I'm agree with you on `{w}`.

But percentages **can** be above 100%. `width: 200%` means "twice as wide as the parent element" for example. 

On looking closer at the code, I noticed that reddit already has opacity which strangely allows for values 0-<2. Maybe it might be better to write an 0-1 macro or just go `num` everyhere, for consistency's sake? I'm not sure if the "as long as it doesn't break the browser" or the " as long as everything isn't weird" approach is better.

Also, I'm not exactly a dev poking at things according to an organized plan myself.