Not a great solution when you simply want larger font size, but I use Stylish on pretty much every page. I use this: https://userstyles.org/styles/22794/a-dark

Not a great solution when you simply want larger font size, but I use Stylish on pretty much every page. I use this: https://userstyles.org/styles/22794/a-dark-hacker-news https://userstyles.org/styles/22794/a-dark-hacker-news Makes some of the font larger. You could modify that sheet.