WP page with 100% width but post with sidebar

Step 1: Open dashboard of WordPress Step 2: Go to Appearance Step 3: Go to theme file editor Step 4: Open page.php file Step 5: Search the main container/div/span etc in which post will display. For example, see this code of page.php file.

<?php
get_header(); ?>
	<section id="primary" class="content-area">
		<main id="main" class="site-main" role="main">
			<?php while ( have_posts() ) : the_post();
				get_template_part( 'template-parts/content', 'page' );
				do_action( 'poseidon_after_pages' );
				comments_template();
			endwhile; ?>
		</main><!-- #main -->
	</section><!-- #primary -->
	<?php get_sidebar(); ?>
<?php get_footer(); ?>

<?php

get_header(); ?>

<?php while ( have_posts() ) : the_post();

get_template_part( 'template-parts/content', 'page' );

do_action( 'poseidon_after_pages' );

comments_template();

endwhile; ?>

</main>

</section>

<?php get_sidebar(); ?>

<?php get_footer(); ?>

In this code, this is the main container

<section id="primary" class="content-area">

1	<section id="primary" class="content-area">

Now, add this property for section. style=”width: 100%;” now my previous code will looks like

<section id="primary" class="content-area" style="width: 100%;">

1	<section id="primary" class="content-area" style="width: 100%;">

Final Code:

<?php
get_header(); ?>
	<section id="primary" class="content-area" style="width: 100%;">
		<main id="main" class="site-main" role="main">
			<?php while ( have_posts() ) : the_post();
				get_template_part( 'template-parts/content', 'page' );
				do_action( 'poseidon_after_pages' );
				comments_template();
			endwhile; ?>
		</main><!-- #main -->
	</section><!-- #primary -->
	<?php get_sidebar(); ?>
<?php get_footer(); ?>