When I deploy to Netlify, the page loads but the theme does not show properly.
Everything looks fine when I deploy locally with hugo serve
Any thoughts on what may be causing this? I set the base_url up properly.

here is the website if that is helpful
https://maximilianrohde.com
and the GitHub page with the source is here
https://github.com/maxdrohde/website
Inspecting your website I saw that both CSS and JS content are suffering a redirect and so being blocked by CORS rules.

You have configured your base_url as https://www.maximilianrohde.com. I think It should work fine if you remove the subdomain www, so changing base_url to https://maximilianrohde.com.
That fixed it, thank you!
Most helpful comment
Inspecting your website I saw that both CSS and JS content are suffering a redirect and so being blocked by CORS rules.
You have configured your
base_urlashttps://www.maximilianrohde.com. I think It should work fine if you remove the subdomainwww, so changingbase_urltohttps://maximilianrohde.com.