diff --git a/.changeset/gentle-berries-decide.md b/.changeset/gentle-berries-decide.md
new file mode 100644
index 0000000000..643b1f0287
--- /dev/null
+++ b/.changeset/gentle-berries-decide.md
@@ -0,0 +1,5 @@
+---
+"@siteimprove/alfa-css": patch
+---
+
+**Added:** all `Value` subtype now correctly implement the `(Partially)Resovable` interfaces.
diff --git a/.changeset/pretty-waves-peel.md b/.changeset/pretty-waves-peel.md
new file mode 100644
index 0000000000..53efec6556
--- /dev/null
+++ b/.changeset/pretty-waves-peel.md
@@ -0,0 +1,5 @@
+---
+"@siteimprove/alfa-css": minor
+---
+
+**Breaking:** `Image.partiallyResolve()` and `Shape.partiallyResolve()` functions has been replaced by instance methods of the same name.
diff --git a/docs/review/api/alfa-css.api.md b/docs/review/api/alfa-css.api.md
index 44f90a0db7..25cc41cdab 100644
--- a/docs/review/api/alfa-css.api.md
+++ b/docs/review/api/alfa-css.api.md
@@ -27,6 +27,7 @@ export type Angle<U extends Unit.Angle = Unit.Angle> = Angle.Calculated | Angle.
 
 // @public (undocumented)
 export namespace Angle {
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export class Calculated extends Dimension.Calculated<"angle"> implements Resolvable<Canonical, never> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -45,7 +46,7 @@ export namespace Angle {
     }
     // (undocumented)
     export type Canonical = Fixed<"deg">;
-    // Warning: (ae-forgotten-export) The symbol "Resolvable" needs to be exported by the entry point index.d.ts
+    // Warning: (ae-incompatible-release-tags) The symbol "Fixed" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export class Fixed<U extends Unit.Angle = Unit.Angle> extends Dimension.Fixed<"angle", U> implements Resolvable<Canonical, never>, Comparable<Fixed<U>> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -97,6 +98,7 @@ export type AnglePercentage<U extends Unit.Angle = Unit.Angle> = AnglePercentage
 
 // @public (undocumented)
 export namespace AnglePercentage {
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export class Calculated extends Dimension.Calculated<"angle-percentage"> implements Resolvable<Canonical, never> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -211,7 +213,8 @@ export namespace Box {
 }
 
 // Warning: (ae-forgotten-export) The symbol "BasicShape" needs to be exported by the entry point index.d.ts
-// Warning: (ae-forgotten-export) The symbol "PartiallyResolvable" needs to be exported by the entry point index.d.ts
+// Warning: (ae-incompatible-release-tags) The symbol "Circle" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Circle" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
 //
 // @public (undocumented)
 export class Circle<R extends Radius = Radius, P extends Position = Position> extends BasicShape<"circle", Value.HasCalculation<[R, P]>> implements Resolvable<Circle.Canonical, Circle.Resolver>, PartiallyResolvable<Circle.PartiallyResolved, Circle.PartialResolver> {
@@ -397,6 +400,8 @@ export namespace Dimension {
     // Warning: (ae-forgotten-export) The symbol "Type" needs to be exported by the entry point index.d.ts
     // Warning: (ae-forgotten-export) The symbol "DBase" needs to be exported by the entry point index.d.ts
     // Warning: (ae-forgotten-export) The symbol "DCanonicalUnit" needs to be exported by the entry point index.d.ts
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
     export abstract class Calculated<T extends Type = Type, PR extends Type = T> extends Numeric.Calculated<T, DBase[T], PR> implements Resolvable<Fixed<DBase[T], DCanonicalUnit[DBase[T]]>, unknown>, PartiallyResolvable<any, any> {
         protected constructor(math: Numeric.ToMath<T>, type: T);
         // (undocumented)
@@ -414,6 +419,7 @@ export namespace Dimension {
     }
     // Warning: (ae-forgotten-export) The symbol "Numeric_2" needs to be exported by the entry point index.d.ts
     // Warning: (ae-forgotten-export) The symbol "DUnit" needs to be exported by the entry point index.d.ts
+    // Warning: (ae-incompatible-release-tags) The symbol "Fixed" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export abstract class Fixed<T extends Numeric_2.Dimension = Numeric_2.Dimension, U extends DUnit[T] = DUnit[T]> extends Numeric.Fixed<T> implements Resolvable<Fixed<T, DCanonicalUnit[T]>, unknown>, Convertible<DUnit[T]>, Comparable<Fixed<T>> {
         protected constructor(value: number, unit: U, type: T);
         // (undocumented)
@@ -457,6 +463,9 @@ export namespace Dimension {
     export function isFixed(value: unknown): value is Fixed;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Ellipse" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Ellipse" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Ellipse<R extends Radius = Radius, P extends Position = Position> extends BasicShape<"ellipse", Value.HasCalculation<[R, P]>> implements Resolvable<Ellipse.Canonical, Ellipse.Resolver>, PartiallyResolvable<Ellipse.PartiallyResolved, Ellipse.PartialResolver> {
     // (undocumented)
@@ -663,8 +672,11 @@ export namespace HSL {
     parse: Parser<HSL>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Image" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Image" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public (undocumented)
-export class Image<I extends URL | Gradient = URL | Gradient> extends Value<"image", Value.HasCalculation<[I]>> {
+export class Image<I extends URL | Gradient = URL | Gradient> extends Value<"image", Value.HasCalculation<[I]>> implements Resolvable<Image.Canonical, Image.Resolver>, PartiallyResolvable<Image.PartiallyResolved, Image.PartialResolver> {
     // (undocumented)
     equals(value: unknown): value is this;
     // (undocumented)
@@ -674,6 +686,8 @@ export class Image<I extends URL | Gradient = URL | Gradient> extends Value<"ima
     // (undocumented)
     static of<I extends URL | Gradient>(image: I): Image<I>;
     // (undocumented)
+    partiallyResolve(resolver: Image.PartialResolver): Image.PartiallyResolved;
+    // (undocumented)
     resolve(resolver: Image.Resolver): Image.Canonical;
     // (undocumented)
     toJSON(): Image.JSON;
@@ -693,8 +707,6 @@ export namespace Image {
         image: URL.JSON | Gradient.JSON;
     }
     // (undocumented)
-    export function partiallyResolve(resolver: PartialResolver): (value: Image) => PartiallyResolved;
-    // (undocumented)
     export type PartiallyResolved = Image<URL.Canonical | Gradient.PartiallyResolved>;
     // (undocumented)
     export type PartialResolver = URL.Resolver & Gradient.PartialResolver;
@@ -706,6 +718,8 @@ export namespace Image {
 
 // Warning: (ae-forgotten-export) The symbol "Corner_2" needs to be exported by the entry point index.d.ts
 // Warning: (ae-forgotten-export) The symbol "HasCalculation" needs to be exported by the entry point index.d.ts
+// Warning: (ae-incompatible-release-tags) The symbol "Inset" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Inset" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
 //
 // @public (undocumented)
 export class Inset<O extends Inset.Offset = Inset.Offset, C extends Corner_2 = Corner_2> extends BasicShape<"inset", HasCalculation<O, C>> implements Resolvable<Inset.Canonical, Inset.Resolver>, PartiallyResolvable<Inset.PartiallyResolved, Inset.PartialResolver> {
@@ -777,6 +791,7 @@ export type Integer = Integer.Calculated | Integer.Fixed;
 
 // @public (undocumented)
 export namespace Integer {
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export class Calculated extends Numeric.Calculated<"number"> implements Resolvable<Canonical, never> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -797,6 +812,7 @@ export namespace Integer {
     }
     // (undocumented)
     export type Canonical = Fixed;
+    // Warning: (ae-incompatible-release-tags) The symbol "Fixed" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export class Fixed extends Numeric.Fixed<"number"> implements Resolvable<Canonical, never> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -837,6 +853,8 @@ export namespace Integer {
     parse: Parser<Integer>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Keyword" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Keyword<T extends string = string> extends Value<"keyword", false> implements Resolvable<Keyword<T>, never> {
     // (undocumented)
@@ -876,6 +894,7 @@ export type Length<U extends Unit.Length = Unit.Length> = Length.Calculated | Le
 
 // @public (undocumented)
 export namespace Length {
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export class Calculated extends Dimension.Calculated<"length"> implements Resolvable<Canonical, Resolver> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -894,6 +913,7 @@ export namespace Length {
     }
     // (undocumented)
     export type Canonical = Fixed<"px">;
+    // Warning: (ae-incompatible-release-tags) The symbol "Fixed" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export class Fixed<U extends Unit.Length = Unit.Length> extends Dimension.Fixed<"length", U> implements Resolvable<Canonical, Resolver>, Comparable<Fixed<U>> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -956,6 +976,8 @@ export type LengthPercentage<U extends Unit.Length = Unit.Length> = LengthPercen
 
 // @public (undocumented)
 export namespace LengthPercentage {
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
     export class Calculated extends Dimension.Calculated<"length-percentage"> implements Resolvable<Length.Canonical, Resolver>, PartiallyResolvable<Calculated, PartialResolver> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -1017,6 +1039,9 @@ export namespace Lexer {
     export function lex(input: string): Slice<Token>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "List" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "List" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class List<V extends Value> extends Value<"list", Value.HasCalculation<[V]>> implements Iterable_2<V>, Resolvable<List<Resolvable.Resolved<V>>, Resolvable.Resolver<V>>, PartiallyResolvable<List<Resolvable.PartiallyResolved<V>>, Resolvable.PartialResolver<V>> {
     // (undocumented)
@@ -1148,6 +1173,7 @@ namespace Math_2 {
 export { Math_2 as Math }
 
 // Warning: (ae-forgotten-export) The symbol "Function_3" needs to be exported by the entry point index.d.ts
+// Warning: (ae-incompatible-release-tags) The symbol "Matrix" is marked as @public, but its signature references "Resolvable" which is marked as @internal
 //
 // @public (undocumented)
 export class Matrix extends Function_3<"matrix", false> implements Resolvable<Matrix.Canonical, never> {
@@ -1295,6 +1321,7 @@ type Number_2 = Number_2.Calculated | Number_2.Fixed;
 
 // @public (undocumented)
 namespace Number_2 {
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     class Calculated extends Numeric.Calculated<"number"> implements Resolvable<Canonical, never> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -1315,6 +1342,7 @@ namespace Number_2 {
     }
     // (undocumented)
     type Canonical = Fixed;
+    // Warning: (ae-incompatible-release-tags) The symbol "Fixed" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     class Fixed extends Numeric.Fixed<"number"> implements Resolvable<Canonical, never> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -1359,6 +1387,7 @@ export type Numeric<T extends Numeric.Type = Numeric.Type> = Numeric.Calculated<
 
 // @public (undocumented)
 export namespace Numeric {
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export abstract class Calculated<T extends Type = Type, R extends Type = T, PR extends Type = R> extends Value<T, true, R, PR> implements Resolvable<Fixed<R>, never> {
         // Warning: (ae-incompatible-release-tags) The symbol "__constructor" is marked as @public, but its signature references "Numeric" which is marked as @internal
         protected constructor(math: ToMath<T>, type: T);
@@ -1393,6 +1422,7 @@ export namespace Numeric {
             math: Serializable.ToJSON<ToMath<T>>;
         }
     }
+    // Warning: (ae-incompatible-release-tags) The symbol "Fixed" is marked as @public, but its signature references "Resolvable" which is marked as @internal
     export abstract class Fixed<T extends Type = Type, R extends Type = T, PR extends Type = R> extends Value<T, false, R, PR> implements Resolvable<Fixed<R>, never>, Comparable<Fixed> {
         protected constructor(value: number, type: T);
         // (undocumented)
@@ -1443,11 +1473,21 @@ export namespace Numeric {
 // @public (undocumented)
 export type Parser<V> = Parser_2<Slice<Token>, V, string>;
 
+// Warning: (ae-internal-missing-underscore) The name "PartiallyResolvable" should be prefixed with an underscore because the declaration is marked as @internal
+//
+// @internal
+export interface PartiallyResolvable<V extends Value<string>, in R> {
+    // (undocumented)
+    partiallyResolve(resolver?: R): V;
+}
+
 // @public (undocumented)
 export type Percentage<H extends Numeric_2.Type = Numeric_2.Type> = Percentage.Calculated<H> | Percentage.Fixed<H>;
 
 // @public (undocumented)
 export namespace Percentage {
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+    // Warning: (ae-incompatible-release-tags) The symbol "Calculated" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
     export class Calculated<H extends Numeric_2.Type = Numeric_2.Type> extends Numeric.Calculated<"percentage", H, "percentage"> implements Resolvable<Canonicals[H], Resolver<H>>, PartiallyResolvable<PartiallyResolved<H>, PartialResolver> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -1458,7 +1498,7 @@ export namespace Percentage {
         // (undocumented)
         partiallyResolve(): PartiallyResolved<H>;
         // (undocumented)
-        resolve(): Canonical;
+        resolve(): Fixed<H>;
         // (undocumented)
         resolve<T extends Canonicals[H]>(resolver: Resolver<H>): T;
         // (undocumented)
@@ -1471,8 +1511,10 @@ export namespace Percentage {
         }
     }
     // (undocumented)
-    export type Canonical = Fixed;
+    export type Canonical = Fixed<"percentage">;
     // Warning: (ae-forgotten-export) The symbol "Canonicals" needs to be exported by the entry point index.d.ts
+    // Warning: (ae-incompatible-release-tags) The symbol "Fixed" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+    // Warning: (ae-incompatible-release-tags) The symbol "Fixed" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
     export class Fixed<H extends Numeric_2.Type = Numeric_2.Type> extends Numeric.Fixed<"percentage", "percentage" | H, "percentage"> implements Resolvable<Canonical | Canonicals[H], Resolver<H>>, PartiallyResolvable<PartiallyResolved<H>, PartialResolver> {
         // (undocumented)
         equals(value: unknown): value is this;
@@ -1521,6 +1563,8 @@ export namespace Percentage {
     };
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Perspective" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Perspective<D extends Length = Length> extends Function_3<"perspective", Value.HasCalculation<[D]>> implements Resolvable<Perspective.Canonical, Perspective.Resolver> {
     // (undocumented)
@@ -1556,6 +1600,9 @@ export namespace Perspective {
     parse: Parser_2<Slice<Token>, Perspective<Length<import("../..").Unit.Length>>, string, []>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Polygon" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Polygon" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Polygon<F extends Polygon.Fill = Polygon.Fill, V extends LengthPercentage = LengthPercentage> extends BasicShape<"polygon", Value.HasCalculation<[V]>> implements Resolvable<Polygon.Canonical, Polygon.Resolver>, PartiallyResolvable<Polygon.PartiallyResolved, Polygon.PartialResolver> {
     // (undocumented)
@@ -1610,6 +1657,9 @@ export namespace Polygon {
     parse: Parser<Polygon>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Position" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Position" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Position<H extends Position.Keywords.Horizontal = Position.Keywords.Horizontal, V extends Position.Keywords.Vertical = Position.Keywords.Vertical, HC extends Position.Component<H> = Position.Component<H>, VC extends Position.Component<V> = Position.Component<V>> extends Value<"position", Value.HasCalculation<[HC, VC]>> implements Resolvable<Position.Canonical<H, V>, Position.Resolver>, PartiallyResolvable<Position.PartiallyResolved<H, V>, Position.PartialResolver> {
     // (undocumented)
@@ -1662,6 +1712,9 @@ export namespace Position {
     }
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Radius" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Radius" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Radius<R extends LengthPercentage | Radius.Side = LengthPercentage | Radius.Side> extends BasicShape<"radius", Value.HasCalculation<[R]>> implements Resolvable<Radius.Canonical, Radius.Resolver>, PartiallyResolvable<Radius.PartiallyResolved, Radius.PartialResolver> {
     // (undocumented)
@@ -1714,8 +1767,10 @@ export namespace Radius {
     parse: Parser<Radius>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Rectangle" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+//
 // @public @deprecated (undocumented)
-export class Rectangle<O extends Length | Rectangle.Auto = Length | Rectangle.Auto> extends BasicShape<"rectangle", Value.HasCalculation<[O, O, O, O]>> {
+export class Rectangle<O extends Length | Rectangle.Auto = Length | Rectangle.Auto> extends BasicShape<"rectangle", Value.HasCalculation<[O, O, O, O]>> implements Resolvable<Rectangle.Canonical, Rectangle.Resolver> {
     // (undocumented)
     get bottom(): O;
     // (undocumented)
@@ -1773,6 +1828,25 @@ export namespace Rectangle {
     parse: Parser<Rectangle>;
 }
 
+// Warning: (ae-internal-missing-underscore) The name "Resolvable" should be prefixed with an underscore because the declaration is marked as @internal
+//
+// @internal (undocumented)
+export interface Resolvable<V extends Value<string, false>, in R> {
+    // (undocumented)
+    resolve(resolver?: R): V;
+}
+
+// @internal (undocumented)
+export namespace Resolvable {
+    export type PartiallyResolved<V extends Value> = V extends PartiallyResolvable<infer U, unknown> ? U : never;
+    export type PartialResolver<V extends Value> = UnionToIntersection<V extends PartiallyResolvable<Value<string, false>, never> ? never : V extends PartiallyResolvable<Value<string, false>, infer R> ? R : never>;
+    export type Resolved<V extends Value> = V extends Resolvable<infer U, unknown> ? U : never;
+    export type Resolver<V extends Value> = UnionToIntersection<V extends Resolvable<Value<string, false>, never> ? never : V extends Resolvable<Value<string, false>, infer R> ? R : never>;
+    // (undocumented)
+    export type UnionToIntersection<U> = (U extends any ? (k: U) => void : never) extends (k: infer I) => void ? I : never;
+        {};
+}
+
 // @public (undocumented)
 export class RGB<C extends Number_2.Canonical | Percentage.Canonical = Number_2.Canonical | Percentage.Fixed<"percentage">, A extends Number_2.Canonical | Percentage.Canonical = Number_2.Canonical | Percentage.Fixed<"percentage">> extends Format<"rgb"> {
     // (undocumented)
@@ -1822,6 +1896,8 @@ export namespace RGB {
     parse: Parser<RGB>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Rotate" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Rotate extends Function_3<"rotate", false> implements Resolvable<Rotate.Canonical, never> {
     // (undocumented)
@@ -1867,6 +1943,8 @@ export namespace Rotate {
     parse: Parser_2<Slice<Token>, Rotate, string, []>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Scale" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Scale extends Function_3<"scale", false> implements Resolvable<Scale.Canonical, never> {
     // (undocumented)
@@ -1906,6 +1984,8 @@ export namespace Scale {
     parse: Parser_2<Slice<Token>, Scale, string, []>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Shadow" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Shadow<H extends Length = Length, V extends Length = H, B extends Length = Length, S extends Length = Length, C extends Color = Color> extends Value<"shadow", Value.HasCalculation<[H, V, B, S, C]>> implements Resolvable<Shadow.Canonical, Shadow.Resolver> {
     // (undocumented)
@@ -1968,8 +2048,11 @@ export namespace Shadow {
     export type Resolver = Length.Resolver;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Shape" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Shape" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public (undocumented)
-export class Shape<S extends Shape.Basic = Shape.Basic, B extends Box.Geometry = Box.Geometry> extends Value<"shape", Value.HasCalculation<[S]>> {
+export class Shape<S extends Shape.Basic = Shape.Basic, B extends Box.Geometry = Box.Geometry> extends Value<"shape", Value.HasCalculation<[S]>> implements Resolvable<Shape.Canonical, Shape.Resolver>, PartiallyResolvable<Shape.PartiallyResolved, Shape.PartialResolver> {
     // (undocumented)
     get box(): B;
     // (undocumented)
@@ -1981,6 +2064,8 @@ export class Shape<S extends Shape.Basic = Shape.Basic, B extends Box.Geometry =
     // (undocumented)
     static of<S extends Shape.Basic = Shape.Basic, B extends Box.Geometry = Box.Geometry>(shape: S, box: B): Shape<S, B>;
     // (undocumented)
+    partiallyResolve(resolver: Shape.PartialResolver): Shape.PartiallyResolved;
+    // (undocumented)
     resolve(resolver: Shape.Resolver): Shape.Canonical;
     // (undocumented)
     get shape(): S;
@@ -2024,8 +2109,6 @@ export namespace Shape {
         shape: Basic.JSON;
     }
     // (undocumented)
-    export function partiallyResolve(resolver: PartialResolver): (value: Shape) => PartiallyResolved;
-    // (undocumented)
     export type PartiallyResolved = Shape<Basic.PartiallyResolved, Box.Geometry>;
     // (undocumented)
     export type PartialResolver = Basic.PartialResolver;
@@ -2033,9 +2116,10 @@ export namespace Shape {
     export type Resolver = Basic.Resolver;
     const // (undocumented)
     parse: Parser<Shape<Circle | Ellipse | Inset | Polygon>>;
-        {};
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Skew" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Skew extends Function_3<"skew", false> implements Resolvable<Skew.Canonical, never> {
     // (undocumented)
@@ -2073,6 +2157,8 @@ export namespace Skew {
     parse: Parser_2<Slice<Token>, Skew, string, []>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "String" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+//
 // @public (undocumented)
 class String_2 extends Value<"string", false> implements Resolvable<String_2, never> {
     // (undocumented)
@@ -2922,6 +3008,9 @@ export namespace Transform {
     parseList: Parser<List<Transform>>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Translate" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Translate" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Translate<X extends LengthPercentage = LengthPercentage, Y extends LengthPercentage = LengthPercentage, Z extends Length = Length> extends Function_3<"translate", Value.HasCalculation<[X, Y, Z]>> implements Resolvable<Translate.Canonical, Translate.Resolver>, PartiallyResolvable<Translate.PartiallyResolved, Translate.PartialResolver> {
     // (undocumented)
@@ -2971,6 +3060,9 @@ export namespace Translate {
     parse: Parser<Translate>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Tuple" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Tuple" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public (undocumented)
 export class Tuple<T extends Array<Value>> extends Value<"tuple", Value.HasCalculation<T>> implements Resolvable<Tuple<Tuple.Resolved<T>>, Tuple.Resolver<T>>, PartiallyResolvable<Tuple<Tuple.PartiallyResolved<T>>, Tuple.PartialResolver<T>> {
     // (undocumented)
@@ -3002,11 +3094,15 @@ export namespace Tuple {
         // (undocumented)
         values: Serializable.ToJSON<T>;
     }
+    // Warning: (ae-incompatible-release-tags) The symbol "PartiallyResolved" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+    //
     // (undocumented)
     export type PartiallyResolved<T extends Array<Value>> = T extends [
     infer Head extends Value,
     ...infer Tail extends Array<Value>
     ] ? [Resolvable.PartiallyResolved<Head>, ...PartiallyResolved<Tail>] : [];
+    // Warning: (ae-incompatible-release-tags) The symbol "PartialResolver" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+    //
     // (undocumented)
     export type PartialResolver<T extends Array<Value>> = T extends Array<infer V extends Value> ? Resolvable.PartialResolver<V> : never;
     // @internal
@@ -3072,8 +3168,10 @@ export namespace Unit {
     export type Time = "s" | "ms";
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "URL" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+//
 // @public (undocumented)
-export class URL extends Value<"url", false> {
+export class URL extends Value<"url", false> implements Resolvable<URL, never> {
     // (undocumented)
     equals(value: unknown): value is this;
     // (undocumented)
@@ -3107,6 +3205,9 @@ export namespace URL {
     parse: Parser<URL>;
 }
 
+// Warning: (ae-incompatible-release-tags) The symbol "Value" is marked as @public, but its signature references "Resolvable" which is marked as @internal
+// Warning: (ae-incompatible-release-tags) The symbol "Value" is marked as @public, but its signature references "PartiallyResolvable" which is marked as @internal
+//
 // @public
 export abstract class Value<T extends string = string, CALC extends boolean = boolean, R extends string = T, PR extends string = R> implements Equatable, Hashable, Serializable<Value.JSON<T>>, Resolvable<Value<R, false>, Resolvable.Resolver<Value>>, PartiallyResolvable<Value<PR>, Resolvable.PartialResolver<Value>> {
     protected constructor(type: T, hasCalculation: CALC);
diff --git a/docs/review/api/alfa-style.api.md b/docs/review/api/alfa-style.api.md
index 3e19a66435..006f52590b 100644
--- a/docs/review/api/alfa-style.api.md
+++ b/docs/review/api/alfa-style.api.md
@@ -35,6 +35,7 @@ import { Percentage } from '@siteimprove/alfa-css';
 import { Position } from '@siteimprove/alfa-css';
 import { Predicate } from '@siteimprove/alfa-predicate';
 import { Rectangle } from '@siteimprove/alfa-css';
+import type { Resolvable } from '@siteimprove/alfa-css';
 import { Rotate } from '@siteimprove/alfa-css';
 import { Serializable } from '@siteimprove/alfa-json';
 import { Shadow } from '@siteimprove/alfa-css';
@@ -136,7 +137,7 @@ export namespace Longhands {
         readonly "border-end-start-radius": Longhand<Tuple<[horizontal: LengthPercentage, vertical: LengthPercentage]>, Tuple<[horizontal: LengthPercentage, vertical: LengthPercentage]>>;
         readonly "border-image-outset": Longhand<Specified_2, Tuple<[top: Length | Number_2, right: Length | Number_2, bottom: Length | Number_2, left: Length | Number_2]>>;
         readonly "border-image-repeat": Longhand<Specified_4, Specified_4>;
-        readonly "border-image-slice": Longhand<Specified_6, Specified_6>;
+        readonly "border-image-slice": Longhand<Specified_6, Tuple<[top: Number_2.Fixed | Percentage.Canonical, right: Number_2.Fixed | Percentage.Canonical, bottom: Number_2.Fixed | Percentage.Canonical, left: Number_2.Fixed | Percentage.Canonical]> | Tuple<[top: Number_2.Fixed | Percentage.Canonical, right: Number_2.Fixed | Percentage.Canonical, bottom: Number_2.Fixed | Percentage.Canonical, left: Number_2.Fixed | Percentage.Canonical, fill: Keyword<"fill">]>>;
         readonly "border-image-source": Longhand<Specified_7, Image.PartiallyResolved | Keyword<"none">>;
         readonly "border-image-width": Longhand<Specified_8, Tuple<[top: Number_2.Fixed | LengthPercentage | Keyword<"auto">, right: Number_2.Fixed | LengthPercentage | Keyword<"auto">, bottom: Number_2.Fixed | LengthPercentage | Keyword<"auto">, left: Number_2.Fixed | LengthPercentage | Keyword<"auto">]>>;
         readonly "border-inline-end-color": Longhand<Color, Color.Canonical>;
@@ -163,14 +164,14 @@ export namespace Longhands {
         readonly "clip-path": Longhand<URL | Keyword<"none"> | Shape<Shape.Basic, Box.Geometry>, URL | Keyword<"none"> | Shape<Shape.Basic, Box.Geometry>>;
         readonly clip: Longhand<Keyword<"auto"> | Shape<Rectangle<Length | Rectangle.Auto>, Keyword<"border-box">>, Keyword<"auto"> | Shape<Rectangle<Length | Rectangle.Auto>, Keyword<"border-box">>>;
         readonly color: Longhand<Color, Color.Canonical>;
-        readonly cursor: Longhand<Tuple<[List<URL | Tuple<[URL, Number_2, Number_2]>>, Keyword<"auto"> | Keyword<"none"> | Keyword<"default"> | Keyword<"context-menu"> | Keyword<"help"> | Keyword<"pointer"> | Keyword<"progress"> | Keyword<"wait"> | Keyword<"cell"> | Keyword<"crosshair"> | Keyword<"text"> | Keyword<"vertical-text"> | Keyword<"alias"> | Keyword<"copy"> | Keyword<"move"> | Keyword<"no-drop"> | Keyword<"not-allowed"> | Keyword<"grab"> | Keyword<"grabbing"> | Keyword<"e-resize"> | Keyword<"n-resize"> | Keyword<"ne-resize"> | Keyword<"nw-resize"> | Keyword<"s-resize"> | Keyword<"se-resize"> | Keyword<"sw-resize"> | Keyword<"w-resize"> | Keyword<"ew-resize"> | Keyword<"ns-resize"> | Keyword<"nesw-resize"> | Keyword<"nwse-resize"> | Keyword<"col-resize"> | Keyword<"row-resize"> | Keyword<"all-scroll"> | Keyword<"zoom-in"> | Keyword<"zoom-out">]>, Tuple<[List<URL | Tuple<[URL, Number_2, Number_2]>>, Keyword<"auto"> | Keyword<"none"> | Keyword<"default"> | Keyword<"context-menu"> | Keyword<"help"> | Keyword<"pointer"> | Keyword<"progress"> | Keyword<"wait"> | Keyword<"cell"> | Keyword<"crosshair"> | Keyword<"text"> | Keyword<"vertical-text"> | Keyword<"alias"> | Keyword<"copy"> | Keyword<"move"> | Keyword<"no-drop"> | Keyword<"not-allowed"> | Keyword<"grab"> | Keyword<"grabbing"> | Keyword<"e-resize"> | Keyword<"n-resize"> | Keyword<"ne-resize"> | Keyword<"nw-resize"> | Keyword<"s-resize"> | Keyword<"se-resize"> | Keyword<"sw-resize"> | Keyword<"w-resize"> | Keyword<"ew-resize"> | Keyword<"ns-resize"> | Keyword<"nesw-resize"> | Keyword<"nwse-resize"> | Keyword<"col-resize"> | Keyword<"row-resize"> | Keyword<"all-scroll"> | Keyword<"zoom-in"> | Keyword<"zoom-out">]>>;
+        readonly cursor: Longhand<Tuple<[List<URL | Tuple<[URL, Number_2, Number_2]>>, Keyword<"auto"> | Keyword<"none"> | Keyword<"default"> | Keyword<"context-menu"> | Keyword<"help"> | Keyword<"pointer"> | Keyword<"progress"> | Keyword<"wait"> | Keyword<"cell"> | Keyword<"crosshair"> | Keyword<"text"> | Keyword<"vertical-text"> | Keyword<"alias"> | Keyword<"copy"> | Keyword<"move"> | Keyword<"no-drop"> | Keyword<"not-allowed"> | Keyword<"grab"> | Keyword<"grabbing"> | Keyword<"e-resize"> | Keyword<"n-resize"> | Keyword<"ne-resize"> | Keyword<"nw-resize"> | Keyword<"s-resize"> | Keyword<"se-resize"> | Keyword<"sw-resize"> | Keyword<"w-resize"> | Keyword<"ew-resize"> | Keyword<"ns-resize"> | Keyword<"nesw-resize"> | Keyword<"nwse-resize"> | Keyword<"col-resize"> | Keyword<"row-resize"> | Keyword<"all-scroll"> | Keyword<"zoom-in"> | Keyword<"zoom-out">]>, Tuple<[List<URL | Tuple<[URL, Number_2.Fixed, Number_2.Fixed]>>, Keyword<"auto"> | Keyword<"none"> | Keyword<"default"> | Keyword<"context-menu"> | Keyword<"help"> | Keyword<"pointer"> | Keyword<"progress"> | Keyword<"wait"> | Keyword<"cell"> | Keyword<"crosshair"> | Keyword<"text"> | Keyword<"vertical-text"> | Keyword<"alias"> | Keyword<"copy"> | Keyword<"move"> | Keyword<"no-drop"> | Keyword<"not-allowed"> | Keyword<"grab"> | Keyword<"grabbing"> | Keyword<"e-resize"> | Keyword<"n-resize"> | Keyword<"ne-resize"> | Keyword<"nw-resize"> | Keyword<"s-resize"> | Keyword<"se-resize"> | Keyword<"sw-resize"> | Keyword<"w-resize"> | Keyword<"ew-resize"> | Keyword<"ns-resize"> | Keyword<"nesw-resize"> | Keyword<"nwse-resize"> | Keyword<"col-resize"> | Keyword<"row-resize"> | Keyword<"all-scroll"> | Keyword<"zoom-in"> | Keyword<"zoom-out">]>>;
         readonly display: Longhand<Tuple<[outside: Keyword<"block"> | Keyword<"inline"> | Keyword<"run-in">, inside: Keyword<"flow"> | Keyword<"flow-root"> | Keyword<"table"> | Keyword<"flex"> | Keyword<"grid"> | Keyword<"ruby">]> | Tuple<[outside: Keyword<"block"> | Keyword<"inline"> | Keyword<"run-in">, inside: Keyword<"flow"> | Keyword<"flow-root"> | Keyword<"table"> | Keyword<"flex"> | Keyword<"grid"> | Keyword<"ruby">, listitem: Keyword<"list-item">]> | Tuple<[outside: Keyword<"table-row-group"> | Keyword<"table-header-group"> | Keyword<"table-footer-group"> | Keyword<"table-row"> | Keyword<"table-cell"> | Keyword<"table-column-group"> | Keyword<"table-column"> | Keyword<"table-caption"> | Keyword<"ruby-base"> | Keyword<"ruby-text"> | Keyword<"ruby-base-container"> | Keyword<"ruby-text-container">, inside: Keyword<"flow"> | Keyword<"flow-root"> | Keyword<"table"> | Keyword<"flex"> | Keyword<"grid"> | Keyword<"ruby">]> | Tuple<[Keyword<"none"> | Keyword<"contents">]>, Tuple<[outside: Keyword<"block"> | Keyword<"inline"> | Keyword<"run-in">, inside: Keyword<"flow"> | Keyword<"flow-root"> | Keyword<"table"> | Keyword<"flex"> | Keyword<"grid"> | Keyword<"ruby">]> | Tuple<[outside: Keyword<"block"> | Keyword<"inline"> | Keyword<"run-in">, inside: Keyword<"flow"> | Keyword<"flow-root"> | Keyword<"table"> | Keyword<"flex"> | Keyword<"grid"> | Keyword<"ruby">, listitem: Keyword<"list-item">]> | Tuple<[outside: Keyword<"table-row-group"> | Keyword<"table-header-group"> | Keyword<"table-footer-group"> | Keyword<"table-row"> | Keyword<"table-cell"> | Keyword<"table-column-group"> | Keyword<"table-column"> | Keyword<"table-caption"> | Keyword<"ruby-base"> | Keyword<"ruby-text"> | Keyword<"ruby-base-container"> | Keyword<"ruby-text-container">, inside: Keyword<"flow"> | Keyword<"flow-root"> | Keyword<"table"> | Keyword<"flex"> | Keyword<"grid"> | Keyword<"ruby">]> | Tuple<[Keyword<"none"> | Keyword<"contents">]>>;
         readonly "flex-direction": Longhand<Keyword.ToKeywords<"row" | "row-reverse" | "column" | "column-reverse">, Keyword.ToKeywords<"row" | "row-reverse" | "column" | "column-reverse">>;
         readonly "flex-wrap": Longhand<Keyword.ToKeywords<"nowrap" | "wrap" | "wrap-reverse">, Keyword.ToKeywords<"nowrap" | "wrap" | "wrap-reverse">>;
         readonly float: Longhand<Keyword.ToKeywords<"none" | "left" | "right">, Keyword.ToKeywords<"none" | "left" | "right">>;
         readonly "font-family": Longhand<List<String_2 | Keyword<"serif"> | Keyword<"sans-serif"> | Keyword<"cursive"> | Keyword<"fantasy"> | Keyword<"monospace">>, List<String_2 | Keyword<"serif"> | Keyword<"sans-serif"> | Keyword<"cursive"> | Keyword<"fantasy"> | Keyword<"monospace">>>;
         readonly "font-size": Longhand<LengthPercentage | Keyword<"medium"> | Keyword<"xx-small"> | Keyword<"x-small"> | Keyword<"small"> | Keyword<"large"> | Keyword<"x-large"> | Keyword<"xx-large"> | Keyword<"xxx-large"> | Keyword<"larger"> | Keyword<"smaller">, Length>;
-        readonly "font-stretch": Longhand<Specified_10, Percentage.Fixed<Numeric.Type> | Percentage.Calculated<Numeric.Type>>;
+        readonly "font-stretch": Longhand<Specified_10, Percentage.Calculated<Numeric.Type> | Percentage.Fixed<Numeric.Type>>;
         readonly "font-style": Longhand<Keyword.ToKeywords<"normal" | "italic" | "oblique">, Keyword.ToKeywords<"normal" | "italic" | "oblique">>;
         readonly "font-variant-caps": Longhand<Keyword.ToKeywords<"normal" | "small-caps" | "all-small-caps" | "petite-caps" | "all-petite-caps" | "unicase" | "titling-caps">, Keyword.ToKeywords<"normal" | "small-caps" | "all-small-caps" | "petite-caps" | "all-petite-caps" | "unicase" | "titling-caps">>;
         readonly "font-variant-east-asian": Longhand<Specified_11, Specified_11>;
@@ -216,7 +217,7 @@ export namespace Longhands {
         readonly "vertical-align": Longhand<LengthPercentage | (Keyword<"top"> | Keyword<"bottom"> | Keyword<"sub"> | Keyword<"super"> | Keyword<"baseline"> | Keyword<"text-top"> | Keyword<"text-bottom"> | Keyword<"middle">), Length | (Keyword<"top"> | Keyword<"bottom"> | Keyword<"sub"> | Keyword<"super"> | Keyword<"baseline"> | Keyword<"text-top"> | Keyword<"text-bottom"> | Keyword<"middle">)>;
         readonly visibility: Longhand<Keyword.ToKeywords<"hidden" | "collapse" | "visible">, Keyword.ToKeywords<"hidden" | "collapse" | "visible">>;
         readonly "white-space": Longhand<Keyword.ToKeywords<"nowrap" | "normal" | "pre" | "pre-wrap" | "break-spaces" | "pre-line">, Keyword.ToKeywords<"nowrap" | "normal" | "pre" | "pre-wrap" | "break-spaces" | "pre-line">>;
-        readonly width: Longhand<Percentage | Length | Keyword<"auto">, Length | Percentage.Canonical | Keyword<"auto">>;
+        readonly width: Longhand<LengthPercentage | Keyword<"auto">, LengthPercentage | Keyword<"auto">>;
         readonly "word-spacing": Longhand<Length | Keyword<"normal">, Length>;
     };
     // (undocumented)
@@ -420,6 +421,8 @@ export class Value<T = unknown> implements Functor<T>, Applicative<T>, Monad<T>,
     // (undocumented)
     static of<T>(value: T, source?: Option<Declaration>): Value<T>;
     // (undocumented)
+    resolve<T extends Value_2>(this: Value<T>, resolver?: Resolvable.Resolver<T>): Value<Resolvable.Resolved<T>>;
+    // (undocumented)
     some(predicate: Predicate<T, [source: Option<Declaration>]>): boolean;
     // (undocumented)
     get source(): Option<Declaration>;
diff --git a/packages/alfa-css/src/value/image/gradient/linear/corner.ts b/packages/alfa-css/src/value/image/gradient/linear/corner.ts
index 1b66f2438b..1385a273c8 100644
--- a/packages/alfa-css/src/value/image/gradient/linear/corner.ts
+++ b/packages/alfa-css/src/value/image/gradient/linear/corner.ts
@@ -3,6 +3,7 @@ import { Parser } from "@siteimprove/alfa-parser";
 
 import { type Parser as CSSParser, Token } from "../../../../syntax";
 
+import { Resolvable } from "../../../resolvable";
 import { Value } from "../../../value";
 
 import { Position } from "./position";
@@ -12,7 +13,10 @@ const { map, either, pair, option, right } = Parser;
 /**
  * @internal
  */
-export class Corner extends Value<"corner", false> {
+export class Corner
+  extends Value<"corner", false>
+  implements Resolvable<Corner.Canonical, Corner.Resolver>
+{
   public static of(
     vertical: Position.Vertical,
     horizontal: Position.Horizontal,
diff --git a/packages/alfa-css/src/value/image/gradient/linear/side.ts b/packages/alfa-css/src/value/image/gradient/linear/side.ts
index c15f6588bd..3f0a17a4ec 100644
--- a/packages/alfa-css/src/value/image/gradient/linear/side.ts
+++ b/packages/alfa-css/src/value/image/gradient/linear/side.ts
@@ -3,6 +3,7 @@ import { Parser } from "@siteimprove/alfa-parser";
 
 import { Token } from "../../../../syntax";
 
+import { Resolvable } from "../../../resolvable";
 import { Value } from "../../../value";
 
 import { Position } from "./position";
@@ -12,7 +13,10 @@ const { map, option, right } = Parser;
 /**
  * @internal
  */
-export class Side extends Value<"side", false> {
+export class Side
+  extends Value<"side", false>
+  implements Resolvable<Side.Canonical, Side.Resolver>
+{
   public static of(side: Position.Vertical | Position.Horizontal): Side {
     return new Side(side);
   }
diff --git a/packages/alfa-css/src/value/image/gradient/radial/circle.ts b/packages/alfa-css/src/value/image/gradient/radial/circle.ts
index 96bb450e67..740668573a 100644
--- a/packages/alfa-css/src/value/image/gradient/radial/circle.ts
+++ b/packages/alfa-css/src/value/image/gradient/radial/circle.ts
@@ -5,6 +5,7 @@ import { Parser as CSSParser, Token } from "../../../../syntax";
 
 import { Keyword } from "../../../keyword";
 import { Length } from "../../../numeric";
+import { Resolvable } from "../../../resolvable";
 import { Value } from "../../../value";
 
 /**
@@ -12,10 +13,10 @@ import { Value } from "../../../value";
  *
  * @internal
  */
-export class Circle<R extends Length = Length> extends Value<
-  "circle",
-  Value.HasCalculation<[R]>
-> {
+export class Circle<R extends Length = Length>
+  extends Value<"circle", Value.HasCalculation<[R]>>
+  implements Resolvable<Circle.Canonical, Circle.Resolver>
+{
   public static of<R extends Length>(radius: R): Circle<R> {
     return new Circle(radius);
   }
diff --git a/packages/alfa-css/src/value/image/gradient/radial/extent.ts b/packages/alfa-css/src/value/image/gradient/radial/extent.ts
index 414f4c5427..f1782b0b95 100644
--- a/packages/alfa-css/src/value/image/gradient/radial/extent.ts
+++ b/packages/alfa-css/src/value/image/gradient/radial/extent.ts
@@ -5,6 +5,7 @@ import { Err, Result } from "@siteimprove/alfa-result";
 import { Parser as CSSParser, Token } from "../../../../syntax";
 
 import { Keyword } from "../../../keyword";
+import { Resolvable } from "../../../resolvable";
 import { Value } from "../../../value";
 
 const { map } = Parser;
@@ -12,7 +13,10 @@ const { map } = Parser;
 /**
  * @internal
  */
-export class Extent extends Value<"extent", false> {
+export class Extent
+  extends Value<"extent", false>
+  implements Resolvable<Extent.Canonical, Extent.Resolver>
+{
   public static of(
     shape: Extent.Shape = Extent.Shape.Circle,
     size: Extent.Size = Extent.Size.FarthestCorner,
diff --git a/packages/alfa-css/src/value/image/image.ts b/packages/alfa-css/src/value/image/image.ts
index 37c6167eb3..a5e302341d 100644
--- a/packages/alfa-css/src/value/image/image.ts
+++ b/packages/alfa-css/src/value/image/image.ts
@@ -3,6 +3,7 @@ import { Parser } from "@siteimprove/alfa-parser";
 import { Selective } from "@siteimprove/alfa-selective";
 
 import type { Parser as CSSParser } from "../../syntax";
+import { PartiallyResolvable, Resolvable } from "../resolvable";
 
 import { Value } from "../value";
 
@@ -16,10 +17,12 @@ const { map, either } = Parser;
  *
  * @public
  */
-export class Image<I extends URL | Gradient = URL | Gradient> extends Value<
-  "image",
-  Value.HasCalculation<[I]>
-> {
+export class Image<I extends URL | Gradient = URL | Gradient>
+  extends Value<"image", Value.HasCalculation<[I]>>
+  implements
+    Resolvable<Image.Canonical, Image.Resolver>,
+    PartiallyResolvable<Image.PartiallyResolved, Image.PartialResolver>
+{
   public static of<I extends URL | Gradient>(image: I): Image<I> {
     return new Image(image);
   }
@@ -39,6 +42,17 @@ export class Image<I extends URL | Gradient = URL | Gradient> extends Value<
     return new Image(this._image.resolve(resolver));
   }
 
+  public partiallyResolve(
+    resolver: Image.PartialResolver,
+  ): Image.PartiallyResolved {
+    return Image.of(
+      Selective.of(this._image)
+        .if(URL.isURL, (url) => url.resolve())
+        .else((gradient) => gradient.partiallyResolve(resolver))
+        .get(),
+    );
+  }
+
   public equals(value: unknown): value is this {
     return value instanceof Image && value._image.equals(this._image);
   }
@@ -77,18 +91,6 @@ export namespace Image {
 
   export type PartialResolver = URL.Resolver & Gradient.PartialResolver;
 
-  export function partiallyResolve(
-    resolver: PartialResolver,
-  ): (value: Image) => PartiallyResolved {
-    return (value) =>
-      Image.of(
-        Selective.of(value.image)
-          .if(URL.isURL, (url) => url.resolve())
-          .else((gradient) => gradient.partiallyResolve(resolver))
-          .get(),
-      );
-  }
-
   export function isImage<I extends URL | Gradient>(
     value: unknown,
   ): value is Image<I> {
diff --git a/packages/alfa-css/src/value/image/url.ts b/packages/alfa-css/src/value/image/url.ts
index 7fa6bf4fbf..a0367f9a3d 100644
--- a/packages/alfa-css/src/value/image/url.ts
+++ b/packages/alfa-css/src/value/image/url.ts
@@ -2,6 +2,7 @@ import { Hash } from "@siteimprove/alfa-hash";
 import { Parser } from "@siteimprove/alfa-parser";
 
 import { Function, type Parser as CSSParser, Token } from "../../syntax";
+import { Resolvable } from "../resolvable";
 
 import { Value } from "../value";
 
@@ -12,7 +13,7 @@ const { map, either } = Parser;
  *
  * @public
  */
-export class URL extends Value<"url", false> {
+export class URL extends Value<"url", false> implements Resolvable<URL, never> {
   public static of(url: string): URL {
     return new URL(url);
   }
diff --git a/packages/alfa-css/src/value/index.ts b/packages/alfa-css/src/value/index.ts
index 19cc17ad11..dc5541133e 100644
--- a/packages/alfa-css/src/value/index.ts
+++ b/packages/alfa-css/src/value/index.ts
@@ -5,6 +5,7 @@ export * from "./image";
 export * from "./keyword";
 export * from "./numeric";
 export * from "./position";
+export * from "./resolvable";
 export * from "./shadow";
 export * from "./shape";
 export * from "./string";
diff --git a/packages/alfa-css/src/value/numeric/percentage.ts b/packages/alfa-css/src/value/numeric/percentage.ts
index 31f9a21d60..2509bece6a 100644
--- a/packages/alfa-css/src/value/numeric/percentage.ts
+++ b/packages/alfa-css/src/value/numeric/percentage.ts
@@ -52,7 +52,7 @@ export type Percentage<H extends BaseNumeric.Type = BaseNumeric.Type> =
  * @public
  */
 export namespace Percentage {
-  export type Canonical = Fixed;
+  export type Canonical = Fixed<"percentage">;
 
   export type PartiallyResolved<H extends BaseNumeric.Type> = Fixed<H>;
 
@@ -80,13 +80,13 @@ export namespace Percentage {
       return true;
     }
 
-    public resolve(): Canonical;
+    public resolve(): Fixed<H>;
 
     public resolve<T extends Canonicals[H]>(resolver: Resolver<H>): T;
 
     public resolve<T extends Canonicals[H]>(
       resolver?: Resolver<H>,
-    ): Canonical | T {
+    ): Fixed<H> | T {
       const percentage = Fixed.of<H>(
         this._math
           .resolve()
diff --git a/packages/alfa-css/src/value/shape/rectangle.ts b/packages/alfa-css/src/value/shape/rectangle.ts
index 0cc0ae7ace..e339a2e269 100644
--- a/packages/alfa-css/src/value/shape/rectangle.ts
+++ b/packages/alfa-css/src/value/shape/rectangle.ts
@@ -5,6 +5,7 @@ import { Comma, Function, type Parser as CSSParser, Token } from "../../syntax";
 
 import { Keyword } from "../keyword";
 import { Length } from "../numeric";
+import { Resolvable } from "../resolvable";
 import { Value } from "../value";
 
 import { BasicShape } from "./basic-shape";
@@ -18,8 +19,11 @@ const { either, map, option, separatedList } = Parser;
  * @deprecated Deprecated as of CSS Masking Module Level 1
  */
 export class Rectangle<
-  O extends Length | Rectangle.Auto = Length | Rectangle.Auto,
-> extends BasicShape<"rectangle", Value.HasCalculation<[O, O, O, O]>> {
+    O extends Length | Rectangle.Auto = Length | Rectangle.Auto,
+  >
+  extends BasicShape<"rectangle", Value.HasCalculation<[O, O, O, O]>>
+  implements Resolvable<Rectangle.Canonical, Rectangle.Resolver>
+{
   public static of<O extends Length | Rectangle.Auto = Length | Rectangle.Auto>(
     top: O,
     right: O,
diff --git a/packages/alfa-css/src/value/shape/shape.ts b/packages/alfa-css/src/value/shape/shape.ts
index ee79c58533..b1024da7a8 100644
--- a/packages/alfa-css/src/value/shape/shape.ts
+++ b/packages/alfa-css/src/value/shape/shape.ts
@@ -3,6 +3,7 @@ import { Parser } from "@siteimprove/alfa-parser";
 import { Err, Result } from "@siteimprove/alfa-result";
 import { Selective } from "@siteimprove/alfa-selective";
 import { Slice } from "@siteimprove/alfa-slice";
+import { PartiallyResolvable, Resolvable } from "../resolvable";
 
 import { Value } from "../value";
 import { type Parser as CSSParser, Token } from "../../syntax";
@@ -22,9 +23,14 @@ const { either } = Parser;
  * @public
  */
 export class Shape<
-  S extends Shape.Basic = Shape.Basic,
-  B extends Box.Geometry = Box.Geometry,
-> extends Value<"shape", Value.HasCalculation<[S]>> {
+    S extends Shape.Basic = Shape.Basic,
+    B extends Box.Geometry = Box.Geometry,
+  >
+  extends Value<"shape", Value.HasCalculation<[S]>>
+  implements
+    Resolvable<Shape.Canonical, Shape.Resolver>,
+    PartiallyResolvable<Shape.PartiallyResolved, Shape.PartialResolver>
+{
   public static of<
     S extends Shape.Basic = Shape.Basic,
     B extends Box.Geometry = Box.Geometry,
@@ -53,6 +59,15 @@ export class Shape<
     return new Shape(this._shape.resolve(resolver), this._box);
   }
 
+  public partiallyResolve(
+    resolver: Shape.PartialResolver,
+  ): Shape.PartiallyResolved {
+    return Shape.of(
+      Shape.Basic.partiallyResolve(resolver)(this._shape),
+      this._box,
+    );
+  }
+
   public equals(value: Shape): boolean;
 
   public equals(value: unknown): value is this;
@@ -93,7 +108,7 @@ export namespace Shape {
    */
   export type Basic = Circle | Ellipse | Inset | Polygon | Rectangle;
 
-  namespace Basic {
+  export namespace Basic {
     export type Canonical =
       | Circle.Canonical
       | Ellipse.Canonical
@@ -161,13 +176,6 @@ export namespace Shape {
 
   export type PartialResolver = Basic.PartialResolver;
 
-  export function partiallyResolve(
-    resolver: PartialResolver,
-  ): (value: Shape) => PartiallyResolved {
-    return (value) =>
-      Shape.of(Basic.partiallyResolve(resolver)(value.shape), value.box);
-  }
-
   /**
    * @remarks
    * This does not parse the deprecated `rect()` shape.
diff --git a/packages/alfa-style/src/property/background-color.ts b/packages/alfa-style/src/property/background-color.ts
index a590505a5c..4922f696cd 100644
--- a/packages/alfa-style/src/property/background-color.ts
+++ b/packages/alfa-style/src/property/background-color.ts
@@ -10,6 +10,9 @@ export type Specified = Color;
 type Computed = Color.Canonical;
 
 /**
+ * @remarks
+ * This is used by the shorthand parser for background.
+ *
  * @internal
  */
 export const parse = Color.parse;
@@ -26,5 +29,5 @@ export default Longhand.of<Specified, Computed>(
     Percentage.of(0),
   ),
   parse,
-  (value) => value.map((color) => color.resolve()),
+  (value) => value.resolve(),
 );
diff --git a/packages/alfa-style/src/property/background-image.ts b/packages/alfa-style/src/property/background-image.ts
index a6eb6d1079..9349fef7fe 100644
--- a/packages/alfa-style/src/property/background-image.ts
+++ b/packages/alfa-style/src/property/background-image.ts
@@ -41,7 +41,9 @@ export default Longhand.of<Specified, Computed>(
     value.map((images) =>
       images.map((image) =>
         Selective.of(image)
-          .if(Image.isImage, Image.partiallyResolve(Resolver.length(style)))
+          .if(Image.isImage, (image) =>
+            image.partiallyResolve(Resolver.length(style)),
+          )
           .get(),
       ),
     ),
diff --git a/packages/alfa-style/src/property/border-image-outset.ts b/packages/alfa-style/src/property/border-image-outset.ts
index b2f1b184ad..15643c8ad2 100644
--- a/packages/alfa-style/src/property/border-image-outset.ts
+++ b/packages/alfa-style/src/property/border-image-outset.ts
@@ -63,15 +63,5 @@ export const parse = map(
 export default Longhand.of<Specified, Computed>(
   Tuple.of(Number.of(0), Number.of(0), Number.of(0), Number.of(0)),
   parse,
-  (value, style) =>
-    value.map(({ values: [t, r, b, l] }) => {
-      const resolver = resolve(style);
-      return Tuple.of(resolver(t), resolver(r), resolver(b), resolver(l));
-    }),
+  (value, style) => value.resolve(Resolver.length(style)),
 );
-
-function resolve(style: Style): (specified: Specified.Item) => Computed.Item {
-  const resolver = Resolver.length(style);
-  return (specified) =>
-    Length.isLength(specified) ? specified.resolve(resolver) : specified;
-}
diff --git a/packages/alfa-style/src/property/border-image-slice.ts b/packages/alfa-style/src/property/border-image-slice.ts
index a16c2fdb7f..33b44493ca 100644
--- a/packages/alfa-style/src/property/border-image-slice.ts
+++ b/packages/alfa-style/src/property/border-image-slice.ts
@@ -23,9 +23,9 @@ type ImageSlice<T extends Value> = NoFill<T> | WithFill<T>;
 /**
  * @internal
  */
-export type Specified = ImageSlice<Number | Percentage>;
+export type Specified = ImageSlice<Number | Percentage<"percentage">>;
 
-type Computed = Specified;
+type Computed = ImageSlice<Number.Canonical | Percentage.Canonical>;
 
 const parseItem = filter(
   either(Number.parse, Percentage.parse),
@@ -111,5 +111,5 @@ export default Longhand.of<Specified, Computed>(
     Percentage.of(1),
   ),
   parse,
-  (value) => value,
+  (value) => value.resolve(),
 );
diff --git a/packages/alfa-style/src/property/border-image-source.ts b/packages/alfa-style/src/property/border-image-source.ts
index 41376a77a2..3153fe6834 100644
--- a/packages/alfa-style/src/property/border-image-source.ts
+++ b/packages/alfa-style/src/property/border-image-source.ts
@@ -29,7 +29,9 @@ export default Longhand.of<Specified, Computed>(
   (value, style) =>
     value.map((image) =>
       Selective.of(image)
-        .if(Image.isImage, Image.partiallyResolve(Resolver.length(style)))
+        .if(Image.isImage, (image) =>
+          image.partiallyResolve(Resolver.length(style)),
+        )
         .get(),
     ),
 );
diff --git a/packages/alfa-style/src/property/border-top-color.ts b/packages/alfa-style/src/property/border-top-color.ts
index 48767ccfc2..27d9c1c40c 100644
--- a/packages/alfa-style/src/property/border-top-color.ts
+++ b/packages/alfa-style/src/property/border-top-color.ts
@@ -10,6 +10,9 @@ export type Specified = Color;
 type Computed = Color.Canonical;
 
 /**
+ * @remarks
+ * This is used by the shorthand
+ *
  * @internal
  */
 export const parse = Color.parse;
@@ -19,5 +22,5 @@ export const parse = Color.parse;
  * @internal
  */
 export default Longhand.of<Specified, Computed>(Color.current, parse, (value) =>
-  value.map((color) => color.resolve()),
+  value.resolve(),
 );
diff --git a/packages/alfa-style/src/property/border-top-left-radius.ts b/packages/alfa-style/src/property/border-top-left-radius.ts
index 8829347e9d..e2e71e4def 100644
--- a/packages/alfa-style/src/property/border-top-left-radius.ts
+++ b/packages/alfa-style/src/property/border-top-left-radius.ts
@@ -10,13 +10,6 @@ type Specified = Tuple<
   [horizontal: LengthPercentage, vertical: LengthPercentage]
 >;
 
-/**
- * @remarks
- * TODO: percentages resolve relative to the dimensions of the containing block,
- *       which we do not handle.
- *       This results in length-percentage calculations leaking to computed
- *       values, which is a bit annoying.
- */
 type Computed = Tuple<
   [
     horizontal: LengthPercentage.PartiallyResolved,
@@ -42,8 +35,6 @@ export default Longhand.of<Specified, Computed>(
   parse,
   (value, style) =>
     value.map(({ values: [h, v] }) =>
-      // Percentages are relative to the size of the border box, which we don't
-      // really handle currently.
       Tuple.of(
         LengthPercentage.partiallyResolve(Resolver.length(style))(h),
         LengthPercentage.partiallyResolve(Resolver.length(style))(v),
diff --git a/packages/alfa-style/src/property/box-shadow.ts b/packages/alfa-style/src/property/box-shadow.ts
index 8a64060213..ed391dd791 100644
--- a/packages/alfa-style/src/property/box-shadow.ts
+++ b/packages/alfa-style/src/property/box-shadow.ts
@@ -19,6 +19,5 @@ const parseList = List.parseCommaSeparated(Shadow.parse());
 export default Longhand.of<Specified, Computed>(
   Keyword.of("none"),
   either(Keyword.parse("none"), parseList),
-  (boxShadow, style) =>
-    boxShadow.map((value) => value.resolve(Resolver.length(style))),
+  (value, style) => value.resolve(Resolver.length(style)),
 );
diff --git a/packages/alfa-style/src/property/color.ts b/packages/alfa-style/src/property/color.ts
index 20f119c1c4..c4c81ab321 100644
--- a/packages/alfa-style/src/property/color.ts
+++ b/packages/alfa-style/src/property/color.ts
@@ -13,7 +13,7 @@ type Computed = Color.Canonical;
 export default Longhand.of<Specified, Computed>(
   Color.system("canvastext"),
   Color.parse,
-  (value) => value.map((color) => color.resolve()),
+  (value) => value.resolve(),
   {
     inherits: true,
   },
diff --git a/packages/alfa-style/src/property/cursor.ts b/packages/alfa-style/src/property/cursor.ts
index c62fdb7b03..7d5f562246 100644
--- a/packages/alfa-style/src/property/cursor.ts
+++ b/packages/alfa-style/src/property/cursor.ts
@@ -57,7 +57,11 @@ namespace Specified {
 
 type Specified = Tuple<[List<Specified.Custom>, Specified.Builtin]>;
 
-type Computed = Specified;
+type Computed = Tuple<[List<Computed.Custom>, Specified.Builtin]>;
+
+namespace Computed {
+  export type Custom = URL | Tuple<[URL, Number.Canonical, Number.Canonical]>;
+}
 
 const parseBuiltin = Keyword.parse(
   "auto",
@@ -124,6 +128,6 @@ const parse = map(
 export default Longhand.of<Specified, Computed>(
   Tuple.of(List.of([], ","), Keyword.of("auto")),
   parse,
-  (value) => value,
+  (value) => value.resolve(),
   { inherits: true },
 );
diff --git a/packages/alfa-style/src/property/outline-color.ts b/packages/alfa-style/src/property/outline-color.ts
index d66468a332..2161b8ea7f 100644
--- a/packages/alfa-style/src/property/outline-color.ts
+++ b/packages/alfa-style/src/property/outline-color.ts
@@ -13,12 +13,5 @@ type Computed = Color.Canonical | Keyword<"invert">;
 export default Longhand.of<Specified, Computed>(
   Keyword.of("invert"),
   Color.parse,
-  (outlineColor) =>
-    outlineColor.map((color) => {
-      if (color.type === "keyword" && color.value === "invert") {
-        return color;
-      }
-
-      return color.resolve();
-    }),
+  (value) => value.resolve(),
 );
diff --git a/packages/alfa-style/src/property/outline-offset.ts b/packages/alfa-style/src/property/outline-offset.ts
index 4760ed5635..c55ec273cd 100644
--- a/packages/alfa-style/src/property/outline-offset.ts
+++ b/packages/alfa-style/src/property/outline-offset.ts
@@ -13,6 +13,5 @@ type Computed = Length.Canonical;
 export default Longhand.of<Specified, Computed>(
   Length.of(0, "px"),
   Length.parse,
-  (value, style) =>
-    value.map((offset) => offset.resolve(Resolver.length(style))),
+  (value, style) => value.resolve(Resolver.length(style)),
 );
diff --git a/packages/alfa-style/src/property/text-decoration-color.ts b/packages/alfa-style/src/property/text-decoration-color.ts
index 9e9bb5d530..757724ffc4 100644
--- a/packages/alfa-style/src/property/text-decoration-color.ts
+++ b/packages/alfa-style/src/property/text-decoration-color.ts
@@ -6,8 +6,6 @@ type Specified = Color;
 
 type Computed = Color.Canonical;
 
-const parse = Color.parse;
-
 /**
  * {@link https://developer.mozilla.org/en-US/docs/Web/CSS/text-decoration-color}
  *
@@ -15,6 +13,6 @@ const parse = Color.parse;
  */
 export default Longhand.of<Specified, Computed>(
   Color.current,
-  parse,
-  (textDecorationColor) => textDecorationColor.map((color) => color.resolve()),
+  Color.parse,
+  (value) => value.resolve(),
 );
diff --git a/packages/alfa-style/src/property/text-decoration-thickness.ts b/packages/alfa-style/src/property/text-decoration-thickness.ts
index 53baf95805..23759dd3a1 100644
--- a/packages/alfa-style/src/property/text-decoration-thickness.ts
+++ b/packages/alfa-style/src/property/text-decoration-thickness.ts
@@ -1,13 +1,10 @@
 import { Keyword, LengthPercentage, type Token } from "@siteimprove/alfa-css";
 import { Parser } from "@siteimprove/alfa-parser";
-import { Selective } from "@siteimprove/alfa-selective";
 import type { Slice } from "@siteimprove/alfa-slice";
 
 import { Longhand } from "../longhand";
 import { Resolver } from "../resolver";
 
-import type { Computed as FontSize } from "./font-size";
-
 const { either } = Parser;
 
 type Specified = LengthPercentage | Keyword<"auto"> | Keyword<"from-font">;
@@ -22,24 +19,16 @@ const parse = either<Slice<Token>, Specified, string>(
   LengthPercentage.parse,
 );
 
+const longhand: Longhand<Specified, Computed> = Longhand.of(
+  Keyword.of("auto"),
+  parse,
+  (value, style) =>
+    value.resolve(
+      Resolver.lengthPercentage(style.computed("font-size").value, style),
+    ),
+);
 /**
  * {@link https://developer.mozilla.org/en-US/docs/Web/CSS/text-decoration-thickness}
  * @internal
  */
-export default Longhand.of<Specified, Computed>(
-  Keyword.of("auto"),
-  parse,
-  (thickness, style) =>
-    thickness.map((value) => {
-      // We need the type assertion to help TS break a circular type reference:
-      // this -> style.computed -> Longhands.Name -> Longhands.longhands -> this.
-      const fontSize = style.computed("font-size").value as FontSize;
-
-      return Selective.of(value)
-        .if(
-          LengthPercentage.isLengthPercentage,
-          LengthPercentage.resolve(Resolver.lengthPercentage(fontSize, style)),
-        )
-        .get();
-    }),
-);
+export default longhand;
diff --git a/packages/alfa-style/src/property/text-indent.ts b/packages/alfa-style/src/property/text-indent.ts
index cdaede903e..cd1e1b4ae2 100644
--- a/packages/alfa-style/src/property/text-indent.ts
+++ b/packages/alfa-style/src/property/text-indent.ts
@@ -5,14 +5,6 @@ import { Resolver } from "../resolver";
 
 type Specified = LengthPercentage;
 
-/**
- * @remarks
- * TODO: percentages resolve relative to the dimensions of the containing block,
- *       which we do not handle.
- *       This results in length-percentage calculations leaking to computed
- *       values, which is a bit annoying.
- *
- */
 type Computed = LengthPercentage.PartiallyResolved;
 
 /**
diff --git a/packages/alfa-style/src/property/text-shadow.ts b/packages/alfa-style/src/property/text-shadow.ts
index c0feafa893..4549037d75 100644
--- a/packages/alfa-style/src/property/text-shadow.ts
+++ b/packages/alfa-style/src/property/text-shadow.ts
@@ -21,7 +21,6 @@ const parseList = List.parseCommaSeparated(
 export default Longhand.of<Specified, Computed>(
   Keyword.of("none"),
   either(Keyword.parse("none"), parseList),
-  (textShadow, style) =>
-    textShadow.map((value) => value.resolve(Resolver.length(style))),
+  (value, style) => value.resolve(Resolver.length(style)),
   { inherits: true },
 );
diff --git a/packages/alfa-style/src/property/width.ts b/packages/alfa-style/src/property/width.ts
index 344d179064..1302e92caf 100644
--- a/packages/alfa-style/src/property/width.ts
+++ b/packages/alfa-style/src/property/width.ts
@@ -1,19 +1,17 @@
-import { Keyword, Length, Percentage } from "@siteimprove/alfa-css";
+import { Keyword, LengthPercentage } from "@siteimprove/alfa-css";
 import { Parser } from "@siteimprove/alfa-parser";
+import { Selective } from "@siteimprove/alfa-selective";
 
 import { Longhand } from "../longhand";
 import { Resolver } from "../resolver";
 
 const { either } = Parser;
 
-type Specified = Keyword<"auto"> | Length | Percentage;
+type Specified = Keyword<"auto"> | LengthPercentage;
 
-type Computed = Keyword<"auto"> | Length.Canonical | Percentage.Canonical;
+type Computed = Keyword<"auto"> | LengthPercentage.PartiallyResolved;
 
-const parse = either(
-  Keyword.parse("auto"),
-  either(Length.parse, Percentage.parse),
-);
+const parse = either(Keyword.parse("auto"), LengthPercentage.parse);
 
 /**
  * {@link https://developer.mozilla.org/en-US/docs/Web/CSS/width}
@@ -23,15 +21,12 @@ export default Longhand.of<Specified, Computed>(
   Keyword.of("auto"),
   parse,
   (width, style) =>
-    width.map((width) => {
-      switch (width.type) {
-        case "keyword":
-          return width;
-        case "percentage":
-          return width.resolve();
-
-        case "length":
-          return width.resolve(Resolver.length(style));
-      }
-    }),
+    width.map((width) =>
+      Selective.of(width)
+        .if(
+          LengthPercentage.isLengthPercentage,
+          LengthPercentage.partiallyResolve(Resolver.length(style)),
+        )
+        .get(),
+    ),
 );
diff --git a/packages/alfa-style/src/property/word-spacing.ts b/packages/alfa-style/src/property/word-spacing.ts
index 35b3a41bf0..fccdbd8e45 100644
--- a/packages/alfa-style/src/property/word-spacing.ts
+++ b/packages/alfa-style/src/property/word-spacing.ts
@@ -1,7 +1,6 @@
 import { Keyword } from "@siteimprove/alfa-css";
 import { Length } from "@siteimprove/alfa-css/src/value/numeric";
 import { Parser } from "@siteimprove/alfa-parser";
-import { Selective } from "@siteimprove/alfa-selective";
 
 import { Longhand } from "../longhand";
 import { Resolver } from "../resolver";
@@ -21,15 +20,12 @@ const parse = either(Keyword.parse("normal"), Length.parse);
 export default Longhand.of<Specified, Computed>(
   Length.of(0, "px"),
   parse,
-  (wordSpacing, style) =>
-    wordSpacing.map((wordSpacing) =>
-      Selective.of(wordSpacing)
-        .if(Length.isLength, (spacing) =>
-          spacing.resolve(Resolver.length(style)),
-        )
-        .else(() => Length.of(0, "px"))
-        .get(),
-    ),
+  (value, style) =>
+    value
+      .resolve(Resolver.length(style))
+      .map((wordSpacing) =>
+        Keyword.isKeyword(wordSpacing) ? Length.of(0, "px") : wordSpacing,
+      ),
   {
     inherits: true,
   },
diff --git a/packages/alfa-style/src/value.ts b/packages/alfa-style/src/value.ts
index 87cb46900b..4094f4fe1e 100644
--- a/packages/alfa-style/src/value.ts
+++ b/packages/alfa-style/src/value.ts
@@ -1,4 +1,5 @@
 import { Applicative } from "@siteimprove/alfa-applicative";
+import type { Resolvable, Value as CSSValue } from "@siteimprove/alfa-css";
 import { Declaration } from "@siteimprove/alfa-dom";
 import { Equatable } from "@siteimprove/alfa-equatable";
 import { Functor } from "@siteimprove/alfa-functor";
@@ -46,6 +47,16 @@ export class Value<T = unknown>
     return new Value(mapper(this._value, this._source), this._source);
   }
 
+  public resolve<T extends CSSValue>(
+    this: Value<T>,
+    resolver?: Resolvable.Resolver<T>,
+  ): Value<Resolvable.Resolved<T>> {
+    return new Value(
+      this._value.resolve(resolver) as Resolvable.Resolved<T>,
+      this._source,
+    );
+  }
+
   public apply<U>(mapper: Value<Mapper<T, U>>): Value<U> {
     return mapper.map((mapper) => mapper(this._value));
   }