Align Posts in a Row [Posts in Columns ] and make thumbnail Small

i have made a function.php file and i want post in columns and thumb nails to appear small

/*** Custom Loop ***/

function Last5posts()
{
    $args = array( "showposts" => 5 );
    query_posts($args);

    $content = "";

    if( have_posts() ) : 

        while( have_posts() ) :

            the_post();
            $link = get_permalink();
            $title = get_the_title();
            $date = get_the_date();
            $thumbnails =get_the_post_thumbnail();
          $excerpt= get_the_excerpt();               

            $content .= "<div style='padding: 5px; border: 1px solid red'>";
            $content .= "<h3><a href='$link' target='_top'>$title / $date / $thumbnails</a></h3>\n";
            $content .= "<p class='excerpt'>" . get_the_excerpt() . "</p>";
            $content .= "</div>";

        endwhile;

        wp_reset_query();

    endif;

    // Leave one line commented out depending on usage
    echo $content;   // For use as widget
    //return $content; // for use as shortcode
}
add_shortcode('Last5Posts', 'Last5posts' );