Website isn't working:

It looks like it redirects back to itself:
curl -I https://reactjs.org/
HTTP/2 301
date: Mon, 07 Dec 2020 20:44:13 GMT
content-type: text/plain
content-length: 36
cache-control: public, max-age=0, must-revalidate
location: https://reactjs.org/
server: cloudflare
cf-ray: 5fe1155539f938cd-ATH
Same here. Tried in Firefox and Chrome in private tabs.
We're investigating. Seems like it's specific to Europe somehow.
Appears fixed. We'll follow up with our provider to figure out what happened. Thank you for reporting.
While the static HTML loads now, the JS bundle is still redirected many times before it fails:

It's not as obvious that it's broken but any part relying on JS doesn't work like https://github.com/facebook/react/issues/20404
ID (x-nf-request-id) of the failed request: 8691d43d-6345-42d6-9b4c-bd8bd584749b-17118896
For anybody affected, you can use https://5fcecf86d72a1500d6cda8e6--reactjs.netlify.app/docs/getting-started.html in the meantime. That's the same site just from a different URL.
Confirming the site is still broken regarding JS bundle. HTML loads, but even the right panel navigation does not.
Tried in Chrome Version 86.0.4240.183, I am based in Czechia (Central Europe region)
We've reached out to our provider's support channel but they're probably asleep now. So this will likely persist until the evening.
Sidenav links not working
Please use the mirror in the meantime: https://5fcecf86d72a1500d6cda8e6--reactjs.netlify.app/
We're aware that everything that relies on JS (including sidenav, code examples, and some formatting) is broken. We're in contact with our provider's support.
Most helpful comment
Please use the mirror in the meantime: https://5fcecf86d72a1500d6cda8e6--reactjs.netlify.app/
We're aware that everything that relies on JS (including sidenav, code examples, and some formatting) is broken. We're in contact with our provider's support.