Hello,
Please add this code to the Theme Settings > Custom CSS > Global:
body .single_add_to_cart_button {
min-height: 50px;
min-width: 200px;
font-size: 16px;
}
You can change 200px for the value as per your needs.
In case the Add to cart height is changed, it may be necessary to increase the quantity height, you can do that with this code:
.woocommerce-variation-add-to-cart div.quantity input[type="button"],
.woocommerce-variation-add-to-cart div.quantity :is(input[type="number"],input[type="text"]) {
height: 50px;
}
If you have any questions please feel free to contact us.
Best Regards