Release 1.1.0

CHANGELOG.md

@@ -1,3 +1,22 @@
+# 1.1.0
+
+Released on Saturday, September 5 2026
+
+- Improved evaluation of comma-separated media queries (#230)
+- Fixed wrong media feature used for scripting (#233)
+- Fixed wrong rientation and scan evaluation (#232)
+- Fixed `not <known media type>` is always false (#231)
+- Fixed `calc()` computations in AoT-compiled applications (#236) @sebastienros
+- Fixed usage of `calc()` with unitless scaling (multiplication / division)
+- Fixed case-sensitive matching of `and` / `or` in `@supports` and `from` / `to` in `@keyframes` (#240) @meziantou
+- Fixed operator associativity and result units in `calc()` (#239) @meziantou
+- Fixed unquoted and invalid `url()` handling (#238) @meziantou
+- Fixed handling of invalid keyframe selectors
+- Fixed stackoverflow due to cyclic CSS variables (#241)
+- Added optional CSSOM compliant color seralization (#229) @lahma
+- Added user-preference media features to the render device (#235) @lahma
+- Added media query list evaluation using `IRenderDevice` (#228) @lahma
+
 # 1.0.2
 
 Released on Friday, August 21 2026.

CONTRIBUTORS.md

@@ -26,6 +26,7 @@ AngleSharp.Css contains code written by (in order of first pull request / commit
 * [MaceWindu](https://github.com/MaceWindu)
 * [Serhan Apaydın](https://github.com/monoblaine)
 * [scasteran](https://github.com/scasteran-jw)
+* [Sébastien Ros](https://github.com/sebastienros)
 
 Without these awesome people AngleSharp.Css could not exist. Thanks to everyone for your contributions! :beers:
 

README.md

@@ -41,6 +41,37 @@ var config = Configuration.Default
 
 If no specific `IRenderDevice` (e.g., via creating an `DefaultRenderDevice` object) instance is created a default implementation will be set.
 
+The render device also carries the *user preferences* of the Media Queries Level 5 (and Level 4) user-preference features. `DefaultRenderDevice` implements `IRenderDevicePreferences` for that, and any custom `IRenderDevice` can implement it as well. The dictionary is keyed by the media feature name and holds the keyword that the feature should answer with:
+
+```cs
+var config = Configuration.Default
+    .WithCss()
+    .WithRenderDevice(new DefaultRenderDevice
+    {
+        Preferences = new Dictionary<String, String>
+        {
+            { "prefers-color-scheme", "dark" },
+            { "prefers-reduced-motion", "reduce" },
+        },
+    });
+```
+
+With this device `@media (prefers-color-scheme: dark)` applies in the cascade and `window.MatchMedia("(prefers-color-scheme: dark)").IsMatched` is `true`. A key that is not set leaves its media feature unknown, i.e., a query using it never matches. The keys a browser would set are:
+
+| Key | Keywords |
+| --- | --- |
+| `prefers-color-scheme` | `light`, `dark` |
+| `prefers-reduced-motion` | `no-preference`, `reduce` |
+| `prefers-reduced-transparency` | `no-preference`, `reduce` |
+| `prefers-contrast` | `no-preference`, `more`, `less`, `custom` |
+| `prefers-reduced-data` | `no-preference`, `reduce` |
+| `forced-colors` | `none`, `active` |
+| `hover`, `any-hover` | `none`, `hover` |
+| `pointer`, `any-pointer` | `none`, `coarse`, `fine` |
+| `display-mode` | `fullscreen`, `standalone`, `minimal-ui`, `browser` |
+
+The value is compared to the queried keyword case insensitively, so a keyword that is newer than this library works as well. Used without a value, e.g., `@media (prefers-reduced-motion)`, the feature evaluates in a boolean context, where `no-preference` (and `none` for `forced-colors`, `hover`, `any-hover`, `pointer` and `any-pointer`) is `false`. Without a preference `hover` and `pointer` keep answering as they did before, i.e., as a device with no input mechanism.
+
 Going a bit further it is possible to `Render` the current document. This render tree information can then be used to retrieve or other information, e.g.,
 
 ```cs

docs/general/02-Values.md

@@ -62,3 +62,32 @@ Console.WriteLine($"Computed font-size: {computedFontSize}");
 - Shorthand values (e.g., `margin`, `background`) are decomposed internally to longhands.
 - Variables (`var(--x)`) may defer full resolution until cascade context is available.
 - Comparing raw source strings is often misleading; compare parsed or computed values instead.
+
+## Custom Properties At Computed-Value Time
+
+Custom properties are resolved only during style computation, for each element before
+they are inherited. `GetDeclarations`, `ComputeExplicitStyle`, `ComputeCascadedStyle`,
+and render-tree `SpecifiedStyle` retain the original variable expressions. Computed
+results are separate declarations and do not rewrite stylesheet or inline values.
+
+During computation, an inherited
+alias keeps the parent's resolved value; changing its dependencies on a child does not
+resolve that alias again. A declaration explicitly matching both elements is resolved
+locally on each element.
+
+Following [CSS Variables dependency-cycle rules](https://drafts.csswg.org/css-variables-1/#cycles),
+every property in a cycle becomes guaranteed-invalid, including cycles through unused
+fallbacks. A consuming `var(--name, fallback)` can recover from an invalid or missing
+custom property. Without a usable fallback, the consuming declaration uses its inherited
+or initial value, not an earlier declaration from the cascade. A valid custom-property
+value that does not match the consumer's grammar does not trigger the `var()` fallback.
+
+Dependency analysis and fallback substitution are iterative, including deeply nested
+fallbacks. The public parser still represents nested `var()` fallbacks as `CssVarValue`
+objects, and direct `CssReferenceValue.Compute` calls honor the supplied `References`
+array, including subsequent changes to its entries.
+
+Expanded values during style computation are limited to 1,048,576 UTF-16 code units (including token
+separators) to bound exponential substitution; an expansion exceeding this limit is
+invalid at computed-value time. Property-specific parsing, unit conversion, and layout
+support still determine which resolved values can be used by a consuming property.

docs/general/05-Extensibility.md

@@ -20,6 +20,8 @@ AngleSharp.Css is designed to be composed through services in the AngleSharp con
 : Add pseudo-element behavior.
 - `IRenderDevice`
 : Provide device characteristics for style computation.
+- `IRenderDevicePreferences`
+: Provide the user preferences answering the user-preference media features.
 
 ## Override The Default Stylesheet
 
@@ -56,6 +58,37 @@ var config = Configuration.Default
     .WithRenderDevice(renderDevice);
 ```
 
+## Provide The User Preferences
+
+Beside the dimensions a render device carries the user preferences, which answer the user-preference media features. `DefaultRenderDevice` implements `IRenderDevicePreferences` for that; a custom `IRenderDevice` can implement it as well and is picked up the same way.
+
+```cs
+var renderDevice = new DefaultRenderDevice
+{
+    Preferences = new Dictionary<String, String>
+    {
+        { "prefers-color-scheme", "dark" },
+        { "prefers-reduced-motion", "reduce" },
+    },
+};
+```
+
+The dictionary is keyed by the media feature name and holds the keyword the feature answers with. A key that is not set leaves its media feature unknown, i.e., a query using it never matches.
+
+| Key | Keywords |
+| --- | --- |
+| `prefers-color-scheme` | `light`, `dark` |
+| `prefers-reduced-motion` | `no-preference`, `reduce` |
+| `prefers-reduced-transparency` | `no-preference`, `reduce` |
+| `prefers-contrast` | `no-preference`, `more`, `less`, `custom` |
+| `prefers-reduced-data` | `no-preference`, `reduce` |
+| `forced-colors` | `none`, `active` |
+| `hover`, `any-hover` | `none`, `hover` |
+| `pointer`, `any-pointer` | `none`, `coarse`, `fine` |
+| `display-mode` | `fullscreen`, `standalone`, `minimal-ui`, `browser` |
+
+The value is compared to the queried keyword case insensitively, so a keyword that is newer than this library works as well. Used without a value, e.g., `@media (prefers-reduced-motion)`, the feature evaluates in a boolean context, where `no-preference` (and `none` for `forced-colors`, `hover`, `any-hover`, `pointer` and `any-pointer`) is `false`. Without a preference `hover` and `pointer` keep answering as they did before, i.e., as a device with no input mechanism.
+
 ## Composition Pattern
 
 Start from the default registrations and replace only what you need:

docs/tutorials/04-Questions.md

@@ -6,24 +6,36 @@ section: "AngleSharp.Css"
 
 ## How to change the color output?
 
-By default, AngleSharp.Css uses `rgba()` for the serialization of `Color`. To change this you can set
+By default, AngleSharp.Css uses `rgba()` for the serialization of `CssColorValue`. To change this you can set
 
 ```cs
-Color.UseHex = true;
+CssColorValue.UseHex = true;
 ```
 
 which will automatically use hex for all non-transparent colors. All other colors would still be represented via the `rgba()` function.
 
 So you'd get:
 
 ```cs
-Color.UseHex = true;
-var color1 = new Color(65, 12, 48);
+CssColorValue.UseHex = true;
+var color1 = new CssColorValue(65, 12, 48);
 // color1.CssText = #410C30
-var color2 = new Color(65, 12, 48, 10);
+var color2 = new CssColorValue(65, 12, 48, 10);
 // color2.CssText = rgba(65, 12, 48, 0.04)
 ```
 
+Alternatively, you can follow the serialization rules from the CSSOM specification, which omit the alpha channel of an opaque color:
+
+```cs
+CssColorValue.UseSpecSerialization = true;
+var color1 = new CssColorValue(65, 12, 48);
+// color1.CssText = rgb(65, 12, 48)
+var color2 = new CssColorValue(65, 12, 48, 10);
+// color2.CssText = rgba(65, 12, 48, 0.04)
+```
+
+Both switches are global and `UseHex` wins if both are active.
+
 ## Why is my linked stylesheet not loaded?
 
 Most commonly, resource loading is not enabled. For external stylesheets, configure a requester and enable resource loading.

src/AngleSharp.Css.Docs/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@anglesharp/css",
-  "version": "1.0.2",
+  "version": "1.1.0",
   "preview": true,
   "description": "The doclet for the AngleSharp.Css documentation.",
   "keywords": [

src/AngleSharp.Css.Tests/CssConstructionFunctions.cs

@@ -98,6 +98,13 @@ internal static Predicate<IRenderDevice> CreateValidator(String name, String val
             return device => validator.Validate(feature, device);
         }
 
+        internal static Predicate<IRenderDevice> CreateBooleanValidator(String name)
+        {
+            var validator = CreateMediaFeatureValidator(name);
+            var feature = new MediaFeature(name);
+            return device => validator.Validate(feature, device);
+        }
+
         internal static CssFontFeatureValuesRule ParseFontFeatureValuesRule(String source)
         {
             ICssParser parser = new CssParser();