I can't do this layout

[baccdo]

Hello. I need to do this in a specific category. Can someone tell me what I doing wrong? this is my code. my image layout.

I want to place the div post-box next to each other

Thanks

category-special.php

<?php get_header(); ?>

        <!-- Row for main content area -->
        <div id="content" class="eight columns">

            <div class="post-box">
<?php /* If there are no posts to display, such as an empty archive page */ ?>
<?php if (!have_posts()) : ?>
    <div class="notice">
        <p class="bottom"><?php _e('Sorry, no results were found.', 'reverie'); ?></p>
    </div>
    <?php get_search_form(); ?> 
<?php endif; ?>

<?php /* Start loop */ ?>
<?php while (have_posts()) : the_post(); ?>
    <article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
        <header>
            <h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
        </header>
        <div class="entry-content">
    <?php if (is_archive() || is_search()) : // Only display excerpts for archives and search ?>
        <?php the_excerpt(); ?>
    <?php else : ?>
        <?php the_content('Continue reading...'); ?>
    <?php endif; ?>
        </div>
        <footer>
            <?php $tag = get_the_tags(); if (!$tag) { } else { ?><p><?php the_tags(); ?></p><?php } ?><?php edit_post_link(); ?>
        </footer>

    </article>  
<?php endwhile; // End the loop ?>

            </div>

        </div><!-- End Content row -->

        <?php get_sidebar(); ?>

<?php get_footer(); ?>