raroche · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026
diff --git a/.config/dotnet-tools.json b/.config/dotnet-tools.json
@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "docfx": {
-      "version": "2.78.5",
+      "version": "2.81.0",
       "commands": [
         "docfx"
       ],

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -11,9 +11,14 @@ Post-`1.1.0` improvements accumulate here until the next release is cut.
 A minor dependency refresh release that resolves the current AngleSharp vulnerability warning, consolidates the compatible open Dependabot runtime/test-tooling/CI action updates, and migrates code away from SkiaSharp APIs newly obsolete in SkiaSharp 4.x.
 
 ### Changed
-- Updated **AngleSharp** to 1.6.0 to resolve GHSA-pgww-w46g-26qg; **AngleSharp.Css** remains pinned to 1.0.0-beta.144 because stable 1.0.0 regresses background-image parsing/painting.
-- Updated bundled native/runtime dependencies to **SkiaSharp** 4.150.1 and **HarfBuzzSharp** 14.2.1.1.
-- Updated build and test tooling, including **Microsoft.NET.Test.Sdk** 18.8.1, **xunit.runner.visualstudio** 3.1.5, **coverlet.collector** 10.0.1, **BenchmarkDotNet** 0.15.8, and **Microsoft.SourceLink.GitHub** 10.0.301.
+- Updated **AngleSharp** to 1.8.2 (resolves GHSA-pgww-w46g-26qg).
+- Updated **AngleSharp.Css** from the 1.0.0-beta.144 prerelease to the stable **1.1.2**. Every runtime dependency is now a stable release, so the `NU5104` prerelease-dependency exception is gone.
+- Updated bundled native/runtime dependencies to **SkiaSharp** 4.153.1 and **HarfBuzzSharp** 14.2.1.301.
+- Updated build and test tooling, including **Microsoft.NET.Test.Sdk** 18.10.1, **xunit.runner.visualstudio** 4.0.0, **coverlet.collector** 10.1.0, **BenchmarkDotNet** 0.15.8, **Microsoft.Playwright** 1.63.0, **PDFtoImage** 5.4.0, **docfx** 2.81.0, and **Microsoft.SourceLink.GitHub** 10.0.401.
+
+### Fixed
+- `@layer` blocks now apply, in layer order. Previously their rules were dropped with `CSS-AT-RULE-UNKNOWN-001`.
+- An `!important` grid longhand now correctly beats a later normal shorthand in the same rule (for example `grid-row-end: 6 !important; grid-row: 2 / 4` now ends at line 6).
 - Updated CI actions to **actions/setup-dotnet** v6 and **github/codeql-action** v4.
 
 ## [1.0.2]

diff --git a/Directory.Build.props b/Directory.Build.props
@@ -28,12 +28,11 @@
     <NoWarn>$(NoWarn);CS1591</NoWarn> <!-- CS1591: missing XML doc on internals. -->
 
     <!--
-      NU5104 (a stable package has a prerelease dependency) is DELIBERATELY demoted from an error to
-      a VISIBLE warning rather than suppressed. NetPdf still depends on AngleSharp.Css 1.0.0-beta.144
-      because AngleSharp.Css 1.0.0 regresses background-image parsing/painting in the current test suite.
-      We do NOT hide it: pack emits NU5104 so the exception is auditable at release time.
+      NU5104 (a stable package has a prerelease dependency) is an ERROR again. It was demoted to a warning
+      while NetPdf depended on AngleSharp.Css 1.0.0-beta.144; AngleSharp.Css 1.1.2 is stable, so every
+      runtime dependency is now a stable release and the exception is removed. Do not re-add the demotion
+      without a written reason here.
     -->
-    <WarningsNotAsErrors>$(WarningsNotAsErrors);NU5104</WarningsNotAsErrors>
   </PropertyGroup>
 
   <!-- NuGet package authoring best practices. -->

diff --git a/Directory.Packages.props b/Directory.Packages.props
@@ -12,33 +12,40 @@
        review before being added here (see docs/clean-room-policy.md). -->
   <ItemGroup>
     <!--
-      AngleSharp.Css is HELD at beta.144. The stable 1.0.0 release regresses background-image rendering:
-      `background-image: url(...)` stops painting (the background-paint and multi-layer image tests drop to
-      zero image output) and several pre-pass recovery tests no longer observe the dropped opaque-rule slots.
-      AngleSharp itself is bumped for GHSA-pgww-w46g-26qg; keep AngleSharp.Css pinned until the parser
-      regression is diagnosed.
+      AngleSharp.Css 1.1.2 — the first STABLE release NetPdf can take. 1.0.0 and 1.0.1 were held back because
+      they broke background-image painting; 1.1.x fixes that (all background tests and every rendering golden
+      are unchanged). What 1.1.x changes, and what NetPdf does about it:
+        * It parses @container and @layer as real grouping rules instead of dropping them. The cascade still
+          SKIPS @container bodies (container queries are unsupported) and now APPLIES @layer bodies in layer
+          order — previously those were dropped. Pinned by CascadeCorpusTests.
+        * It expands a single-value `gap: 20px` / `grid-gap: 20px` into row-gap + an EMPTY column-gap
+          (a 1.1.x bug; CSS Box Alignment §8.3 says both get the value). CssParserAdapter repairs the empty
+          column gap from row-gap — see SingleValueGapTwin. Without it every one-value flex/grid gap is lost.
+        * Its per-rule dedup no longer discards an !important longhand before a later shorthand, so the
+          grid-row-end known gap closed upstream.
+      Before bumping it again: run the W3cConformance gates and CssParserAdapterPreprocessTests locally.
     -->
-    <PackageVersion Include="AngleSharp" Version="1.6.0" />
-    <PackageVersion Include="AngleSharp.Css" Version="1.0.0-beta.144" />
-    <PackageVersion Include="HarfBuzzSharp" Version="14.2.1.2" />
-    <PackageVersion Include="HarfBuzzSharp.NativeAssets.Linux" Version="14.2.1.2" />
-    <PackageVersion Include="HarfBuzzSharp.NativeAssets.macOS" Version="14.2.1.2" />
-    <PackageVersion Include="HarfBuzzSharp.NativeAssets.Win32" Version="14.2.1.2" />
-    <PackageVersion Include="SkiaSharp" Version="4.151.1" />
-    <PackageVersion Include="SkiaSharp.NativeAssets.Linux" Version="4.151.1" />
-    <PackageVersion Include="SkiaSharp.NativeAssets.macOS" Version="4.151.1" />
-    <PackageVersion Include="SkiaSharp.NativeAssets.Win32" Version="4.151.1" />
+    <PackageVersion Include="AngleSharp" Version="1.8.2" />
+    <PackageVersion Include="AngleSharp.Css" Version="1.1.2" />
+    <PackageVersion Include="HarfBuzzSharp" Version="14.2.1.301" />
+    <PackageVersion Include="HarfBuzzSharp.NativeAssets.Linux" Version="14.2.1.301" />
+    <PackageVersion Include="HarfBuzzSharp.NativeAssets.macOS" Version="14.2.1.301" />
+    <PackageVersion Include="HarfBuzzSharp.NativeAssets.Win32" Version="14.2.1.301" />
+    <PackageVersion Include="SkiaSharp" Version="4.153.1" />
+    <PackageVersion Include="SkiaSharp.NativeAssets.Linux" Version="4.153.1" />
+    <PackageVersion Include="SkiaSharp.NativeAssets.macOS" Version="4.153.1" />
+    <PackageVersion Include="SkiaSharp.NativeAssets.Win32" Version="4.153.1" />
   </ItemGroup>
 
   <!-- Test-only dependencies. -->
   <ItemGroup>
     <PackageVersion Include="xunit" Version="2.9.3" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="4.0.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
-    <PackageVersion Include="coverlet.collector" Version="10.0.1" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.10.1" />
+    <PackageVersion Include="coverlet.collector" Version="10.1.0" />
     <PackageVersion Include="BenchmarkDotNet" Version="0.15.8" />
     <PackageVersion Include="SharpFuzz" Version="2.3.0" />
-    <PackageVersion Include="Microsoft.Playwright" Version="1.62.0" />
+    <PackageVersion Include="Microsoft.Playwright" Version="1.63.0" />
     <!-- Visual-regression harness (PR 8): PDFium (via PDFtoImage, ships bblanchon.PDFium native for
          macOS/Linux/Win) rasterizes the NetPdf PDF -> RGBA; SkiaSharp only WRITES PDF.
          PDFtoImage 5.4.0 declares SkiaSharp 4.150.1, and production pins 4.151.1 just above it, so NuGet
@@ -67,7 +74,7 @@
 
   <!-- Build infrastructure. -->
   <ItemGroup>
-    <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="10.0.400" />
+    <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="10.0.401" />
   </ItemGroup>
 
 </Project>
diff --git a/src/NetPdf.Css/Parser/CssParserAdapter.cs b/src/NetPdf.Css/Parser/CssParserAdapter.cs
@@ -1094,7 +1094,10 @@ private static ImmutableArray<CssDeclaration> AdaptDeclarations(ICssStyleDeclara
     private static ImmutableArray<CssDeclaration> AdaptProperties(IEnumerable<ICssProperty> properties)
     {
         var output = ImmutableArray.CreateBuilder<CssDeclaration>();
-        foreach (var property in properties)
+        // Materialized once: the single-value-gap repair below needs to look at a SIBLING declaration
+        // (row-gap) that AngleSharp may emit after the one being repaired (column-gap).
+        var list = properties as IReadOnlyList<ICssProperty> ?? new List<ICssProperty>(properties);
+        foreach (var property in list)
         {
             if (property is null || string.IsNullOrEmpty(property.Name)) continue;
             // RC-13 — skip EMPTY-valued declarations, but ONLY for standard properties. AngleSharp expands
@@ -1113,7 +1116,30 @@ private static ImmutableArray<CssDeclaration> AdaptProperties(IEnumerable<ICssPr
             // removing an authored custom-property declaration (whose empty token stream is valid and must
             // reach VarResolver) should that upstream behavior change.
             var isCustomProperty = property.Name.StartsWith("--", StringComparison.Ordinal);
-            if (!isCustomProperty && string.IsNullOrWhiteSpace(property.Value)) continue;
+            if (!isCustomProperty && string.IsNullOrWhiteSpace(property.Value))
+            {
+                // AngleSharp.Css 1.1.x expands a SINGLE-value `gap: 20px` (and the legacy
+                // `grid-gap: 20px`) into `row-gap: 20px` + an EMPTY `column-gap`, instead of repeating
+                // the value as CSS Box Alignment L3 §8.3 requires ("if <column-gap> is omitted, it is
+                // set to the same value as <row-gap>"). 1.0.0-beta.144 got this right. Dropping the
+                // empty longhand (the rule above) would silently lose the column gap — the main-axis
+                // gap of every row flex container and every grid using the one-value form. Repair it
+                // from the sibling row gap, carrying that declaration's importance.
+                //
+                // Safe because an empty standard longhand is never authored CSS — it only ever comes
+                // out of shorthand expansion. And a `gap: var(--g)` expansion leaves row-gap empty too,
+                // so this does not fire there; the var() recovery path handles that case as before.
+                var twin = SingleValueGapTwin(property.Name, list);
+                if (twin is not null)
+                {
+                    output.Add(new CssDeclaration(
+                        Property: property.Name,
+                        Value: new CssValue(twin.Value!),
+                        IsImportant: twin.IsImportant,
+                        Location: CssSourceLocation.Unknown));
+                }
+                continue;
+            }
             output.Add(new CssDeclaration(
                 Property: property.Name,
                 Value: new CssValue(property.Value ?? string.Empty),
@@ -1125,6 +1151,29 @@ private static ImmutableArray<CssDeclaration> AdaptProperties(IEnumerable<ICssPr
             : output.ToImmutable();
     }
 
+    /// <summary>For an empty <c>column-gap</c> / <c>grid-column-gap</c>, returns the non-empty
+    /// <c>row-gap</c> / <c>grid-row-gap</c> declaration in the same block (the value a single-value
+    /// <c>gap</c> shorthand should have given both), or <see langword="null"/> if there is none.</summary>
+    private static ICssProperty? SingleValueGapTwin(string name, IReadOnlyList<ICssProperty> list)
+    {
+        string? rowName =
+            string.Equals(name, "column-gap", StringComparison.OrdinalIgnoreCase) ? "row-gap"
+            : string.Equals(name, "grid-column-gap", StringComparison.OrdinalIgnoreCase) ? "grid-row-gap"
+            : null;
+        if (rowName is null) return null;
+        for (var i = 0; i < list.Count; i++)
+        {
+            var candidate = list[i];
+            if (candidate is not null
+                && string.Equals(candidate.Name, rowName, StringComparison.OrdinalIgnoreCase)
+                && !string.IsNullOrWhiteSpace(candidate.Value))
+            {
+                return candidate;
+            }
+        }
+        return null;
+    }
+
     private static string NameFromType(ICssRule rule)
     {
         var name = rule.Type.ToString();

diff --git a/tests/NetPdf.RealDocuments/Css/CascadeCorpusTests.cs b/tests/NetPdf.RealDocuments/Css/CascadeCorpusTests.cs
@@ -202,14 +202,48 @@ @layer typography {
         var result = CascadeResolver.Resolve(document, sheets,
             CssMediaContext.DefaultPrint, sink);
 
-        // Outer p { color: red } applies. The @layer body's inner rule does not (v1 gap).
+        // AngleSharp.Css 1.1.x decomposes the @layer body, so the layered rule now reaches the cascade
+        // (under 1.0.0-beta.144 it arrived as an opaque RawBody and was dropped with
+        // CSS-AT-RULE-UNKNOWN-001). It must lose to the UNLAYERED rule: per CSS Cascade L5 §6.4,
+        // normal declarations in any layer rank below unlayered normal declarations — even though the
+        // layered rule comes later in source order.
         var p = document.QuerySelector("p")!;
-        Assert.NotNull(result.TryGetStylesFor(p)?.GetWinner("color"));
-        // Diagnostic emitted for the opaque @layer body.
-        Assert.Contains(sink.Diagnostics,
+        var winner = result.TryGetStylesFor(p)?.GetWinner("color");
+        Assert.NotNull(winner);
+        Assert.Equal("rgba(255, 0, 0, 1)", winner!.Declaration.Value.RawText); // red; AngleSharp normalizes to rgba()
+        // The body is no longer opaque, so the "preserved but not applied" diagnostic is gone.
+        Assert.DoesNotContain(sink.Diagnostics,
             d => d.Code == CssDiagnosticCodes.CssAtRuleUnknown001);
     }
 
+    [Fact]
+    public async Task Container_children_are_skipped_even_when_decomposed()
+    {
+        // AngleSharp.Css 1.1.x parses @container as a grouping rule and hands the cascade REAL child
+        // rules (1.0.0-beta.144 dropped the body entirely). A naive "walk every grouping rule" would
+        // therefore start applying container-query styles UNCONDITIONALLY. v1 does not evaluate
+        // container queries, so the children must stay skipped and the diagnostic must still fire.
+        var html = """
+            <html><head><style>
+              p { color: green; }
+              @container (min-width: 1px) {
+                p { color: red; }
+              }
+            </style></head><body><p>x</p></body></html>
+            """;
+        var host = new HtmlParsingHost();
+        var document = await host.ParseAsync(html, new HtmlPdfOptions());
+
+        var sheets = AdaptAllSheetsViaPreprocessor(document);
+        var sink = new CapturingSink();
+        var result = CascadeResolver.Resolve(document, sheets, CssMediaContext.DefaultPrint, sink);
+
+        var p = document.QuerySelector("p")!;
+        Assert.Equal("rgba(0, 128, 0, 1)", result.TryGetStylesFor(p)!.GetWinner("color")!.Declaration.Value.RawText); // green; AngleSharp normalizes to rgba()
+        Assert.Contains(sink.Diagnostics,
+            d => d.Code == CssDiagnosticCodes.CssContainerQueryUnsupported001);
+    }
+
     private static string LoadCorpusFile(string relativePath)
     {
         var path = System.IO.Path.Combine(System.AppContext.BaseDirectory, relativePath);

diff --git a/tests/NetPdf.RenderingCorpus/docker/Dockerfile b/tests/NetPdf.RenderingCorpus/docker/Dockerfile
@@ -3,7 +3,7 @@
 # Pin the Playwright version (which pins a specific Chromium revision) — NEVER use a floating tag — so the
 # committed reference PNGs are reproducible and CI (Linux) does not drift against a developer's macOS fonts.
 # Bump this tag deliberately as part of a reference-regeneration, never implicitly.
-FROM mcr.microsoft.com/playwright/python:v1.62.0-jammy
+FROM mcr.microsoft.com/playwright/python:v1.63.0-jammy
 
 # pypdfium2 rasterizes the Chrome print-to-PDF at the harness DPI (PDFium — SkiaSharp cannot read PDF).
 # Install playwright into the SAME python that runs the generator too: the base image ships Playwright but