<!DOCTYPE html>
<html>
<head>
<title>Reference: ::first-line supports opacity.</title>
<link rel="author" title="Mats Palmgren" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1639664">
<link rel="mismatch" href="first-line-opacity-001-not-ref.html">
  <style>
    fl {
      opacity: 0;
    }
  </style>
</head>
<body>
  <p><fl>First</fl><br>Second</p>
</body>
</html>