Slider STILL not responsive

I posted last week but haven’t received any support or reply to my post…

I tried all the suggestions in other forum posts without a solution. I need to launch this website this week. PLEASE HELP!

Website:

https://swannhomes.com

Current code in the modality-image-sliders.php file:

<?php while ( $modality_slider_query->have_posts() ): $modality_slider_query->the_post(); ?>
<?php $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), ‘single-post-thumbnail’ ); ?>
<li style=”background: url(<?php echo esc_url($image[0]); ?>) 50% 0 no-repeat;background-size:cover;”>