I’m curious, how is the sign coded? Is the textbox and text a PNG image or is it just text in HTML?
Also, which font do you use? I think it’s your own. Can I download it?
There are no HTML elements used except for when you load/save a level; Everything else is just rendered to a <canvas> element. The font is my own, but it's not very usable outside of the game, I'm afraid.