Better yet, let us choose the features we want on our tests.

Someone did a dark version of the site.
https://userstyles.…

To use it, you just need to install a browser extension:
Firefox: https://addons.mozi…
Chrome: https://chrome.goog…

Building your custom style is easy. It's a great way to experiment UI changes. If a new style has some traction, I will be fine integrating it to the site.

I love Stylish, probably the best browser extension dealing with css and etcetera.
I always used it to change fonts but I just didn't think about changing the colour scheme for my favourite websites.
The scripts I think were perfectly fine although I would have changed span to #fff (white) to make all the quotations white so that it stands out.

span {
color: #fff !important;
}

Trying the dark style now, looks nice! I wonder how someone would go about making their own style?

Making an own style isn't a big complex concept, it mostly starts from changing little pieces of information in the "css" file that essentially defines the look of the site.
You can call it programming but it mostly involves installing some type of css editor, in my case, Stylish, and then inspecting elements that needs to be changed and then googling what the valid cases and values are.
E.G: If the code says (font something something)= YuGothic,
you just change whatever value, in this case YuGothic, to something you want.