The site has been updated and moved to a new server so you may have to sign in again. Apologies for the inconvenience.
Please note, you only need to sign in, not sign up!
You may find you occasionally get signed out whilst I address any issues that come up over the next couple of days. Apologies again.
Thanks @Calamari. The server it was on was getting old and is being retired in January, and quite a lot of things were broke on the site like youtube videos and capital letters! These are now fixed. Also it works a bit better on mobile and smaller devices. I didn't want to change it too much in one go though.