Low resolution images

I use images on my portfolio site, but my images are of poor quality. How can i fix this. I make my designs using Figma and I can export images in desired size and resolution. But when I upload it to the site, the image quality decreases. You can see the pictures on the site below.

https://shaig-portfolio.webflow.io/case-study

Here is my read-only link - https://preview.webflow.com/preview/shaig-portfolio?utm_medium=preview_link&utm_source=designer&utm_content=shaig-portfolio&preview=4314f6cb02ab353e0b7fc02d52435e9d&pageId=60acb7c1bae02f19eebb5cfe&workflow=preview