Finding the source in the header was obvious, but I can't figure how to decode that properly. I can see the rules for body{} and @keyframes{}, but no idea where all the text (the before/after rules) are hiding..
The header " The Page With No Code " is in the html::before content property.
The first paragraph "It all started when..." is in the body::before content.
The second paragraph "This web page has..." is in the body::after content.
And finally, the footnote "* Obviously there's some code somewhere..." is in the html::after content property.
I found those in the inspector, sure. But I can't find them in the base64 encoded header.
Edit: Nevermind. I tried like 10 different online base64 decoders before, till I found one wich didn't show just garbage (maybe they all hiccup on the emojis?), but even that one didn't decode properly as it seems. Either the eleventh one now told me the whole truth, or I should've used curl -i from the start instead of copy/pasting from Firefox's developer tools.
> The btoa() method creates a Base64-encoded ASCII string from a binary string (i.e., a string in which each character in the string is treated as a byte of binary data).