v1.28.2

Fixes

• Fix duplicate prefixed properties in transition-property – #850 (thanks @RobinMalfait and @LeoniePhiline!)
• Fix mapping original name from source maps – 78f2fc4
• Bump browser compat data – 4159bc5
• Ensure consistent order of custom properties when all property is set – d4eec35

v1.28.0

Added

• Add option to avoid hashing @container names in CSS Modules by @kdy1 in #835
• Improve error message of input:placeholder by @kdy1 in #813
• Add an error for the deprecated @value at-rule of CSS Modules by @kdy1 in #842

Fixed

• Don't panic when passing system-color to color-mix by @inottn in #819
• Dependency updates by @kornelski in #814
• Fix order of fallback width, height, and other size related properties – 22a8b6f
• Fix stack overflow parsing calc expression – e3c8e12
• Fix crash when parsing an invalid calc expression – 378955e
• Skip clamp function reduction when the comparison between preferred and max value is unknown – ddc9ce8
• Update browser compatibility data – f6b033f
• docs: Update help command docs by @DylanPiercey in #812
• docs: fix link to visitor type definitions by @mayank99 in #823

v1.27.0

Added

• Add [content-hash] css module pattern by @rubberpants in #802. This includes a hash of the file contents rather than the file path (as [hash] works), which can be used to support multiple versions of the same library simultaneously without conflicts.
• Improve error message for pseudo elements followed by selectors by @kdy1 in #797
• Implement pure mode lints for CSS Modules by @kdy1 in #796. This option enforces the use of a class or id selector in each rule.

Fixed

• Fix box-shadow combination of oklch and currentColor by @hi-ogawa in #801
• Add missing browserslist import in docs.md by @cpeaustriajc in #798
• Update broken selectors link in homepage by @20jasper in #750
• Make CLI example work with Windows by @tim-we in #726
• Update copyright year on main page by @log101 in #790
• Update browser compat data - 54390b4

v1.26.0

Added

• Add support for named timeline ranges in @keyframes by @grimsteel in #787
• Implement animation-range properties – 39964f1
• Add a lint for unsupported CSS Module selector by @kdy1 in #784
• add wasm file to package exports by @elevatebart in #755
• Add support for arm64 Windows – 0bcd896

Fixed

• Fix codegen of :is(input:checked) by @kdy1 in #783
• Bump browserslist-rs 0.16.0 by @chenjiahan in #772
• update compat data – dcbb997

v1.25.1

Fixes a property ordering bug when using the all shorthand.

v1.25.0

This release adds more granular options for CSS modules, implements some new CSS properties, and fixes bugs.

Added

• Add granular options to control which identifiers are scoped in CSS modules. You can turn off scoping for grid, animation, and custom_idents. This may be useful when migrating from other tools. See docs. Thanks @timneutkens! 83839a9
• Optimize the all shorthand property to reset other properties except direction and unicode-bidi. d7aeff3
• Implement animation-timeline property and add support for it in the animation shorthand f4408c7

Fixed

• Prevent simplifying translate: none and scale: none which are distinct from translate: 0 and scale: 1. Thanks @RobinMalfait! a4cc024
• Fix crash on box-shadow with currentColor keyword. Thanks @magic-akari! 06ba62f
• Fix minifier removing zero channels in color() function to follow spec change 445def9
• Fix CSS module scoping with variables in animation shorthand fb4b334
• Update browser compatibility data ec9da43

v1.24.1

• Disabled CSS transform optimizations using matrix(), which could break transitions and animations. – #694
• Merge @supports declarations with the same property (minus vendor prefix) and value – 6bd2761

v1.24.0

This release adds support the the light-dark() color function, parses CSS system colors, deduplicates custom properties during minification, merges duplicates @keyframes rules, and fixes some bugs.

light-dark()

The light-dark() function allows you to specify a light mode and dark mode color in a single declaration, without needing to write a separate media query rule. In addition, it uses the color-scheme property to control which theme to use, which allows you to set it programmatically. The color-scheme property also inherits so themes can be nested and the nearest ancestor color scheme applies.

Lightning CSS converts the light-dark() function to use CSS variable fallback when your browser targets don't support it natively. For this to work, you must set the color-scheme property on an ancestor element. The following example shows how you can support both operating system and programmatic overrides for the color scheme.

html {
  color-scheme: light dark;
}

html[data-theme=light] {
  color-scheme: light;
}

html[data-theme=dark] {
  color-scheme: dark;
}

button {
  background: light-dark(#aaa, #444);
}

compiles to:

html {
  --lightningcss-light: initial;
  --lightningcss-dark: ;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  html {
    --lightningcss-light: ;
    --lightningcss-dark: initial;
  }
}

html[data-theme="light"] {
  --lightningcss-light: initial;
  --lightningcss-dark: ;
  color-scheme: light;
}

html[data-theme="dark"] {
  --lightningcss-light: ;
  --lightningcss-dark: initial;
  color-scheme: dark;
}

button {
  background: var(--lightningcss-light, #aaa) var(--lightningcss-dark, #444);
}

Check it out in the playground.

CSS system colors

CSS system colors are now supported during parsing, meaning they can be safely deduplicated when merging rules.

.a {
  background: Highlight;
}

.a {
  background: ButtonText;
}

compiles to:

.a{background:buttontext}

Custom property deduplication

CSS custom properties are now deduplicated when merging rules. The last property value always wins.

.a {
  --foo: red;
}

.a {
  --foo: green;
}

minifies to:

.a{--foo:green}

@keyframes deduplication

@keyframes rules are also now deduplicated during minification. The last rule of the same name wins.

@keyframes a {
  from { opacity: 0 }
  to { opacity: 1 }
}

@keyframes a {
  from { color: red }
  to { color: blue }
}

compiles to:

@keyframes a{0%{color:red}to{color:#00f}}

Other bug fixes

• Bump browserslist-rs and browser compat data
• Don't output duplicate properties when incompatible with targets
• Parse a TokenList instead of only a single Token in @property rules

v1.23.0

This release improves minification for @layer and @property rules, enables relative colors to be compiled in more situations, adds new functionality for custom visitor plugins, and fixes some bugs.

Downlevel relative colors with unknown alpha

Lightning CSS can now down level relative colors where the alpha value is unknown (e.g. a variable). For example:

.foo {
  color: hsl(from yellow h s l / var(--alpha));
}

becomes:

.foo {
  color: hsla(60, 100%, 50%, var(--alpha));
}

Optimized @layer rules

@layer rules with the same name are now merged together and ordered following their original declared order. For example:

@layer a, b;

@layer b {
  .foo { color: red }
}

@layer a {
  .foo { background: yellow }
}

@layer b {
  .bar { color: red }
}

becomes:

@layer a {
  .foo { background: yellow }
}

@layer b {
  .foo, .bar { color: red }
}

Deduped @property rules

@property rules are now deduplicated when they define the same property name. The last rule wins.

@property --property-name {
  syntax: '<color>';
  inherits: false;
  initial-value: yellow;
}
.foo {
  color: var(--property-name)
}
@property --property-name {
  syntax: '<color>';
  inherits: true;
  initial-value: blue;
}

compiles to:

@property --property-name{
  syntax: "<color>";
  inherits: true;
  initial-value: #00f
}

.foo {
  color: var(--property-name)
}

StyleSheet visitor function

The JS visitor API now supports StyleSheet and StyleSheetExit visitors, allowing you to visit the entire stylesheet at once. This enables things like rule sorting or appending/prepending rules.

let res = transform({
  filename: 'test.css',
  minify: true,
  code: Buffer.from(`
    .foo {
      width: 32px;
    }

    .bar {
      width: 80px;
    }
  `),
  visitor: {
    StyleSheetExit(stylesheet) {
      stylesheet.rules.sort((a, b) => a.value.selectors[0][0].name.localeCompare(b.value.selectors[0][0].name));
      return stylesheet;
    }
  }
});

assert.equal(res.code.toString(), '.bar{width:80px}.foo{width:32px}');

Keep in mind that visiting the entire stylesheet can be expensive, due to needing to serialize and deserialize the entire AST to send between Rust and JavaScript. Keep visitors as granular as you can to avoid this.

Other bug fixes

• Fixed serializing grid-auto-flow in custom visitors
• Fixed compatibility data for -webkit-fill-available and -moz-available size values
• Added support for CommonJS in WASM package
• Allowed whitespace or nothing in initial-value of @property rules
• Fixed AST TypeScript types to have correct types for duplicated names

v1.22.1

• Init Wasm module only once in browsers – #615
• Update compat data – e255210
• Fix empty :is() when compiling nesting – b4bbe47