CSS code help for Cover Page page

Site URL: https://www.madisonavemedia.com/link-in-bio

Hello there! Hoping someone can provide the aha information I'm missing. Working on a cover page that's being used as a Link in Bio page. Previous coder on the project added code with script to allow for an extra button to be added, which is operating fine, but it is stacking the buttons side-by-side horizontally instead of vertically. Can anyone tell me how to modify the code to make that happen? 

Thanks in advance! 

Current code: 

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"> 
</script>

<li id="button2">
  <a href="https://www.madisonavemedia.com">
    Website
  </a>
</li>

$( "#button2" ).appendTo( $( "ul" ) );
$( "#button3" ).appendTo( $( "#button2" ) );

<script>
  $( document ).ready(function() {
    $( "#button1" ).appendTo( $( "ul" ) );
    $( "#button2" ).appendTo( $( "ul" ) );
    $( "#button3" ).appendTo( $( "#button2" ) );
  });
</script>

<style>
  .sqs-slide-wrapper[data-slide-type="cover-page"] .responsive-wrapper.stacked [data-slice-type="buttons"] ul li a, .sqs-slide-wrapper[data-slide-type="cover-page"] .responsive-wrapper.stacked [data-slice-type="navigation"] ul li a {
    margin-bottom:15px;  
}
</style>

Don't remove/edit any code

Add this to Cover Page Header

<style>
  .sqs-slide-wrapper[data-slide-type="cover-page"] .responsive-wrapper .sqs-slice ul {
    display: flex;
    flex-direction: column;
}

.sqs-slide-wrapper[data-slide-type="cover-page"] .responsive-wrapper .sqs-slice ul li {
    margin-bottom: 20px;
}
</style>

Thank you so much! It centered it, but now one is a little off on the left side. Is there a way to make sure they're all center aligned evenly?

3 hours ago, SmartGirl said:

Thank you so much! It centered it, but now one is a little off on the left side. Is there a way to make sure they're all center aligned evenly?

Use this CSS

<style>
  .sqs-slide-wrapper[data-slide-type="cover-page"] .responsive-wrapper .sqs-slice ul li {
    margin-left: 0 !important;
}
</style>

@tuanphanthat worked. You are wonderful, thank you!