Code samples and fixed width web sites don't mix, even if the code samples have horizontal scroll bars, which everyone hates anyway. This nleach.com site has a fixed width of 70em (which seems awfully low in general, and is measured with the width of the non-fixed font in the outer container, so the effective length of the fixed area is only 44 chars, at least on my system), and the longest code line is 170 characters. If anything, the user should be able to resize their browser window (rather than have to edit the CSS) to make it wider to see the content.

(I also wish HN had a more dynamic width for fixed width content and/or had a different way to specify fixed width font than just indentation, since people also use indentation for bulleted lists, which makes them really hard to read, especially on smaller screens).