---
title: The power of arbitrary classes
date: 2024-07-15
permalink: daily/2024/07/15/the-power-of-arbitrary-classes
tags:
  - software-development
  - css
  - tailwind-css
cta: ~
snippet: |
  I don't often use them, but arbitrary classes in Tailwind can be powerful.
---

[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.

[0]: {{site.url}}/archive/2023/01/02/dont-use-arbitrary-values-in-tailwind-css
[1]: https://x.com/opdavies/status/1755332703308652730