You are free to steal this website's source code that is available in the combinoob.github.io repository of my Github profile. If you use the exact same format and/or styles from style.css or sript.js of the repository, please mention this or use the following for the footer of your website.
<footer class="footer">
<div class="container text-center">
<span class="text-muted">© <a href="https://combinoob.github.io">Nirjhar Nath</a></span>
</div>
</footer>
If you like the dark mode as default, you can replace <html lang="en" class="light"> by <html lang="en" class="dark"> in line 2 of every .html file of the combinoob.github.io repository.
I had been considering updating my website for a while now. My old website still lives in the old-website repository of my GitHub profile. You are allowed to use the source code of this website also, including the above footer in the .html file of your website.