This is a minor point, but the website has no max-width. On high resolution displays this leads to very long paragraphs.

Too wide – if a line of text is too long the reader’s eyes will have a hard time focusing on the text. This is because the line length makes it difficult to gauge where the line starts and ends. Furthermore it can be difficult to continue onto the correct line in large blocks of text.

https://baymard.com/blog/line-length-readability