[Grom_PE]

I think the main cause of black rectangle is the lack of support for nested CSS. At least that's what I'm seeing in my browser.

[mrled]

Ohhh interesting. To anyone hitting this, I'm curious what specific browser you're using - I thought it was available ~everywhere now? https://caniuse.com/css-nesting

[everybodyknows]

Seeing only inverted smilie over black background on my iPad, dark mode or light both.

[LoganDark]

It's only been available everywhere since like 2023. My browser happens to be from 2022.