AngleSharp by Florian Rappl

<PackageReference Include="AngleSharp" Version="0.8.0" />

.NET API 1,171,968 bytes

CssMarginTopProperty

sealed class CssMarginTopProperty : CssMarginPartProperty, ICssMarginTopProperty, ICssProperty

Information can be found on MDN: https://developer.mozilla.org/en-US/docs/Web/CSS/margin-top

public Length? Top { get; }