Live Validation Summary

<!-- Live Validation Summary — :has() reads three checkboxes, zero JS -->
<div class="nuda-co2-validation-summary">
  <input class="nuda-co2-validation-summary__input" type="checkbox" id="co2-vs-terms" checked />
  <label class="nuda-co2-validation-summary__row" for="co2-vs-terms">
    <span class="nuda-co2-validation-summary__box" aria-hidden="true"></span>
    <span class="nuda-co2-validation-summary__label">Accept terms of service</span>
  </label>

  <input class="nuda-co2-validation-summary__input" type="checkbox" id="co2-vs-privacy" checked />
  <label class="nuda-co2-validation-summary__row" for="co2-vs-privacy">
    <span class="nuda-co2-validation-summary__box" aria-hidden="true"></span>
    <span class="nuda-co2-validation-summary__label">Accept privacy policy</span>
  </label>

  <input class="nuda-co2-validation-summary__input" type="checkbox" id="co2-vs-age" />
  <label class="nuda-co2-validation-summary__row" for="co2-vs-age">
    <span class="nuda-co2-validation-summary__box" aria-hidden="true"></span>
    <span class="nuda-co2-validation-summary__label">Confirm you are 18+</span>
  </label>

  <div class="nuda-co2-validation-summary__summary" role="status" aria-live="polite">
    <span class="nuda-co2-validation-summary__summary-icon" aria-hidden="true"></span>
    <span>
      <span class="nuda-co2-validation-summary__txt-pending">Complete all items to continue</span>
      <span class="nuda-co2-validation-summary__txt-done">All requirements met — ready to continue</span>
    </span>
  </div>
</div>

.nuda-co2-validation-summary {
  --nuda-co2-vs-accent: #e4ff54;
  width: 100%;
  max-width: 280px;
  font-family: inherit;
}

.nuda-co2-validation-summary__input {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

.nuda-co2-validation-summary__row {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  cursor: pointer;
}

.nuda-co2-validation-summary__box {
  position: relative;
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  border-radius: 5px;
  border: 2px solid rgba(255,255,255,.22);
  background: transparent;
  transition: background .2s ease,border-color .2s ease;
}

.nuda-co2-validation-summary__box::after {
  content: "\2713";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 800;
  color: #09090b;
  opacity: 0;
  transform: scale(.5);
  transition: opacity .18s ease,transform .18s ease;
}

.nuda-co2-validation-summary__label {
  font-size: .76rem;
  color: #bbb;
}

.nuda-co2-validation-summary__input:checked+.nuda-co2-validation-summary__row .nuda-co2-validation-summary__box {
  background: var(--nuda-co2-vs-accent);
  border-color: var(--nuda-co2-vs-accent);
}

.nuda-co2-validation-summary__input:checked+.nuda-co2-validation-summary__row .nuda-co2-validation-summary__box::after {
  opacity: 1;
  transform: scale(1);
}

.nuda-co2-validation-summary__input:checked+.nuda-co2-validation-summary__row .nuda-co2-validation-summary__label {
  color: #eee;
}

.nuda-co2-validation-summary__input:focus-visible+.nuda-co2-validation-summary__row .nuda-co2-validation-summary__box {
  outline: 2px solid var(--nuda-co2-vs-accent);
  outline-offset: 2px;
}

.nuda-co2-validation-summary__summary {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: .6rem;
  padding: .55rem .7rem;
  font-size: .72rem;
  font-weight: 600;
  color: #e5b400;
  background: rgba(228,180,0,.08);
  border: 1px solid rgba(228,180,0,.25);
  border-radius: 9px;
  transition: background .2s ease,border-color .2s ease,color .2s ease;
}

.nuda-co2-validation-summary__summary-icon {
  flex-shrink: 0;
  width: 16px;
  height: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: currentColor;
}

.nuda-co2-validation-summary__summary-icon::after {
  content: "!";
  color: #09090b;
  font-size: 11px;
  font-weight: 800;
}

.nuda-co2-validation-summary__txt-done {
  display: none;
}

.nuda-co2-validation-summary:has(#co2-vs-terms:checked):has(#co2-vs-privacy:checked):has(#co2-vs-age:checked) .nuda-co2-validation-summary__summary {
  color: var(--nuda-co2-vs-accent);
  background: rgba(228,255,84,.1);
  border-color: rgba(228,255,84,.35);
  animation: _nuda-co2validationsummarypop .3s ease-out;
}

.nuda-co2-validation-summary:has(#co2-vs-terms:checked):has(#co2-vs-privacy:checked):has(#co2-vs-age:checked) .nuda-co2-validation-summary__summary-icon::after {
  content: "\2713";
}

.nuda-co2-validation-summary:has(#co2-vs-terms:checked):has(#co2-vs-privacy:checked):has(#co2-vs-age:checked) .nuda-co2-validation-summary__txt-pending {
  display: none;
}

.nuda-co2-validation-summary:has(#co2-vs-terms:checked):has(#co2-vs-privacy:checked):has(#co2-vs-age:checked) .nuda-co2-validation-summary__txt-done {
  display: inline;
}

@keyframes _nuda-co2validationsummarypop {
  from {
    transform: scale(.94);
    opacity: .4;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

@media (prefers-reduced-motion:reduce) {
  .nuda-co2-validation-summary__box,.nuda-co2-validation-summary__box::after,.nuda-co2-validation-summary__summary {
    transition: none;
  }
  .nuda-co2-validation-summary__summary {
    animation: none;
  }
}