Display WP posts in 3 responsive columns

<?php
    $the_query = new WP_Query("showposts=6&cat=1&orderby=rand");
    while ( $the_query ->have_posts() ) {$the_query ->the_post(); $i++;
        if ($i == 1){echo "<div class=row-fluid>";}
        ?>
            <div class="span4">
                Random Post <?php echo $i ; ?>
            </div>
        <?php
        if ($i == 3){echo "</div><div class=row-fluid>";}
        if ($i == 6){echo "</div>";$i=0;}
    }
    wp_reset_postdata();
?>