@csstools/postcss-light-dark-function v1.0.3

PostCSS Light Dark Function

npm install @csstools/postcss-light-dark-function --save-dev

PostCSS Light Dark Function lets you use the light-dark color function in CSS, following the CSS Color 5 Specification.

.dark {
	color-scheme: dark;
}

.light {
	color-scheme: light;
}

.theme {
	color: light-dark(pink, magenta);
}

.prop {
	--theme-color: light-dark(cyan, deepskyblue);
}

/* becomes */

.dark {
	--csstools-color-scheme--dark: initial;
	color-scheme: dark;
}

.light {
	--csstools-color-scheme--dark:  ;
	color-scheme: light;
}

.theme {
	--csstools-light-dark-toggle--0: var(--csstools-color-scheme--dark) pink;
	color: var(--csstools-light-dark-toggle--0, magenta);
	color: light-dark(pink, magenta);
}

.prop {
	--csstools-light-dark-toggle--1: var(--csstools-color-scheme--dark) cyan;
	--theme-color: var(--csstools-light-dark-toggle--1, deepskyblue);
	& * {
	--csstools-light-dark-toggle--1: var(--csstools-color-scheme--dark) cyan;
	--theme-color: var(--csstools-light-dark-toggle--1, deepskyblue);
	}
}

@supports (color: light-dark(red, red)) {
.prop {
	--theme-color: light-dark(cyan, deepskyblue);
}
}

Usage

Add PostCSS Light Dark Function to your project:

npm install postcss @csstools/postcss-light-dark-function --save-dev

Use it as a PostCSS plugin:

const postcss = require('postcss');
const postcssLightDarkFunction = require('@csstools/postcss-light-dark-function');

postcss([
	postcssLightDarkFunction(/* pluginOptions */)
]).process(YOUR_CSS /*, processOptions */);

PostCSS Light Dark Function runs in all Node environments, with special instructions for:

• Node
• PostCSS CLI
• PostCSS Load Config
• Webpack
• Next.js
• Gulp
• Grunt

Options

preserve

The preserve option determines whether the original notation is preserved. By default, it is preserved.

postcssLightDarkFunction({ preserve: false })

.dark {
	color-scheme: dark;
}

.light {
	color-scheme: light;
}

.theme {
	color: light-dark(pink, magenta);
}

.prop {
	--theme-color: light-dark(cyan, deepskyblue);
}

/* becomes */

.dark {
	--csstools-color-scheme--dark: initial;
	color-scheme: dark;
}

.light {
	--csstools-color-scheme--dark:  ;
	color-scheme: light;
}

.theme {
	--csstools-light-dark-toggle--0: var(--csstools-color-scheme--dark) pink;
	color: var(--csstools-light-dark-toggle--0, magenta);
}

.prop {
	--csstools-light-dark-toggle--1: var(--csstools-color-scheme--dark) cyan;
	--theme-color: var(--csstools-light-dark-toggle--1, deepskyblue);
	& * {
	--csstools-light-dark-toggle--1: var(--csstools-color-scheme--dark) cyan;
	--theme-color: var(--csstools-light-dark-toggle--1, deepskyblue);
	}
}

enableProgressiveCustomProperties

The enableProgressiveCustomProperties option determines whether the original notation is wrapped with @supports when used in Custom Properties. By default, it is enabled.

!NOTE We only recommend disabling this when you set preserve to false or if you bring your own fix for Custom Properties.
See what the plugin does in its README.

postcssLightDarkFunction({ enableProgressiveCustomProperties: false })