input[type="radio"] {
opacity: 0.24;
}

<div class="some-parent">
<button type="button">Some button</button>
</div>

.some-parent:focus-within {
outline: 2px solid purple;
outline-offset: 5px;
}

tbody:hover tr:not(:hover) {
opacity: 0.24;
}

button {
font-size: 16px;
padding: .5em;
}

.link {
  color: #222;
}

.link::before {
  background-color: #222;
}

.link {
color: #222;
}

.link::before {
background-color: currentColor;
}