I don't have a clue how to code this stuff, I just stumbled through it until it started looking right. I don't even know if it will look right on other people's computers. Anyway, I hope this helps people and anyone is free to pick it up and run with it. There's definitely a few little things I wasn't able to tweak.

I'm providing two images in the screenshot. The first image how the page looks with the style. The second is with a few tweaks (light grey text is darker, less link-colour brought through) I did with the 'Colour That Site' add-on, the exported code for which is here: http://freetexthost.com/czapfmc1qx

Version 1: 4th Feb 2014
Version 2: Sorted the global thing out. Should only affect Twitter now.