Alterar tamanho de rodapé

Olá!

O rodapé do meu tema é dividido em 4 blocos.
Como faço para alterar para apenas um da largura da página (728×90, por exemplo)?

Código:

</div><!–.container–>
<footer id=”footer”>
<div class=”container_12 clearfix”>
<div class=”clearfix”>
<div class=”grid_12″>
<div class=”bottom-widget clearfix”>
<div class=”grid_2 alpha”>
<div class=”widget-footer”>
<?php if ( ! dynamic_sidebar( ‘1Footer’ ) ) : ?>
<!–Widgetized Footer–>
<?php endif ?>
</div>
</div>
<div class=”grid_2″>
<div class=”widget-footer”>
<?php if ( ! dynamic_sidebar( ‘2Footer’ ) ) : ?>
<!–Widgetized Footer–>
<?php endif ?>
</div>
</div>
<div class=”grid_3″>
<div class=”widget-footer”>
<?php if ( ! dynamic_sidebar( ‘3Footer’ ) ) : ?>
<!–Widgetized Footer–>
<?php endif ?>
</div>
</div>
<div class=”grid_5 omega”>
<div class=”widget-footer”>
<?php if ( ! dynamic_sidebar( ‘4Footer’ ) ) : ?>
<!–Widgetized Footer–>
<?php endif ?>
</div>
</div>
</div>
</div>
</div>
<div class=”clearfix”>
<div class=”grid_12″>
<div id=”copyright” class=”clearfix”>
<?php if ( of_get_option(‘footer_menu’) == ‘true’) { ?>
<nav class=”footer”>
<?php wp_nav_menu( array(
‘container’ => ‘ul’,
‘menu_class’ => ‘footer-nav’,
‘depth’ => 0,
‘theme_location’ => ‘footer_menu’
));
?>
</nav>
<?php } ?>
<div id=”footer-text”>
<?php $myfooter_text = of_get_option(‘footer_text’); ?>

<?php if($myfooter_text){?>
<?php echo of_get_option(‘footer_text’); ?>
<?php } else { ?>
/” title=”<?php bloginfo(‘description’); ?>” class=”site-name”><?php bloginfo(‘name’); ?> © <?php echo date(“Y.”); ?>
/privacy-policy/” title=”Privacy Policy”><?php _e(‘Privacy Policy’, ‘theme1677’); ?>
<?php } ?>
<?php if( is_front_page() ) { ?>
<!– {%FOOTER_LINK} –>
<?php } ?>
</div>
</div>
</div>
</div>
</div><!–.container–>
</footer>
</div><!–.content-box–>
</div><!–#main–>
<?php wp_footer(); ?> <!– this is used by many WordPress features and for plugins to work properly –>
<?php if(of_get_option(‘ga_code’)) { ?>
<script type=”text/javascript”>
<?php echo stripslashes(of_get_option(‘ga_code’)); ?>
</script>
<?php } ?>