Hi,
By default stock quantity for product is "unlimited" and if the stock is "unlimited", it is not show in the product page.
www.hikashop.com/en/support/documentatio...form.html#additional
Quantity : The quantity in stock for the product. Unless the quantity is unlimited, people won't be able to buy over the stock and each time an order is made with this product, the stock will be adjusted. When an order is cancelled (there is an option in the configuration page to set the statuses involved), the stock will be restored.
About CSS, you have to edit the front end CSS file.
www.hikashop.com/en/support/documentatio...shop-config.html#css
For the product picture, you can change the CSS or modify the "product show" ("product show_default" since HikaShop 1.5.6) view.
Regards,