.input--checkbox {
  appearance: none;
  width: 1rem;
  height: 1rem;
  border: 1px solid;
  border-radius: 100%;
  padding: 0.125rem;
  flex-shrink: 0;
}

.input--checkbox::after {
  content: '';
  display: block;
  width: 100%;
  height: 100%;
  background: transparent;
  border-radius: 100%;
}

.input--checkbox:checked::after {
  background: currentColor;
}