About the design, why not move the website to Wordpress and use Elementor(Elementor is free) to make a beautiful page design?
I'm not sure all that work is necessary.
The page, while not looking "fancy", certainly gets across the main message. "This *was* a fake site, if you downloaded from it, you've downloaded a fake version of Electrum. Here are some helpful links".
I don't think it needs a "beautiful" design to get that message across. In fact, it might be better that it doesn't look fancy. One could argue that people are more likely to notice something that doesn't look "normal" and maybe take the time to stop and read what looks like "error messages"... as opposed to thinking they just clicked on the wrong thing and click "back" to return to search results etc.