What part of +/- buttons exactly?
This is the whole chunk, similar to what Tom posted here:
.do-quantity-buttons form .quantity:not(.buttons-added):not(.hidden)::after,
.do-quantity-buttons form .quantity:not(.buttons-added):not(.hidden)::before,
.woocommerce form .quantity.buttons-added .minus,
.woocommerce form .quantity.buttons-added .plus,
.woocommerce form .quantity.buttons-added .qty
Minus, plus and qty are doing their thing fine, it’s the first two selectors that I’ve no clue what they’re applied to.
Part of that script adds the button-added class.
However, if the user browser is blocking JS then the button-added class is not added. And then those classes kick in to add the + and – symbols as CSS pseudo elements.