Axiomatic CSS

Axiomatic CSS is real and CSS doesn’t have to be a nightmare.

Get over your CSS hatred and embrace the CSS Layout Engine.

First I want to introduce the concept of a practicable notion. This is a human behavior. Example: “If I want food, and I prepare food, I will have satisfied my desire to have food.”

Practicable notions are particularly useful in systems that can be reasoned about. The level of granularity at which we approach these notions determines the outcome. Good software engineering design, largely, emerges out of building logical systems from smaller groupings of these notions.

I often see people writing CSS without a strong understanding of the system or an expectation that it should be like the other software-building systems that we have.

It would be great if the web had a layout engine that wasn’t CSS. But right now it doesn’t. And what we can achieve with CSS is actually pretty amazing.

If you don’t like what we can achieve with CSS, you’re probably either at the wrong job, haven’t written CSS long enough, or piles of terrible CSS have been heaped on you to the tune of psychological damage and violent-crime victim-like hostility to the engine or writing some of the configuration for the layout.

CSS is just configuration for the CSS Layout Engine.

CSS As Configuration

When you think of CSS as Configuration hopefully it breaks your mind out of “PSD Thinking” and toward systems thinking. I think the difference is that PSD-Think is overly concerned with matching the PSD to the tune of expressing every little detail as configuration right there within as small a region as the author of the code can see.

Systems thinking with CSS is about drawing out some of the rules of the system and collecting them at the appropriate level so that every little detail of the system can be expressed in a way that only puts the code [yeah, the configuration] at the level where it must exist.

It’s about finding the rules of the system. When you can find the system rules and express them as code, you get systems. When you don’t find the rules, or don’t express them in code, you get a mess.

All too often I see developers writing CSS where every line is an exception because there are no rules. This is a mess, and I think it leads to grand mass aversion, only founded insofar as it has never been remediated.

Axiomatic CSS

The true gem in Heydon Pickering’s 2014 Axiomatic CSS1 article wasn’t the “lobotomized owl selector”, though it is a really cool construct.

Here’s the real value proposition: you can think about writing CSS in ways that will affect the system more powerfully, and in many cases you should.

Here are some scenarios where I’d consider more systemic thinking about CSS:

  1. Axiomatic CSS and Lobotomized Owls, Heydon Pickering↩︎


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