AngleSharp by Florian Rappl

<PackageReference Include="AngleSharp" Version="0.3.0" />

 CSSRule

public abstract class CSSRule : ICSSObject
Represents a CSS rule.
namespace AngleSharp.DOM.Css { [DOM("CSSRule")] public abstract class CSSRule : ICSSObject { protected CssRuleType _type; protected CSSStyleSheet _parent; protected CSSRule _parentRule; [DOM("cssText")] public string CssText { get { return ToCss(); } } [DOM("parentRule")] public CSSRule ParentRule { get { return _parentRule; } internal set { _parentRule = value; } } [DOM("parentStyleSheet")] public CSSStyleSheet ParentStyleSheet { get { return _parent; } internal set { _parent = value; } } [DOM("type")] public CssRuleType Type { get { return _type; } } internal CSSRule() { _type = CssRuleType.Unknown; } public abstract string ToCss(); } }