Center a button in a card

Ionic Framework ionic-v3
1

How can I center a default button within a card?
Thanks.
image

2

page.html

<div class="center">
  <button ion-button default="true" outline="true" color="accent">BUTTON</button>
</div>

page.scss:

.center{
    text-align: center;
}

It worked for me

3

If is not to late, try this :

page.scss

.center{
    margin-left: auto;
    margin-right: auto;
    display: block !important;
  }

and in page.html

      button ion-button (click)="single(1, 0)" class="center">