If you had difficulty accessing the site today, it was due to downtime with Microsoft Azure datacentres. Potentially thousands of websites were offline with this issue for around 2.5hrs.
Matters may not be over entirely as I write this. Azure are still cautiously labelling our region as "Warning" status on their service status page: https://azure.microsoft.com/en-gb/status/.
Follow that page for updates if anything happens again. We are in the "West Europe" region.
In the meantime, we are already thinking of ways we can create some kindof backup service in the event that this ever happens again. We didn't expect it would be necessary in the cloud, as availability is generally very reliable with cloud services, but apparently it will. E.g. we may set up services in multiple regions so that we can avoid being dependent on one region.