Custom Styling Radio Buttons: The Modern Way (The Butterfield Way)

radio.css

:root {
  --radio-border-color: #8b8c89;
  --radio-checked-color: #274c77;
  --radio-hover-color: #a3cef1;
  --radio-disabled-bg-color: #d9d9d9;
}

input[type="radio"] {
  box-sizing: border-box;
  width: 20px;
  height: 20px;
  margin: 6px;
  padding: 0;
  border: 2px solid var(--radio-border-color);
  border-radius: 50%;
  appearance: none;
  background-color: transparent;
  outline: none;
  transition: outline 0.1s;
}

input[type="radio"]:not(:disabled):checked {
  border-color: var(--radio-checked-color);
  background-color: var(--radio-checked-color);
  background-clip: content-box;
  padding: 2px;
  background-image: radial-gradient(
    circle,
    var(--radio-checked-color) 0%,
    var(--radio-checked-color) 50%,
    transparent 60%,
    transparent 100%
  );
}

input[type="radio"]:disabled {
  background-color: var(--radio-disabled-bg-color);
}

input[type="radio"]:disabled:checked {
  background-image: radial-gradient(
    circle,
    var(--radio-border-color) 0%,
    var(--radio-border-color) 50%,
    transparent 50%,
    transparent 100%
  );
}

@media (hover: hover) {
  input[type="radio"]:not(:disabled):hover {
    background-color: var(--radio-hover-color);
    outline: 6px solid var(--radio-hover-color);
    transform: scale(1.05);
  }
}

input[type="radio"]:focus-visible {
  background-color: var(--radio-hover-color);
  outline: 6px solid var(--radio-hover-color);
  transform: scale(1.05);
}

@media (prefers-reduced-motion: reduce) {
  input[type="radio"] {
    transition: none;
  }

  input[type="radio"]:focus-visible {
    transform: scale(1);
  }
}

@media (prefers-reduced-motion: reduce) and (hover: hover) {
  input[type="radio"]:not(:disabled):hover {
    transform: scale(1);
  }
}

radio.scss

$radio-border-color: #8b8c89;
$radio-checked-color: #274c77;
$radio-hover-color: #a3cef1;
$radio-disabled-bg-color: #d9d9d9;

input[type="radio"] {
  box-sizing: border-box;
  width: 20px;
  height: 20px;
  margin: 6px;
  padding: 0;
  border: 2px solid $radio-border-color;
  border-radius: 50%;
  appearance: none;
  background-color: transparent;
  outline: none;
  transition: outline 0.1s;

  &:not(:disabled):checked {
    border-color: $radio-checked-color;
    background-color: $radio-checked-color;
    background-clip: content-box;
    padding: 2px;
    background-image: radial-gradient(
      circle,
      $radio-checked-color 0%,
      $radio-checked-color 50%,
      transparent 60%,
      transparent 100%
    );
  }

  &:disabled {
    background-color: $radio-disabled-bg-color;
  }

  &:disabled:checked {
    background-image: radial-gradient(
      circle,
      $radio-border-color 0%,
      $radio-border-color 50%,
      transparent 50%,
      transparent 100%
    );
  }

  &:focus-visible {
    background-color: $radio-hover-color;
    outline: 6px solid $radio-hover-color;
    transform: scale(1.05);
  }

  @media (hover: hover) {
    &:not(:disabled):hover {
      background-color: $radio-hover-color;
      outline: 6px solid $radio-hover-color;
      transform: scale(1.05);
    }
  }
  
  @media (prefers-reduced-motion: reduce) {
    transition: none;

    &:focus-visible {
      transform: scale(1);
    }
  }

  @media (prefers-reduced-motion: reduce) and (hover: hover) {
    &:not(:disabled):hover {
      transform: scale(1);
    }
  }
}