[XKit Preferences] Dark Mode Update

[motackt]

Put in some logic (using checkboxes) for the XKit Control Panel to:

1. Match the current Tumblr colour palette. True Blue, Cement, and Canary all tell XKit to use the default light theme, while Dark Mode, Low-Contrast Classic, and Cybernetic all tell XKit to use this new dark mode.
   • So if the Tumblr colour palette changes, then the XKit Control Panel will update next time the user opens the Control Panel.
2. Always use dark mode no matter what.

I'm not sure exactly how to get the Dark Mode to not be on by default, and how to get Match Tumblr Theme to be on by default, unfortunately. Advice?

Updated some class styles with items that weren't previously defined and so defaulted to black (not very clear against a dark background), and also added more variables because white box-shadows are not really a great design choice in dark themes.

As a bonus, changed the default and kernel extension icons to SVGs for crispness and space!

[AprilSylph]

why not just always match the current tumblr colour scheme?

[motackt]

Nobody knows what the user wants more than they do! I can't personally imagine why I would want a light Tumblr colour palette and a dark XKit theme, but I'm sure someone out there might prefer that setup.

[AprilSylph]

right, but this is using the tumblr palette to set the xkit palette in the first place, right? they should either be coupled properly or completely decoupled

[motackt]

When opening the Control Panel or clicking the Match Tumblr Theme checkbox, it checks for whether the Tumblr colour palette is light or dark using --rgb-black, and then sets dark mode based on that.

When clicking the Enable Dark Mode checkbox, it simply sets dark mode.

Match Tumblr Theme has priority over Enable Dark Mode, so it disables the checkbox (using CSS, so not a great disable tbqh) when it's on.

I suppose I'm not really understanding why it needs to be one or the other :?

[AprilSylph]

ah, nevermind. i misunderstood your problem of dark mode being on by default.

[motackt]

No problem! I think Match Tumblr Theme should be on by default, and Enable Dark Mode should be off by default, but I'm not sure how to set that in the javascript file ^__^;

[motackt]

Continued in #2024 to keep up with current master.