layout checkout

Hi i’m trying to put the code bellow in the style.css of the child-theme, to chage the woocommerce-mod.css, but it seems to do no change, the layout in the checkout is bat on the mobile

@media only screen and (max-width: 767px){
.responsive #top .col2-set .col-1, .responsive #top .col2-set .col-2 { width:100% !important;}
#top #payment ul.payment_methods li{padding:6px !important;}
#top #payment div.payment_box{ width:100% !important; padding:1em 6px !important; max-height: 610px !important;}
}