<fieldset class="crb-stack">
  <legend class="crb-sr">Notifications</legend>
  <input type="radio" name="crb-stack" id="crb-stack-1" checked />
  <label for="crb-stack-1"><strong>All</strong><em>Every update</em></label>
  <input type="radio" name="crb-stack" id="crb-stack-2" />
  <label for="crb-stack-2"><strong>Important</strong><em>Critical only</em></label>
  <input type="radio" name="crb-stack" id="crb-stack-3" />
  <label for="crb-stack-3"><strong>Off</strong><em>Silent mode</em></label>
  <span class="crb-stack-rail"></span>
</fieldset>

.crb-stack {
  display: flex; flex-direction: column;
  position: relative; padding-left: 12px;
  border: 0; border-left: 2px solid rgba(255,255,255,0.06);
}
.crb-stack input { appearance: none; -webkit-appearance: none; position: absolute; opacity: 0; }
.crb-stack label {
  display: flex; flex-direction: column; gap: 2px;
  padding: 8px 10px; border-radius: 6px;
  cursor: pointer; transition: color 0.25s, background 0.25s;
}
.crb-stack label strong {
  font: 600 13px/1 system-ui, sans-serif; color: #cbd5e1;
}
.crb-stack label em {
  font: 500 11px/1 system-ui, sans-serif; color: #b8b6d4; font-style: normal;
}
.crb-stack input:checked + label strong { color: #fff; }
.crb-stack input:checked + label { background: rgba(124,108,255,0.06); }
.crb-stack-rail {
  position: absolute; left: -2px; top: 0;
  width: 2px; height: 33.333%;
  background: linear-gradient(180deg, #7c6cff, #a78bfa);
  border-radius: 2px;
  transition: transform 0.4s cubic-bezier(0.65,0,0.35,1);
}
#crb-stack-2:checked ~ .crb-stack-rail { transform: translateY(100%); }
#crb-stack-3:checked ~ .crb-stack-rail { transform: translateY(200%); }

.crb-sr {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}