Add css class to Pagination?

I've been using this code:

$current_page = get_query_var('paged');
$current_page = max( 1, $current_page );

$per_page = 12;
$offset_start = 1;
$offset = ( $current_page - 1 ) * $per_page + $offset_start;

$post_list = new WP_Query(array(
    'cat'            = -15,
    'posts_per_page' = $per_page,
    'paged'          = $current_page,
    'offset'         = $offset, // Starts with the second most recent post.
    'orderby'        = 'date',  // Makes sure the posts are sorted by date.
    'order'          = 'DESC',  // And that the most recent ones come first.
));

// Manually count the number of pages, because we used a custom OFFSET (i.e.
// other than 0), so we can't simply use $post_list-max_num_pages or even
// $post_list-found_posts without extra work/calculation.
$total_rows = max( 0, $post_list-found_posts - $offset_start );
$total_pages = ceil( $total_rows / $per_page );

if ( $post_list-have_posts() ):
    while ( $post_list-have_posts() ):
        $post_list-the_post();


        // loop output here
    endwhile;

    echo paginate_links( array(
        'total'   = $total_pages,
        'current' = $current_page,
    ) );
endif;
wp_reset_postdata();

This is from this answer: https://stackoverflow.com/questions/49227520/how-can-i-paginate-wp-query-results-when-theres-an-offset

Would it be possible to add a css class around this line?

   echo paginate_links( array(
        'total'   = $total_pages,
        'current' = $current_page,
    ) );

So it would be something like:

div class=col-lg-12
   echo paginate_links( array(
        'total'   = $total_pages,
        'current' = $current_page,
    ) );
/div

Everything I've tried has led to a Wordpress Error Page

Thanks!