.Page-Step2 .One-Field.Payment-Information-BrazilPersonalVAT input {
    width: 95%!important;
} 
.One-Field.Payment-Information-BrazilPersonalVAT {
    width: 100%;
}

@media (max-width: 768px){
    .One-Field.Payment-Information-BrazilPersonalVAT input {
        width: 85%;
    }
}