From 7565dcec1674ce4c357986c31569d238a4e4d92e Mon Sep 17 00:00:00 2001 From: Tobias Wittwer Date: Tue, 25 Feb 2025 13:19:48 +0100 Subject: [PATCH] Add constraint for initial value in @property rule Adds the contraint of computationally independence for the initial value of @property rules. Spec-Reference: https://www.w3.org/TR/css-properties-values-api-1/#initial-value-descriptor --- files/en-us/web/css/@property/index.md | 3 +++ 1 file changed, 3 insertions(+) diff --git a/files/en-us/web/css/@property/index.md b/files/en-us/web/css/@property/index.md index 669690ac2d80ad9..a8d3f453fef7201 100644 --- a/files/en-us/web/css/@property/index.md +++ b/files/en-us/web/css/@property/index.md @@ -42,6 +42,9 @@ The following conditions must be met for the `@property` rule to be valid: If either is missing, the entire `@property` rule is invalid and ignored. - The {{cssxref("@property/initial-value","initial-value")}} descriptor is optional if the value of the `syntax` descriptor is the universal syntax definition (that is, `syntax: "*"`). If the `initial-value` descriptor is required but omitted, the entire `@property` rule is invalid and ignored. +- The {{cssxref("@property/initial-value","initial-value")}} descriptor has to be a [computationally independent value](https://www.w3.org/TR/css-properties-values-api-1/#computationally-independent) + if the value of the `syntax` descriptor is not the universal syntax definition (that is, `syntax: "*"`). + This excludes relative units like `rem`. - Unknown descriptors are invalid and ignored, but do not invalidate the `@property` rule. ## Formal syntax