<!DOCTYPE html>
<html>
<head>
  <link href="test1.css" rel="stylesheet">
  <link href="test2.css" rel="stylesheet">
  <link href="test3.css" rel="stylesheet">
</head>
<body>
  <div class="a1 b1">.b1 has the correct mapping line 11</div>
  <div class="a2 b2">.b2 expected line 11 but received 12</div>
  <div class="a3 b3">.b3 expected line 11 but received 7</div>
</body>
</html>