.phonefield{
    clear: both;
}
.phonefield select[name="phone_0"], .phonefield select[name="mobile_0"]{
    width: 25%;
    float: left;
}
.phonefield input[name="phone_1"], .phonefield input[name="mobile_1"]{
    width: 75% !important;
    box-sizing: border-box;
    float: left;
    height: auto;
}
@media(max-width: 767px){
    .form-horizontal label{
        width: 100%;
        text-align: center;
    }
    .phonefield select[name="phone_0"], .phonefield select[name="mobile_0"]{
        width: 100%;
    }
    .phonefield input[name="phone_1"], .phonefield input[name="mobile_1"]{
        width: 100% !important;
    }
}