body {

  font-family: sans-serif;

}

.demo {

  margin-left: 80px;

}

radio-button {

  position: relative;

  display: block;

  font-size: 18px;

  padding: 2px 0;

}

radio-button:focus {

  outline: none;

}

radio-button::before {

  content: "";

  display: block;

  width: 10px;

  height: 10px;

  border: 1px solid black;

  position: absolute;

  left: -18px;

  top: 7px;

  border-radius: 50%;

}

radio-button:focus::before {

  box-shadow: 0 0 3px 3px #83beff;

}

radio-button[aria-checked="true"]::before {

  content: "";

  display: block;

  width: 10px;

  height: 10px;

  background: red;

  position: absolute;

  left: -18px;

  top: 7px;

  border-radius: 50%;

}

​