If I have for example 1-5 items in cart the price is regular, but if you buy more than 6 then an automatic discount is applied. that also changes my font and the size of the new price/old price.
Is there a code or something how to overwrite or control it ?
To apply a discount when customers add more than 6 items to their cart and customize the display of the new price, you can use custom JavaScript and CSS:
JavaScript: Check the cart quantity and apply a discount if there are 6+ items.
CSS: Control the styling of the old and new price after the discount is applied.