<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Minimum height on fieldset</title>
    <style>
    div {
      writing-mode: vertical-lr;
    }
    fieldset {
      background:rgba(0,0,0,0.1);
      border-color:teal;
      border-width:2px;
      height:200px;
    }
    </style>
  </head>
  <body>
    <div>
      <fieldset>
	<p>Lorem ipsum.</p>
      </fieldset>
    </div>
  </body>
</html>