/// <summary>
/// Given a string quad, flips the left and right values.
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
static CssValue flipQuad(CssValue value)
{
if (!value.IsNumber)
{
var parts = value.ToString().Split(' ');
if (parts.Length == 4)
{
return($"{parts[0]} {parts[3]} { parts[2]} { parts[1]}");
}
}
return(value);
}