---
title: "Day 105: defining multiple syntax components"
url: https://daily.dev/posts/day-105-defining-multiple-syntax-components-rwnsjlrzm
source_url: https://www.matuzo.at/blog/2023/100daysof-day105
type: article
source: "Manuel Matuzović"
published: 2026-06-22T14:42:11.576Z
updated: 2026-06-22T14:43:51.288Z
tags: ["css"]
reading_time: 2
upvotes: 0
comments: 0
language: en
---

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# Day 105: defining multiple syntax components

**[Manuel Matuzović](https://daily.dev/sources/matuzo)** · 2 min read · 0 upvotes · 0 comments

## Summary

Covers how to define multiple syntax component types in a CSS @property at-rule using the '|' combinator. When a custom property is used with line-height (which accepts both numbers and lengths), restricting the syntax to a single type breaks transitions. By combining types like '<number> | <length-percentage>' in the syntax descriptor, the custom property accepts both value types while still enabling CSS transitions.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://www.matuzo.at/blog/2023/100daysof-day105>

---

Tags: [#css](https://daily.dev/tags/css)

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