<div class="main">
        Question 1
        <div class="inputG">
            <input class="input" type=radio name='one'>
            <input class="input" type=radio name='one'>
            <input class="input" type=radio name='one'>
        </div>
        <div class="wrap">
            <button class="button">Next</button>
        </div>
</div>

.button {
  pointer-events: none;
  opacity: 0.5;
  user-select: none;
}

.inputG:has(.input:checked) ~ .wrap .button {
  pointer-events: unset;
  opacity: 1;
}