Yep. The offenders are usually really long un-line-breakable words, images, or videos. In this case we have: href="https://newcss.net/theme/terminal.css"> W

Yep. The offenders are usually really long un-line-breakable words, images, or videos. In this case we have: href="https://newcss.net/theme/terminal.css"> Which is not being allowed to break to a new line because it doesn't contain whitespace. A CSS rule can be used to allow it to break, though that can also have other, unwanted ramifications.