<div class="container">
  <button class="cdt-btn cdt-btn-full-rounded">Fully rounded button</button>  
  <button class="cdt-btn cdt-btn-rounded">Rounded button</button>  
</div>
.container {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}