CHANGELOG.md

Changes to PostCSS Progressive Custom Properties

Unreleased (patch)

• Update @webref/css to v8.7.1

5.1.1

June 28, 2026

• Fix support conditions for shorthands followed by longhands.

:root {
	background: var(--green);
	background: image(var(--green));
	background-size: 100px;
}

Now preserves the background-size longhand in the supports condition and becomes

:root {
	background: var(--green);
	background-size: 100px;
}

@supports (background-image: image(red)) {
	:root {
		background: image(var(--green));
		background-size: 100px;
	}
}

5.1.0

May 13, 2026

• Add support for image(red)

5.0.0

January 14, 2026

• Updated: Support for Node 20.19.0 or later (major).
• Removed: commonjs API. In supported Node versions require(esm) will work without needing to make code changes.

4.2.1

September 21, 2025

• Remove redundant match for contrast-color( <color> );

4.2.0

August 22, 2025

• Add support for color(display-p3-linear 0.3081 0.014 0.0567)
• Add support for color-mix(in display-p3-linear, red, blue)
• Add support for color-mix(red, blue)
• Add support for alpha(from red / 0.5)

4.1.0

May 27, 2025

• Add matching rules for variadic function arguments in color-mix()

4.0.1

April 19, 2025

• Drop the max keyword for contrast-color( <color> )

4.0.0

August 3, 2024

• Updated: Support for Node v18+ (major).

3.3.0

July 7, 2024

• Add matching rules for alt text in content

3.2.0

March 31, 2024

• Add matching rules for contrast-color

3.1.1

March 13, 2024

• Test for mixed component types in color values (e.g. lab(100 50% 50))
• Allow relative color syntax in rgba and hsla color notations.

3.1.0

February 19, 2024

• Add matching rules for light-dark

3.0.3

December 15, 2023

• Fix type definitions

3.0.2

October 9, 2023

• Add support for css nesting
• Improve grouping of @supports rules
• Reduce the size of the generated @supports rules for values that contain var()

3.0.1

September 18, 2023

• Improve performance

3.0.0

July 3, 2023

• Change license to MIT-0 (read more about this change in the blog post)

2.3.0

June 1, 2023

• Add support for regular properties whose values contain var()

.property-with-var--1 {
	color: rgba(87, 107, 149, var(--opacity));
	color: rgb(87 107 149 / var(--opacity));
}

/* becomes */
.property-with-var--1 {
	color: rgba(87, 107, 149, var(--opacity));
}

@supports (color: rgb(0 0 0 / 0)) and (top: var(--f)) {
	.property-with-var--1 {
		color: rgb(87 107 149 / var(--opacity));
	}
}

2.2.0

May 19, 2023

• Add relative color syntax support.
• Fix false positive matches for rgb and hsl modern function notations.

2.1.1

March 25, 2023

• Smaller @supports check for color-mix.

2.1.0

February 2, 2023

• Group support rules with the same params to reduce the output size.

2.0.1

January 28, 2023

• Improve types declaration in package.json

2.0.0

January 24, 2023

• Updated: Support for Node v14+ (major).

1.3.0 (March 7, 2022)

• Add matching rules for color-mix
• Fix matching rules for gradient functions
• Reduce matchers size

1.2.0 (February 15, 2022)

• More matching rules for double position gradients.

1.1.0 (February 12, 2022)

• No longer uses custom properties in @supports rules.
• Implement AST matching for values and units and generate minimal @supports for select features.

1.0.0 (February 6, 2022)

Initial release