Hacking CSS writing mode

The writing-mode CSS property sets horizontal and vertical text direction. While meant for multilingual purposes, it can be exploited for design.
The basics
The writing-mode CSS property sets the direction of content, both horizontally and vertically.
CSS
The values are:

horizontal-tb

Content flows horizontally from left to right, vertically from top to bottom. The default value.

vertical-rl

Content flows vertically from top to bottom, horizontally from right to left.

vertical-lr

Content flows vertically from top to bottom, horizontally from left to right.

Example 1
A simple, minimalist example to start.
Post
Modernism
The HTML
Two divs.
HTML
The CSS
In the v-block div, the writing-mode property has a value of vertical-rl.
CSS
Example 2
Another minimalist example.
Post
Modernist
Thought
The HTML
Again, two divs, but note how the text flows in v-block from right to left. The CSS is the same as above.
HTML
Example 3
And now we add transform with a rotate value.
A Guide to
Post
Modernist
Thought
The HTML
We're using a basic flexbox container to hold things together.
HTML
The CSS
The transform property in w-block-2 has a rotate value, along with big padding.
CSS
Writing-mode works with Edge 12+, Chrome 48+, Firefox 41+, Safari 11+, iOS Safari 11+, Chrome for Android 70+, Android browser 67+, Firefox for Android 63 and Opera 35+.