ATC and Quantity button - next to each other and same size

[TBS2022]

Hello

I have added this code in order to move my ATC button next to the quantity selector

.btn--full { width: calc(100% - 150px) !important; margin-top: -100px; margin-left: 150px; }

However the 2 buttons are not the right size - how can I make them equal?

I am using the Impulse them

webpage: https://39e9ca.myshopify.com/

password: riacia

Thanks