AngleSharp by Florian Rappl

<PackageReference Include="AngleSharp" Version="0.5.0" />

 CSSCalcValue

public abstract class CSSCalcValue : CSSValue
Gets a computed value. Could also be just an absolute or relative value.
public static readonly CSSCalcValue Center

Gets a value that computes to 50% of the original dimension.

public static readonly CSSCalcValue Full

Gets a value that computes to 100% of the original dimension.

public static readonly CSSCalcValue Zero

Gets a value that computes to 0.

protected CSSCalcValue()

public static CSSCalcValue FromLength(Length length)

public static CSSCalcValue FromPercent(Percent percent)

public abstract float ToPixel()