PostCSS Logical Properties lets you use nearly 60 new logical properties and a half dozen flow-relative values in CSS.

.banner {
  color: #222222;
  inset: logical 0 5px 10px;
  padding-inline: 20px 40px;
  resize: block;
}

/* used alongside postcss-nesting, postcss-dir-pseudo-class */

.banner {
  color: #222222;
  top: 0; left: 5px; bottom: 10px; right: 5px;
}

[dir="ltr"] .banner {
  padding-left: 20px; padding-right: 40px;
}

[dir="rtl"] .banner {
  padding-right: 20px; padding-left: 40px;
}

.banner {
  resize: vertical;
}

These shorthand properties set values for physical properties by default. Specifying the logical keyboard at the beginning of the property value will transform the flow-relative values afterward into both physical LTR and RTL properties:

• border, border-block, border-block-start, border-block-end, border-inline, border-inline-start, border-inline-end, border-start, border-end, border-color, border-block-color, border-block-start-color, border-block-end-color, border-inline-color, border-inline-start-color, border-inline-end-color, border-start-color, border-end-color, border-style, border-block-style, border-block-start-style, border-block-end-style, border-inline-style, border-inline-start-style, border-inline-end-style, border-start-style, border-end-style, border-width, border-block-width, border-block-start-width, border-block-end-width, border-inline-width, border-inline-start-width, border-inline-end-width, border-start-width, border-end-width

• inset, inset-block, inset-block-start, inset-block-end, inset-inline, inset-inline-start, inset-inline-end, inset-start, inset-end

• margin, margin-block, margin-block-start, margin-block-end, margin-inline, margin-inline-start, margin-inline-end, margin-start, margin-end

• padding, padding-block, padding-block-start, padding-block-end, padding-inline, padding-inline-start, padding-inline-end, padding-start, padding-end

• block-size, inline-size

• clear: inline-start, clear: inline-end, float: inline-start, float: inline-end, text-align: start, text-align: end

PostCSS Logical Properties changes the selector weight of flow-relative declarations and requires at least one [dir] attribute in your HTML. If you don’t have any [dir] attributes, consider using the following JavaScript:

// force at least one dir attribute (this can run at any time)
document.documentElement.dir=document.documentElement.dir||'ltr';

Add PostCSS Logical Properties to your build tool:

npm install postcss-logical --save-dev

Use PostCSS Logical Properties to process your CSS:

require('postcss-logical').process(YOUR_CSS);

Add PostCSS to your build tool:

npm install postcss --save-dev

Use PostCSS Logical Properties as a plugin:

postcss([
  require('postcss-logical')()
]).process(YOUR_CSS);

Add Gulp PostCSS to your build tool:

npm install gulp-postcss --save-dev

Use PostCSS Logical Properties in your Gulpfile:

var postcss = require('gulp-postcss');

gulp.task('css', function () {
  return gulp.src('./src/*.css').pipe(
    postcss([
      require('postcss-logical')()
    ])
  ).pipe(
    gulp.dest('.')
  );
});

Add Grunt PostCSS to your build tool:

npm install grunt-postcss --save-dev

Use PostCSS Logical Properties in your Gruntfile:

grunt.loadNpmTasks('grunt-postcss');

grunt.initConfig({
  postcss: {
    options: {
      use: [
        require('postcss-logical')()
      ]
    },
    dist: {
      src: '*.css'
    }
  }
});