What the CSS?

Aside from this article, why css as a whole is such a unmenagable mess? The whole frontend "separation of concerns" is fucking stupid: data - html, look at any modern website - you see div soup holding no data, css - try making some runtime customizabily eg. change color, layout on ie11, js - contrary to popular opinion, js does what it should do :p

Maybe it was holding water when all pages was as complex as hacker news but currently we need something which is little more sensible

I'm immensely confused by this: `It's totally ok to write class="75%" if you define it as .\35 0\%{} in CSS.` How is this:

    .\35 0\%{}

turned into "75%"? It looks more like it would turn into "50%". Why is there a space after the 5 (wouldn't that mean you're finished talking about the class and have moved on to explaining a descendent element?) and what does \3 mean?