W3.css

<div class="w3-row" style="display:flex; justify-content: center;">

<div class="w3-col m6 w3-dark-grey w3-center">

<p>Center using flex</p>

</div>

</div>

<section class="w3-row-padding w3-animate-opacity" style="background-color:#20262E; min-height: 80vh">

</section>

<td style="text-align: center; vertical-align: middle;"> {{i+1}}</td>

<a href="javascript:void(0);"> klik</a>