Hello,
1. In our theme, the quantity, add to cart and buy now buttons are already inline, they fall under each other only if there is not enough horizontal space for them. This is done so that they do not go beyond the edge of the screen and are always available for clicking: https://gyazo.com/34a26cdd00681a1762084b2f4d4bdf97
With the help of custom code, you can turn off the wrapping of these elements so that they are always in one row, but in this case, on the smallest mobile screens, the buttons may go beyond the edge of the screen: https://gyazo.com/42da4d055125db0fc8b7560f14b9bddd
2. If you are satisfied with this position of the buttons on mobile, use the following custom code to disable the wrap for the buttons of simple and variable products:
/* simple product */
.summary-inner > .cart:not(.variations_form) {
flex-wrap: nowrap;
}
/* variable product */
.summary-inner .variations_form .woocommerce-variation-add-to-cart {
flex-wrap: nowrap;
}
Kind Regards