# PostCSS Stepped Value Functions [PostCSS Logo][postcss] [npm version][npm-url] [CSS Standard Status][css-url] [Build Status][cli-url] [Discord][discord] [PostCSS Stepped Value Functions] lets you use `round`, `rem` and `mod` stepped value functions, following the [CSS Values 4]. ```pcss .test-functions { padding: 8px mod(18px, 5px) 1px calc(rem(15px, 6px) + 50%); transform: rotate(mod(-140deg, -90deg)); top: round(15px, 4px); right: round(nearest, 15px, 4px); bottom: round(up, 15px, 7px); left: round(down, 15px, 4px); width: round(to-zero, 15px, 4px); } /* becomes */ .test-functions { padding: 8px 3px 1px calc(3px + 50%); transform: rotate(-50deg); top: 16px; right: 16px; bottom: 21px; left: 12px; width: 12px; } ``` ## Usage Add [PostCSS Stepped Value Functions] to your project: ```bash npm install postcss @csstools/postcss-stepped-value-functions --save-dev ``` Use it as a [PostCSS] plugin: ```js const postcss = require('postcss'); const postcssSteppedValueFunctions = require('@csstools/postcss-stepped-value-functions'); postcss([ postcssSteppedValueFunctions(/* pluginOptions */) ]).process(YOUR_CSS /*, processOptions */); ``` [PostCSS Stepped Value Functions] runs in all Node environments, with special instructions for: | [Node](INSTALL.md#node) | [PostCSS CLI](INSTALL.md#postcss-cli) | [Webpack](INSTALL.md#webpack) | [Create React App](INSTALL.md#create-react-app) | [Gulp](INSTALL.md#gulp) | [Grunt](INSTALL.md#grunt) | | --- | --- | --- | --- | --- | --- | ## ⚠️ About custom properties Given the dynamic nature of custom properties it's impossible to know what the variable value is which means the plugin can't compute a final value for the stylesheet. Because of that, any usage that contains a `var` is skipped. ## Options ### preserve The `preserve` option determines whether the original notation is preserved. By default, it is not preserved. ```js postcssSteppedValueFunctions({ preserve: true }) ``` ```pcss .test-functions { padding: 8px mod(18px, 5px) 1px calc(rem(15px, 6px) + 50%); transform: rotate(mod(-140deg, -90deg)); top: round(15px, 4px); right: round(nearest, 15px, 4px); bottom: round(up, 15px, 7px); left: round(down, 15px, 4px); width: round(to-zero, 15px, 4px); } /* becomes */ .test-functions { padding: 8px 3px 1px calc(3px + 50%); padding: 8px mod(18px, 5px) 1px calc(rem(15px, 6px) + 50%); transform: rotate(-50deg); transform: rotate(mod(-140deg, -90deg)); top: 16px; top: round(15px, 4px); right: 16px; right: round(nearest, 15px, 4px); bottom: 21px; bottom: round(up, 15px, 7px); left: 12px; left: round(down, 15px, 4px); width: 12px; width: round(to-zero, 15px, 4px); } ``` ### onInvalid `onInvalid` option allows you to assign the `warn` value so you can get warnings when the usage of the functions is wrong. ```js postcssSteppedValueFunctions({ onInvalid: 'warn' }) ``` ```pcss .invalid { font-size: mod(18px, 5rem); } ``` Will produce on the terminal: ```bash [postcss-stepped-value-functions]: Failed to transform mod(18px, 5rem) as the units don't match ``` [cli-url]: https://github.com/csstools/postcss-plugins/actions/workflows/test.yml?query=workflow/test [css-url]: https://cssdb.org/#stepped-value-functions [discord]: https://discord.gg/bUadyRwkJS [npm-url]: https://www.npmjs.com/package/@csstools/postcss-stepped-value-functions [Gulp PostCSS]: https://github.com/postcss/gulp-postcss [Grunt PostCSS]: https://github.com/nDmitry/grunt-postcss [PostCSS]: https://github.com/postcss/postcss [PostCSS Loader]: https://github.com/postcss/postcss-loader [PostCSS Stepped Value Functions]: https://github.com/csstools/postcss-plugins/tree/main/plugins/postcss-stepped-value-functions [CSS Values 4]: https://www.w3.org/TR/css-values-4/#round-func