ionic-framework/ionic/components/radio/radio.scss

// Radio
// --------------------------------------------------

$radio-padding:                   0 15px !default;


.radio .item-media {
  padding: $radio-padding;
}

.radio input {
  position: relative;
  left: -9999px;
}

.radio-on {
  display: none;
}

.radio-off {
  display: block;
}

.radio[aria-checked=true] {

  .radio-on {
    display: block;
  }

  .radio-off {
    display: none;
  }

}

.radio[aria-disabled=true] {
  pointer-events: none;
  opacity: 0.5;
  color: gray;

  .media-radio {
    color: inherit;
  }
}

// .radio .item-media,
// .radio .item-content {
//   pointer-events: none;
// }