Strange thing, the HTML/CSS looks well done. And browsers should be able to know: "This is the same stylesheet I already cached, I can apply it already." - It might help to redundantly add the 'background="black"' attribute to the body tag.
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My first "Home Computer" (they are slightly different to "Personal Computers", I believe) was a C=16

You should try to get some Home Computers from Robotron, like KC-85/2 or KC-87, if you can. Extremely rare nowadays, especially outside the former GDR. Or a legendary PC-1715. There were even construction sets without keyboards, where people created some e.g. with model train signal box key groups.