Yeah, according to https://book.mixu.net/ this was written in 2015, at nine years old I'd be worried about this not being super useful for modern CSS.

The core of CSS, and principles that new CSS features follow, haven’t really changed in decades. It’s just been built upon and refined.

Given these articles are looking an underlying principles of the CSS layout process, I wouldn’t worry about it being out of date. Everything it covers certainly hasn’t changed (because so many websites would be very broken if they had), and new CSS will be built on the fundamental principles laid out here. So even if it doesn’t cover stuff like grid, it will definitely provided much need background information to help you understand the details of how grid works, generally build a better intuition around how both old and new CSS features work.

The core of CSS absolutely has changed. Unless you're building a mobile-only site, you're likely using media queries today to target multiple viewport sizes, which wasn't on anybody's radar in 2006.

Much of these changes in CSS have simply beeen obscured by improvements in cross-browser compatibility and use of layout frameworks that hide all the complexity behind simple class names.

In the 2000s, sites were built with the <table> element to simulate a grid.

In the 2010s, it changed twice, first by using floats and CSS reset methods to create responsive columns. Then that went away in favour of Flexbox and Grid, which now have wide browser support.

If you're building sites for IE6 compatibility, then things probably haven't changed much.

> The core of CSS absolutely has changed. Unless you're building a mobile-only site, you're likely using media queries today to target multiple viewport sizes, which wasn't on anybody's radar in 2006.

These two sentences don't really follow from each other? Gaining additional features isn't necessarily the same thing as the core of a technology changing. The actual core of CSS would be things like its box model, stacking contexts, specificity, etc.

And ironically you can in fact achieve responsiveness without using media queries. That's arguably the entire point of more sophisticated layout algorithms like flexbox and grid.

> And ironically you can in fact achieve responsiveness without using media queries. That's arguably the entire point of more sophisticated layout algorithms like flexbox and grid.

Flexbox and Grid? They're certainly helpful, but not required! I remember trying to achieve a responsive layout in IE6 that IIRC only had limited support for min-width/max-width. It was possibly even back then, although I can't remember how it was done off the top of my head.

Definitely! When I say it's the point of flexbox and grid, I mean that they remove the need for the dev to do the manual width and bounds calculations (much like being able to just say how items should be aligned in both axes removes the need to do margin or positioning shenanigans). But it was all very possible with basic flow layout

I worry that focusing on old layout techniques and hacks to get them to work, will propagate old layout techniques and hacks to get them to work.