I like how he kept "tabs" (and display it as 9 spaces) to make it as ugly as possible for the bad example, then proceed to use 4 spaces for the other examples.
I suspect this is substacks default styling. It actually doesn’t set the tab-size which defaults to 8. However there seems to be some funky font-rendering going on so it adds an extra half (or maybe three-quarters) of a space per tab-character.
You can see this your self if you edit the markup in your browser’s inspector and add `contenteditable` attribute to the surrounding <pre>, then navigate down a line... it will jump forward just by slightly less then a column per indent level.
I'm well aware of it. But I don't think I have ever seen an editor/website which would display it as 9 spaces. Github for example default to 4 spaces width.
Yes, this is very weird. But Go Playground[1] has always been using 8 spaces per tab for some reason. I always found that very jarring, particularly where almost every other editor or documentation has settled on 4 spaces per tab.
You can see this your self if you edit the markup in your browser’s inspector and add `contenteditable` attribute to the surrounding <pre>, then navigate down a line... it will jump forward just by slightly less then a column per indent level.