.woocommerce form.woocommerce-form-register .wcrf-phone-row {
  clear: both;
}

.woocommerce form.woocommerce-form-register button[name="register"][disabled] {
  cursor: not-allowed;
  opacity: .5;
}

@media (max-width: 600px) {
  .woocommerce form.woocommerce-form-register .wcrf-phone-country,
  .woocommerce form.woocommerce-form-register .wcrf-phone-number {
    float: none;
    width: 100%;
  }
}