class CustomFlowLayout: UICollectionViewFlowLayout {

    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
        guard let collectionView = collectionView else {
            return nil
        }

        var layoutAttributes = super.layoutAttributesForElements(in: rect)

        // Adjust header position
        layoutAttributes?.forEach { attributes in
            if attributes.representedElementKind == UICollectionView.elementKindSectionHeader {
                let contentOffsetY = collectionView.contentOffset.y
                let headerHeight = attributes.frame.size.height
                var origin = attributes.frame.origin

                // Pin header to top
                origin.y = min(max(contentOffsetY, 0), headerHeight)

                attributes.frame = CGRect(origin: origin, size: attributes.frame.size)
            }
        }

        return layoutAttributes
    }

    override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool {
        return true // Invalidate layout when bounds change
    }
}