Customize li and a elements in code

Hello, I am trying to customize the display of wp_list_pages on this piece of code. This basically formats a list of 100 pages into 3 columns.

It works except that I would like to add more space between the links list elements.

Does anyone know how to apply line-height: 150%; to the a elements on this code? I tried variants of a $style_2 but cant seem to find a way to make it stick.

<?php
	$list = wp_list_pages('title_li=&child_of='.$post->ID.'&echo=0');
	$list_elements = explode('</li>', $list);
	$num = count($list_elements)-1;

	$col = 4; //set the number of columns
	//$num_col = ceil($num/$col);
	$num_col = 35;
	$width = floor(100/$col)-1;

	$style = 'width:'.$width.'%;margin-right:3%;padding-left:1%;background: #ffffff;float:left;';

	for( $i=1; $i<$col; $i++) { $list_elements[$i*$num_col] = '</ul>
		<ul style="'.$style.'">'.$list_elements[$i*$num_col]; }
		$list = implode('</li>', $list_elements);
	?>

	<ul style="<?php echo $style; ?>">
		<?php echo $list; ?>
	</ul>