This should be a support ticket, but assuming you can't properly reach/use the support site lets try and list some possible causes/fixes you might not have checked yet.
To help you any further an absolute minimum requirement would be to know which browser you are using and if you have updated that browser. If any plugins/addins have been installed, make sure to disable those to make sure they do not cause any issues.
The domain you mentioned is not used on the forums so if you have issues on the forums too it is pretty safe to say that that is not the issue. The domain is mostly responsible for quick content delivery (like images). Quick googling found that it most likely currently belong to a company called StackPath which acquired the original company (Highwinds, hence hwcdn) of the domain back in 2017. None of this however should matter much, unless there are a lot of malware infected machines in your network, this could result in everything being blocked to prevent ddos and/or other botnet attacks.
If you issue is indeed the missing pictures and backgrounds then this domain being blocked is the cause/reason. The domain is NOT the same as the website you tried to reach, it is not a website. Down detectors are mostly used for websites, the structure of this domain is a bit more complicated. Just to be sure, the current background should be: https://n9e5v4d8.ssl.hwcdn.net/images/prime-access/primeaccesshildryn/background.webm
However none of this should make it impossible to access the website. It will look ugly without any background or pictures, but if that is the only thing failing to load you should still be able to access the store just fine. Please clarify (or screenshot) why you can't use the website. If you want actual adequate help your best chances are with an actual support ticket and not these forums.
TL;DR; yes the blocked IP is at least partially the cause of the missing stuff, try and contact support and provide a more detailed report so others (or at least support) can try and reproduce said issues.
Quimoth's post in Warframe Website Loading as Plain Text was marked as the answer