I shall never begin to grasp why Grid was not a top priority and feature in CSS 1.0.
Two+ decades spent on kludges to have things line up in columns.
Two+ decades spent on kludges to have things line up in columns.
That's why laying things out vertically with CSS is often more challenging than laying things out horizontally. The assumption was that content starts at the top and flows downwards on an infinite canvas until it is finished, with the length of the document defined by the content. Contrast that with the width, where it has a finite size defined by the viewport and is wrapped.
This processing model makes perfect sense for documents, less so for application interfaces.
But please! CSS was a web technology from the start. I routinely committed the deadly sin of table layouts from the mid nineties all the way up into the new millenium, because that was the only way to do it. It is utterly beyond me how CSS - glib explanations or not - could blithely ignore this very real need all through 1.0, 2.0, and well into 3.0.
But I must say, Grid was almost worth the twenty years wait, and it does bring on a sweet nostalgic rush once again having to shake a fist at various MS browsers.
Sure, of course it was. But the web was almost entirely a collection of documents back then.
By some felicitous fluke I still have the very first html I ever coded, anno 1995, complete with background sound and animated gif - but cut me a bit of slack: It was purely a personal excercise. The thing was done purely from what I'd learned studying source of available websites. The point being: My God, it's full of tables. They were a real thing by that time.
Applications are not based off documents but rather the raw data (which the machine natively understands).
The transition of web from documents to a dumb platform for application software delivery is why the web is no longer the web. It is just application delivery infrastructure now. Each application lives in a walled garden and is no longer a "web" at all.
https://web.archive.org/web/19961022174810/http://www.altavi...
I learned the fundamentals of graphic design through print design, as that is a medium that designers have worked with for much longer than the computer screen. A lot of designers approach print design by starting with a grid that describes how their content will be laid out, and proceed from there. Of course, you can find exceptions to this (although in many cases they will be an example of a designer breaking the rules because they know them so well), but most design students will be familiar with that approach.
"Grid Systems in Graphic Design" (1981) is one of the reference texts on this subject, if you're interested in getting deeper.
The other commenters say, in reply to your question, that it was just for formatting HTML, and for web documents rather than applications. That is just completely missing the point - print documents are documents too, not applications. The main argument that the web is so different from print because the canvas is infinite doesn't make much sense either - even if the canvas is conceptually infinite, it still renders on a finite surface (your screen), and one can design modular grid systems that easily accommodate that (as well as the other related concerns, like the user not having the right font installed, or different pixel densities/aspect ratios, etc.).
In the end, the best explanation seems to be that the CSS spec was never led by actual designers who could envision the sort of problems that one would face when designing documents for the web. The CSS spec committee is full of very hard working, smart people, but they have the concerns of engineers first - browser compatibility, rendering complexity, etc. - rather than designers.
The fact that the "holy grail of web design"[0] is a thing is absolutely mind blowing to me. This is the kind of design any first semester design student would execute, and any styling language that does not let you implement it in 10 lines is a styling language resolutely not designed by (or for) designers.