如何在CSS中将RadioButton图标样式设置为空(在Flex 3中)？

input[type="radio"] {
  display: none;
}

input[type="radio"] + label::before {
  content: "";
  display: inline-block;
  width: 20px;
  height: 20px;
  background-color: transparent;
  border: 2px solid #000;
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.3s;
}

input[type="radio"]:checked + label::before {
  content: "";
  display: inline-block;
  width: 16px;
  height: 16px;
  background-color: #000;
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.3s;
}

input[type="radio"] + label::before {
  margin-right: 5px;
}