tailwindcss-logical

A CSS Logical Properties and Values plugin for Tailwind CSS, compatible with Tailwind v3. For compatibility with Tailwind v2 and v1.2.0+, please use version v2.0.0 of this plugin.

Note: Tailwind CSS now officially supports some of the most commonly-used Logical Properties and Values in v3.3.0. We recommend trying the update to see if it is sufficient for your needs before using this plugin.

Demo

View the demo page for a visual walkthrough, or read on to get started.

Usage

Install tailwindcss-logical as a dependency of your project:

npm install tailwindcss-logical --save-dev

Register tailwindcss-logical in the plugins section of your Tailwind config file:

// tailwind.config.js
module.exports = {
  plugins: [
    require('tailwindcss-logical')
  ]
}

Before Tailwind v3 it was necessary to add the variants you needed for tailwindcss-logical to variants.logical in your Tailwind config file, but now this is no longer necessary.

What are CSS Logical Properties and Values?

In short, CSS Logical Properties and Values extend CSS for easier development when working with non-LTR (left-to-right) languages. For example, let's say you want to add padding before the start of a paragraph of text. For English, which is LTR, you would do this:

.lead-paragraph { padding-left: 1rem; }

However, for Farsi, which reads right-to-left, that would cause the padding to be at the end of the text rather than the beginning, so you would have to do something like this to cover both cases:

.lead-paragraph { padding-left: 1rem; }
html[dir="rtl"] .lead-paragraph { padding-left: 0; padding-right: 1rem; }

CSS Logical Properties and Values simplifies this by abstracting away the specific directions. The above example becomes this:

.lead-paragraph { padding-inline-start: 1rem; }

With one style, the padding is applied as intended for either language. For more about CSS Logical Properties and Values, see Building Multi-Directional Layouts by Ahmad El-Alfy.

What's Included

Flow-relative Values for float and clear

.float-start { float: inline-start; }
.float-end { float: inline-end; }
.clear-start { clear: inline-start; }
.clear-end { clear: inline-end; }

Flow-relative Values for text-align

.text-start { text-align: start; }
.text-end { text-align: end; }

Flow-relative Values for resize

.resize-block { resize: block; }
.resize-inline { resize: inline; }

Flow-relative Longhands for overscroll-behavior

.overscroll-b-auto { overscroll-behavior-block: auto; }
.overscroll-b-contain { overscroll-behavior-block: contain; }
.overscroll-b-none { overscroll-behavior-block: none; }
.overscroll-i-auto { overscroll-behavior-inline: auto; }
.overscroll-i-contain { overscroll-behavior-inline: contain; }
.overscroll-i-none { overscroll-behavior-inline: none; }

Logical Height and Logical Width

Utilities are generated for the block-size, inline-size, min-block-size, min-inline-size, max-block-size, and max-inline-size properties. These match the values in your height, width, min-height, min-width, max-height, and max-width config objects, respectively.

.bs-1 { block-size: 0.25rem; }
.is-1 { inline-size: 0.25rem; }
.min-bs-0 { min-block-size: 0; }
.min-is-0 { min-inline-size: 0; }
.max-bs-full { max-block-size: 100%; }
.max-is-full { max-inline-size: 100%; }

Flow-relative Margins

Utilities are generated for the margin-block-start, margin-block-end, margin-inline-start, and margin-inline-end properties, as well as for the shorthand properties margin-block and margin-inline. These match the values in your margin config object.

.mlb-1 { margin-block: 0.25rem; }
.mli-1 { margin-inline: 0.25rem; }
.mbs-1 { margin-block-start: 0.25rem; }
.mbe-1 { margin-block-end: 0.25rem; }
.mis-1 { margin-inline-start: 0.25rem; }
.mie-1 { margin-inline-end: 0.25rem; }

Flow-relative Padding

Utilities are generated for the padding-block-start, padding-block-end, padding-inline-start, and padding-inline-end properties, as well as for the shorthand properties padding-block and padding-end. These match the values in your padding config object.

.plb-1 { padding-block: 0.25rem; }
.pli-1 { padding-inline: 0.25rem; }
.pbs-1 { padding-block-start: 0.25rem; }
.pbe-1 { padding-block-end: 0.25rem; }
.pis-1 { padding-inline-start: 0.25rem; }
.pie-1 { padding-inline-end: 0.25rem; }

Flow-relative Space Between

Flow-relative utilities are generated for the Tailwind-specific Space Between. These match the values in your space config object. All of the usual positive and negative values plus .space-b-reverse and .space-i-reverse utilities are generated.

.space-b-1 > :not([hidden]) ~ :not([hidden]) {
  --tw-space-b-reverse: 0;
  margin-block-start: calc(0.25rem * calc(1 - var(--tw-space-b-reverse)));
  margin-block-end: calc(0.25rem * var(--tw-space-b-reverse))
}

.space-i-1 > :not([hidden]) ~ :not([hidden]) {
  --tw-space-i-reverse: 0;
  margin-inline-start: calc(0.25rem * calc(1 - var(--tw-space-i-reverse)));
  margin-inline-end: calc(0.25rem * var(--tw-space-i-reverse))
}

Flow-relative Offsets (top / right / bottom / left)

Utilities are generated for the inset-block-start, inset-block-end, inset-inline-start, and inset-inline-end properties, as well as for the shorthand properties inset-block and inset-inline. These match the values in your inset config object.

.inset-block-0 { inset-block: 0; }
.inset-inline-0 { inset-inline: 0; }
.block-start-0 { inset-block-start: 0; }
.block-end-0 { inset-block-end: 0; }
.inline-start-0 { inset-inline-start: 0; }
.inline-end-0 { inset-inline-end: 0; }

Flow-relative Border Widths

Utilities are generated for the border-block-width, border-inline-width, border-block-start-width, border-block-end-width, border-inline-start-width, and border-inline-end-width properties. These match the values in your borderWidth config object.

.border-lb-2 { border-block-width: 2px; }
.border-li-2 { border-inline-width: 2px; }
.border-bs-2 { border-block-start-width: 2px; }
.border-be-2 { border-block-end-width: 2px; }
.border-is-2 { border-inline-start-width: 2px; }
.border-ie-2 { border-inline-end-width: 2px; }

Flow-relative Border Colors

Utilities are generated for the border-block-color, border-inline-color, border-block-start-color, border-block-end-color, border-inline-start-color, and border-inline-end-color properties. These match the values in your borderColor config object.

.border-lb-black { border-block-color: #000; }
.border-li-black { border-inline-color: #000; }
.border-bs-black { border-block-start-color: #000; }
.border-be-black { border-block-end-color: #000; }
.border-is-black { border-inline-start-color: #000; }
.border-ie-black { border-inline-end-color: #000; }

Flow-relative Divide Width

Flow-relative utilities are generated for the Tailwind-specific Divide Width. These match the values in your divideWidth config object. All of the usual values plus .divide-b, .divide-i, .divide-b-reverse and .divide-i-reverse utilities are generated.

.divide-b-2 > :not([hidden]) ~ :not([hidden]) {
  --tw-divide-b-reverse: 0;
  border-block-start-width: calc(2px * calc(1 - var(--tw-divide-b-reverse)));
  border-block-end-width: calc(2px * var(--tw-divide-b-reverse))
}

.divide-i-2 > :not([hidden]) ~ :not([hidden]) {
  --tw-divide-i-reverse: 0;
  border-inline-start-width: calc(2px * calc(1 - var(--tw-divide-i-reverse)));
  border-inline-end-width: calc(2px * var(--tw-divide-i-reverse))
}

Flow-relative Corner Rounding (border-radius)

Utility classes are generated for the border-start-start-radius, border-start-end-radius, border-end-start-radius, and border-end-end-radius properties for rounding individual corners. There are also shorthand utilities for rounding a side of an element. These match the values in your borderRadius config object.

.rounded-bs-md {
  border-start-start-radius: 0.375rem;
  border-start-end-radius: 0.375rem;
}

.rounded-be-md {
  border-end-start-radius: 0.375rem;
  border-end-end-radius: 0.375rem;
}

.rounded-is-md {
  border-start-start-radius: 0.375rem;
  border-end-start-radius: 0.375rem;
}

.rounded-ie-md {
  border-start-end-radius: 0.375rem;
  border-end-end-radius: 0.375rem;
}

.rounded-ss-md { border-start-start-radius: 0.375rem; }
.rounded-se-md { border-start-end-radius: 0.375rem; }
.rounded-es-md { border-end-start-radius: 0.375rem; }
.rounded-ee-md { border-end-end-radius: 0.375rem; }

What's Not Included

While everything in the CSS Logical Properties and Values Level 1 specification has been evaluated and most features are supported, this plugin does not generate utilities for everything. If something does not have a non-logical equivalent in Tailwind's defaults, it is not supported.

• Logical Values for the caption-side property: Tailwind does not have caption-side utilities.
• Flow-relative Border Styles: Tailwind only has border-style utilities for all sides of an element at once.

As for other logical properties and values from outside of the main specification:

• Flow-relative Overflow properties overflow-block and overflow-inline: while Tailwind does support overflow, this plugin does not support overflow-block or overflow-inline yet, due to a lack of browser support and polyfills. As of December 2021, only Firefox supports them, and as far as I can tell there are no polyfills available. (Neither postcss-preset-env nor postcss-logical apply any transformations on these properties.)

If there are any notable omissions that you think should be supported, please file an issue and let me know.

Browser Compatibility

Browser support for CSS Logical Properties and Values has come a long way in 2021. Nearly all of the utilities provided with this plugin now have widespread support across major browsers: Edge, Firefox, Chrome, Safari, Safari for iOS, and Chrome for Android included. Some exceptions are flow-relative resize, flow-relative float, and flow-relative overscroll-behavior, and none of the logical properties and values are supported in Internet Explorer 11.

If some utilities don't seem to work correctly, be sure to check Can I use... to see if that property or value is supported by your browser. Relevant Can I use... links for each set of utilities are included in the demo page.

If better browser support is required, you can use PostCSS to improve compatibility. Here are two possible solutions:

1. postcss-preset-env set to stage: 2 or lower
2. postcss-logical followed by postcss-dir-pseudo-class

If you take your output styles from Tailwind and run them through either of the above, your logical properties and values will be converted to attribute selectors that any browser can understand.

/* Default */
.float-start { float: inline-start; }

/* With postcss-preset-env, or postcss-logical and postcss-dir-pseudo-class applied */
[dir="ltr"] .float-start { float: left; }
[dir="rtl"] .float-start { float: right; }

This process is used for this project's demo page, and for a look at how that is configured for PostCSS, check out the demo's postcss.config.js file.

Roadmap

At this point I consider this plugin feature complete, but I will continue to monitor official specifications, as well as Tailwind itself, and update this plugin accordingly when anything changes.

Contributing

If you would like to contribute, pull requests are totally welcome, though I recommend starting by filing an issue.

1. Fork the project
2. Check out a feature branch (e.g. git checkout -b feature-foo-bar)
3. Commit changes (e.g. git commit -am 'Add foo bar')
4. Push the branch (e.g. git push origin feature-foo-bar)
5. Create a new Pull Request

Contact

Steve Cochrane ([email protected])