How to add sidebar at single.php in Wordpress -

i'm having problem when comes adding sidebar @ single.php. included

<?php get_sidebar(); ?> 

but seems appear below , content(blog post) still @ middle of whole page. i've tried check of previous forum none of them helped me figure out.

here's single.php

<?php /**  * template displaying single posts.  *  * @package tesseract */  get_header(); ?> <div id="primary" class="full-width-page">     <main id="main" class="site-main" role="main">      <?php while ( have_posts() ) : the_post(); ?>          <?php get_template_part( 'content', 'single' ); ?>          <?php tesseract_post_nav(); ?>          <?php             // if comments open or have @ least 1 comment, load comment template             if ( comments_open() || get_comments_number() ) :                 comments_template();             endif;         ?>     <?php comments_template(); ?>     <?php endwhile; // end of loop. ?>      </main><!-- #main --> </div><!-- #primary --> <?php get_sidebar(); ?> <?php get_footer(); ?> 

the logical reason happen there isn't enough room both main content , sidebar appear next each other. check width of sections in stylesheet , make necessary changes styles.