Feature request: dark user interface

[Yue-Zhengyuan]

I would like to be able to use quiver in a dark theme. Browser plug-ins like the Dark Reader does not work well with arrows in the commutative diagram, so maybe a native dark mode is the best solution.

[varkor]

If someone makes a pull request for this feature, I would be willing to merge it, but I won't prioritise this feature myself.

[kpa28-git]

I guess the default css coloring for the labels changes based on theme, but not so for the arrows. Wonder if a common default color property for labels and arrows would fix it

[UlyssesZh]

Also, it would be good if the embed can also detect dark theme according to prefers-color-scheme.