private function buildOffset(array &$classes, string $sizeSuffix): void
    {
        if ($this->offset === null) {
            return;
        }

        if (is_int($this->offset)) {
            $classes[] = 'offset' . $sizeSuffix . '-' . $this->offset;
        } elseif (strlen($this->offset)) {
            $classes[] = $this->offset;
        }
    }