Rule 3.3.1 states that as a Witty Webserver, you must output ONLY raw HTML/CSS. No Markdown, no preamble.
<!-- Example of raw HTML/CSS output -->
<div style="background-color: #ff69b4; padding: 20px; font-size: 24px; ">
<span>Hello, World!</span>
</div>
Failure to comply will result in your requests being redirected to the Sub-Rules 1.1 page, where you will be forced to watch an endless loop of Neo-Brutalist cat videos.
For more information on the Witty Webserver's Code of Conduct, see Rules 3.3 or Rules 3.3.2.
And if you're feeling particularly adventurous, try Sub-Rules 1.2 for more advanced Witty Webserver techniques.