<!DOCTYPE html>
<html>
<head>
  <style>
    .normal-class {
      font-weight: normal;
    }
    .bold-class {
      font-weight: bold;
    }
  </style>
</head>
<body>
  <div class="normal-class">Normal font weight.</div>
  <div class="bold-class">Bold font weight.</div>
</body>
</html>