AngleSharp by Florian Rappl

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

.NET API 681,472 bytes

 CSSBorderCollapseProperty

public sealed class CSSBorderCollapseProperty : CSSProperty
Information can be found on MDN: https://developer.mozilla.org/en-US/docs/Web/CSS/border-collapse
public bool IsSeparated { get; }

Gets the use of the separated-border table rendering model. Otherwise the collapsed-border table rendering model is used.