I know this topic has been debated before but none of the listed solutions seems to work for me.
I have removed easily the shadow in the catalog page but in the simple product page, the featured image of the product doesn't loose its shadow.
Cheching it with Firebug, it seems that the CSS for that specific shadow is managed by a CSS in the Woocommerce/assets folder, not in the style.css file of the neighborhood theme.
I don't want to touch any file from the Woocommerce folders, because in any update they will be overwritten, so, is there a way to tweak the shadow in the single product page?
Thank you very much for your answer.