The thumbnails are blurry

@misaka1

While checking your site, it does not seems to be blurry. And since WordPress crops the image on lesser quality than uploaded, in some cases you might see it. So, to remedy it for your site, maybe use the child theme and then, change this filter as needed for your site: https://www.wpbeginner.com/wp-tutorials/how-to-increase-or-decrease-wordpress-jpeg-image-compression/ After that change is done, you need to regenerate the images used in your site. So, can you once check on those and confirm?

Thanks.