[andrewparker]

CSS (like all written works) is copyrightable, so if there is clear evidence that the CSS was copy/pasted, CB Insights would have a case on that basis. Damages would be negligible, so it would not be a case worth pursuing.

[macmac]

Not all written works are copyrightable. Even in the US which is fairly lax about granting copyright, a work must fulfill certain criteria to be copyrightable, cf here for a good overview https://www.lib.purdue.edu/uco/CopyrightBasics/basics.html

[bhayden]

Since titles and short phrases aren't copyrightable, could I start a tech news blog, have all of the exact same stories and titles that Engadget uses, and write my own content for each story and not being infringing on their copyright?

[macmac]

You could try, and Engadget would probably not, if they hire a good law firm, use copyright to try to stop you. They could however potentially use other parts of the law including, depending on the jurisdiction, rules on unfair competition, passing off etc.