[flagged]

They do not use strikethrough but:

    text-decoration-line: underline
    text-decoration-style: solid
    text-decoration-thickness: auto
    text-underline-position: under

Please don't complain about tangential annoyances—e.g. article or website formats, name collisions, or back-button breakage. They're too common to be interesting.

https://news.ycombinator.com/newsguidelines.html

Most likely a CSS rendering issue. I'm seeing proper/normal output on macOS Safari.

It's because of some bad offset between background and text...

Exactly, the issue is at:

  text-underline-position: under;

It's clearly not intentional - it's a glitch, probably in the font.

Huh. I'm not seeing anything that looks like what you're describing.

I also see it, Firefox on linux.