<fieldset class="crb-ink">
  <legend class="crb-sr">Theme</legend>
  <label><input type="radio" name="crb-ink" /><span></span>Light</label>
  <label><input type="radio" name="crb-ink" checked /><span></span>Dark</label>
  <label><input type="radio" name="crb-ink" /><span></span>Auto</label>
</fieldset>

.crb-ink { display: flex; flex-direction: column; gap: 10px; border: 0; padding: 0; }
.crb-ink label {
  display: flex; align-items: center; gap: 10px;
  font: 500 13px/1 system-ui, sans-serif; color: #cbd5e1; cursor: pointer;
}
.crb-ink input { appearance: none; -webkit-appearance: none; position: absolute; opacity: 0; }
.crb-ink span {
  width: 18px; height: 18px; border-radius: 50%;
  border: 2px solid #444461; background: transparent;
  position: relative; overflow: hidden;
  transition: border-color 0.25s;
}
.crb-ink span::before {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(180deg, #06b6d4, #0ea5e9);
  transform: translateY(-100%);
  transition: transform 0.5s cubic-bezier(0.65,0,0.35,1);
}
.crb-ink input:checked + span { border-color: #06b6d4; }
.crb-ink input:checked + span::before { transform: translateY(0); }

.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;
}