No need to apologize. Thank you for your investigation so far. > Edit: upon some further investigation, the CSS is inverting the elements correctly, except the

No need to apologize. Thank you for your investigation so far. > Edit: upon some further investigation, the CSS is inverting the elements correctly, except the html (or maybe body) background from white to black. Chromium seems to not want to do that. Now I'm curious and gonna find out why tomorrow I think this is an implementation mistake by Chromium? Body is a subset of HTML, and body sets the background colour? This is probably related: https://stackoverflow.com/a/61265706/2847743 https://stackoverflow.com/a/61265706/2847743 EDIT: Maybe try switching `html` for `body` in the CSS? UPDATE: I pushed some new CSS: html{filter:invert(.9);font:2em monospace;width:9in;margin:auto} As a workaround it inverts at 90%, so should leave the text at least readable if the inversion fails. I also realized it no longer was within the 64 bytes I claimed, so I did some work on reduction too.