AngleSharp by Florian Rappl

<PackageReference Include="AngleSharp" Version="0.8.1" />

.NET API 1,172,480 bytes

 CssColumnSpanProperty

sealed class CssColumnSpanProperty : CssProperty, ICssColumnSpanProperty, ICssProperty
More information available at: https://developer.mozilla.org/en-US/docs/Web/CSS/column-span
public bool IsSpanning { get; }

Gets if the element should span across all columns.

public void SetSpanning(bool span)

Sets if content in the normal flow that appears before the element is automatically balanced across all columns before the element appears. The element establishes a new block formatting context.