pre-elements are unreadable with dark fallback-theme.

[tastytea]

The pre elements are assigned a background-color but no color. This results in unreadable text for me.

To reproduce, configure your browser to use white text on black background as fallback.

If you want the background to be slightly darker without having to set colors for the whole page, you can use the alpha-channel and set the color to #0002 or so.