I've been using My Style [1] for blogs like this. On Dan's, I added the following tweak:

    body { max-width: 768px; margin: 32px auto; font-family: Helvetica; font-size: 20px; }

It really helps my focus on long articles that are otherwise hard on the eyes. I know there's Readability and all, but this extension works without any additional steps once set up.

[1]: https://chrome.google.com/webstore/detail/my-style/ljdhjpmbn...