Your solution works from my end. Please try one of the following steps to move forward.
Click on the “Restart Step” button and force a refresh of your page with CTRL-F5 then try to paste the code in again.
or - Try the step in incognito or private mode.
or - Disable any/all extensions that interface with the freeCodeCamp website (such as Dark Mode, Ad Blockers, or Spellcheckers), and set your browser zoom level to 100%. Both of these factors can cause tests to fail erroneously.
or - Ensure your browser is up-to-date or try a different browser.
Actually it is just that this question triggered something because of the way it checks for the style element. Some other steps may also trigger differently for different extensions. Essentially the browser extensions are manipulating the html and css in the page so when you try to submit, the manipulated code is being checked by the fCC test. And that is why it fails.