I tried designing one of those SSH attack-map websites based around the interfaces in 2001: A Space Odyssey, like these here[1]. It was difficult, I was trying "emulation of low-tech methods" as you said. I think if you could run a shader over top of a web page it'd be easier. I didn't research it that deeply but I don't think that's really a supported use case for web shaders, it would block inputs from using the website if I'm understanding correctly.

1. https://ilikeinterfaces.com/tag/2001-a-space-odyssey/