[WordPress]ウィジェットエリアでfooterを3カラムに

//widget 追加
add_action(
	'widgets_init', 
	function(){
		register_sidebar(array(
			'id' => 'org-1',
			'name' => 'footer左',
			'before_widget' => '<div class="box1" >',
			'after_widget' => "</div>",
			'description' => 'footer左側のウィジェット',
		));
		register_sidebar(array(
			'id' => 'org-2',
			'name' => 'footer中',
			'before_widget' => '<div class="box2" >',
			'after_widget' => "</div>",
			'description' => 'footer真ん中のウィジェット',
		));
		
		register_sidebar(array(
			'id' => 'org-3',
			'name' => 'footer右',
			'before_widget' => '<div class="box3" >',
			'after_widget' => "</div>",
			'description' => 'footer右側のウィジェット',
		));
	}
);

<div id="new-foot">
<?php if(is_active_sidebar('org-1','org-2','org-3')) : ?>
		<div id="my_widget-1">
		<?php dynamic_sidebar('org-1'); ?>
		</div>
        <div id="my_widget-2">
		<?php dynamic_sidebar('org-2'); ?>
		</div>
        <div id="my_widget-3">
		<?php dynamic_sidebar('org-3'); ?>
		</div>
 </div>       
<?php endif; ?>

<?php
/**
 * @package Welcart
 * @subpackage Welcart Voll
 */
?>
		</div><!-- #main -->
		<?php if(! wp_is_mobile()): ?>
			<div id="toTop" class="wrap fixed"><a href="#masthead"><i class="fa fa-angle-up" aria-hidden="true"></i></a></div>
		<?php endif; ?>
		<footer id="colophon" role="contentinfo">
			<div class="inner cf">			
					<?php get_template_part( '任意のページ名' ); ?>				
		</div><!-- .inner -->
            <p class="add">CopyrightcOnline Shop All Rights Reserved.</p>
		</footer><!-- #colophon -->
	</div>	
	<?php wp_footer(); ?>
</body>
</html>

@media screen and (min-width: 38.75em) {
#my_widget-1,#my_widget-2,#my_widget-3{width:30%;float:left;}
#my_widget-1,#my_widget-2{margin-right:5%;}
}