poor featured image quality display in Portfolio page

Here is the code I wrote to make my portfolio display 2 items in a row, but it seems sacrificed the display image’s quality.
How can I improve the image quality that displayed in portfolio page (not the home one but the one in the top menu) ?

.post-type-archive-jetpack-portfolio #page #main article,
#page .shapely_home_portfolio .row.masonry 
           .masonry-item.project.fadeIn.masonry-brick 
{
    position: static !important;
    width: 50%;
}

Please help, thanks in advance.

Hello there,

I hope you are doing well today.

Could you please provide a link to the website so that I can have a look at the images?

In the meantime, please try using the following plugin to improve your image quality:

Best Regards,
Support

Hello,

Thank you for the reply! Sure, the link is http://ericalong.space/portfolio/. You can see the pictures are 2 in a row but quality is pretty fuzzy…

Thanks!

Hello there,

Thanks for the link.

I have checked the webpage and the image resolution appears to be 555 x 348 px. Could you please replace the image with one of a larger resolution then check to see the results.

Best Regards,
Support

Hi,

So I tried a larger size image (11MB), but it’s still very blurry…
I also tried the plugin you mentioned but it’s for the image compression rather improving the image quality which I want for my featured image of the portfolio display…

Let me know if there are any other ways can solve this problem? Thanks!!