<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css"> <script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script> <script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script> <!------ Include the above in your HEAD tag ----------> <div class="container"> <div class="registration mx-auto d-block w-100"> <div class="page-header text-center"> <h1>Sign up</h1> </div> <form id="member-registration" action="/astroidnew/index.php/pages/register?task=registration.register" method="post" class="form-validate form-horizontal well" enctype="multipart/form-data"> <fieldset> <legend>User Registration</legend> <div class="form-group"> <label for="exampleInputPassword1">Name *</label> <input type="text" class="form-control" id="exampleInputPassword1"> </div> <div class="form-group"> <label for="exampleInputPassword1">Username *</label> <input type="text" class="form-control" id="exampleInputPassword1"> </div> <div class="form-group"> <label for="exampleInputPassword1">Password *</label> <input type="password" class="form-control" id="exampleInputPassword1"> </div> <div class="form-group"> <label for="exampleInputPassword1">Confirm Password *</label> <input type="password" class="form-control" id="exampleInputPassword1"> </div> <div class="form-group"> <label for="exampleInputEmail1">Email Address *</label> <input type="email" class="form-control" id="exampleInputEmail1"> </div> <div class="form-group"> <label for="exampleInputEmail1">Confirm Email Address *</label> <input type="email" class="form-control" id="exampleInputEmail1"> </div> <div class="d-flex justify-content-between align-items-center"> <div class="form-group d-flex justify-content-start"> <button type="submit" class="btn btn-primary">Submit</button> </div> <div class="form-check form-group d-flex justify-content-end"> <a href="#">Sign in instead</a> </div> </div> </fieldset> </form> </div> </div>

@media (min-width:767px){ .registration{ max-width: 400px; } }