cargo-timing.html supports dark mode

[ahaoboy]

Problem

For users using dark mode, opening cargo-timing.html is very glaring

I can use some browser ext to force the web page to switch to dark mode, but the canvas will still be white background.

Proposed Solution

For web pages, there is already prefers-color-scheme

https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-color-scheme

For canvas, maybe just invert the basic white and black, and keep the other colors?

Notes

No response

[weihanglo]

Thanks for the proposal. This is a good feature, though I don't think any of the maintainers has time to either mentor or design it.