be a blue square below.</p>
            <div style="-webkit-columns:3; columns:3; -webkit-column-gap:0; column-gap:0; width:99px; height:99px;">
                  <div style="height:300%; background:blue;"></div>
              </div>
        </body>
  </html>