2.3.64 adapts to Lichess theme changes

Lichess is changing the way the handle themes (dark, light, etc.). It should not affect LiChess Tools except some weird colors in some places. In 2.3.64 I fixed it, but I don't know if the fixes are stable or if Lichess is not going to change more stuff.

So please let me know if anything looks wrong. Thanks!

When it happens, I take off permission to Lichess tools on lichess temporaily just to make sure it is lichess only that creates the behavior I see. Then I put it back on. (reloading for each transition).