cn.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>ComputerNetworkCourseContent</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.2/dist/css/bootstrap.min.css">
</head>
<body style="background-color: black;">
    <div class="d-grid gap-2 col-6 mx-auto" >
        <button class="btn btn-primary" type="button" style="margin-top: 40%;margin-bottom: 20px;"><a href="./module1.html" style="text-decoration: none;color:white;">Module-1</a></button>
        <button class="btn btn-primary" type="button" ><a href="./module2.html" style="text-decoration: none;color:white;">Module-2</a></button>
      </div>
</body>
</html>