Export pdf file code background color problem

[OneCoder]

Hi,

Apologies if this is the wrong section.
When I export PDF with a black background, why is the block of code in it white instead of black in preview mode.
But it changed the style when I exported it:

Because I was limited to uploading only one image,the color of the code block is the same as the color of the edge of the image above.

I tried to change the userstyle.css:

code {
	background-color: #222222;
	white-space: pre-wrap;
}

It only changed the code's color but not the block.

[OneCoder]

It looks like this when previewing in the editor: