# [postcss][postcss]-merge-rules > Merge CSS rules with PostCSS. ## Install With [npm](https://npmjs.org/package/postcss-merge-rules) do: ``` npm install postcss-merge-rules --save ``` ## Examples This module will attempt to merge *adjacent* CSS rules: ### By declarations #### Input ```css a { color: blue; font-weight: bold } p { color: blue; font-weight: bold } ``` #### Output ```css a,p { color: blue; font-weight: bold } ``` ### By selectors #### Input ```css a { color: blue } a { font-weight: bold } ``` #### Output ```css a { color: blue; font-weight: bold } ``` ### By partial declarations #### Input ```css a { font-weight: bold } p { color: blue; font-weight: bold } ``` #### Output ```css a,p { font-weight: bold } p { color: blue } ``` ## Usage See the [PostCSS documentation](https://github.com/postcss/postcss#usage) for examples for your environment. ## Contributors See [CONTRIBUTORS.md](https://github.com/cssnano/cssnano/blob/master/CONTRIBUTORS.md). ## License MIT © [Ben Briggs](http://beneb.info) [postcss]: https://github.com/postcss/postcss