Quantity field not visible

The quantity selection field does not have enough space to see the number written. I have tried to modify font sizes, open the page margins, among other options but it has not been possible to solve the problem, it is happening on PC and mobile What should I do? you can check the error when trying to quote any product, for example this one: https://ambientewellness.cl/producto/aqualife-5/

The page I need help with: [log in to see the link]