For those looking to jump on Steam right now in the late night/early morning period, you will sadly be out of luck. As of right now, it appears that Steam is completely down for the time being.
The website and store appear to have gone down around 4 am ET for everyone, making it impossible to access the store through the app or even the website itself. This means that you cannot even view anything on the store, much less try and buy anything.
When trying to visit the website, you will receive a “Service Unavailable” message, showing that the entire website is down rather than just a portion of it. It isn’t just the Steam Store, but also Steam Communities that are also down currently.
While services like Xbox Live and PSN seem to have issues quite often, Steam as a whole typically has much less issues. It is always possible that Valve could be doing maintenance on the system, but one would think that they would have given a heads up.
The good news is that this downtime has occurred in the best possible time for those in the US overall, so hopefully they can get everything back up and running soon enough to where those looking to play some games later today will not have any issues at all.