[I generally don't use aritrary classes with Tailwind CSS][0].
But, they are powerful, and I do use them in some situations.
A few months ago, [I posted a screenshot of a timeline component][1] I've built for a client project.
Today, I needed to fix an issue with the first and last "paths" as they were stretching further than they should.
This is the class I added to fix the problem:
> mr-[calc(50%_-_calc(var(--path-width)_/_2))]
It adds an arbitrary amount of right margin, which is 50% of the container minus half of the path width, which is the `--path-width` variable.
This class uses the `calc` function as well as `var` to determine the correct margin to apply, whilst keeping the code adaptable in case the path width changes.
And, as this is a value that's only used in this component, there's no benefit to writing this in a stylesheet - making an arbitrary value was a good option.
