.opt-btn:disabled + .opt-label {
  position: relative;
  opacity: 0.45;
  cursor: not-allowed;
}

.opt-btn:disabled + .opt-label::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom right,
    transparent calc(50% - 0.5px),
    currentColor calc(50% - 0.5px),
    currentColor calc(50% + 0.5px),
    transparent calc(50% + 0.5px)
  );
  border-radius: inherit;
  pointer-events: none;
}