<section class="content">
   <div class="container-fluid">
      <div class="row">
         <div class="col-md-6">
            <div class="card card-success">
               <div class="card-header">
                  <h3 class="card-title">Different Height</h3>
               </div>
               <div class="card-body">
                  <input class="form-control form-control-lg" type="text" placeholder=".form-control-lg">
                  <br>
                  <input class="form-control" type="text" placeholder="Default input">
                  <br>
                  <input class="form-control form-control-sm" type="text" placeholder=".form-control-sm">
               </div>
            </div>
         </div>
      </div>
   </div>
</section>