private function placeholderSVG($config): string
    {
        $width = $config['width'];
        $height = $config['height'];
        $color = $config['color'] ?? 'transparent';

        return 'data:image/svg+xml;charset=utf-8,' . rawurlencode("<svg xmlns='http://www.w3.org/2000/svg' width='$width' height='$height' style='background:$color'/>");
    }