How to alter the look of + and - quantity

I am using Ajax to update quantities of the product. How can I alter the appearance of the + and - please? At the moment they don't appear in line with the quantity; the - is well below the quantity. They are both very small too. Any help would be welcome. Thanks

Thanks for the reply. Could you tell me which section of the css I need to edit please?

Hi there,

You should use the "inspect element" function of your browser to find the classes related.
It's all explained in the documentation's link Jerome gave you , and it could help you a lot if you want to customize your css in the future.
In this case and according to the demo website, you have to add css to this class: hikashop_product_stock td a.
You can do something like this:

.hikashop_product_stock td a{
  color:red;
  background: youimage.png;
}