Checkbox Bounce

<!-- Checkbox Bounce — checkbox with bouncy checkmark animation -->
<label class="nuda-checkbox">
  <input class="nuda-checkbox__input" type="checkbox" />
  <span class="nuda-checkbox__box">
    <svg class="nuda-checkbox__icon" viewBox="0 0 16 16" fill="none" aria-hidden="true">
      <path d="M3.5 8.5L6.5 11.5L12.5 4.5" stroke="currentColor"
            stroke-width="2" stroke-linecap="round" stroke-linejoin="round"/>
    </svg>
  </span>
  <span class="nuda-checkbox__label">Accept terms</span>
</label>

/* ── Checkbox Bounce ─────────────────────────────────────────
   Customize:
     --nuda-cb-size    : box size
     --nuda-cb-clr     : accent color
     --nuda-cb-radius  : corner radius
   ──────────────────────────────────────────────────────────── */
.nuda-checkbox {
  --nuda-cb-size: 22px;
  --nuda-cb-clr: #6366f1;
  --nuda-cb-radius: 6px;

  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  -webkit-user-select: none;
  user-select: none;
}

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

.nuda-checkbox__box {
  width: var(--nuda-cb-size);
  height: var(--nuda-cb-size);
  border: 2px solid #d1d5db;
  border-radius: var(--nuda-cb-radius);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s, border-color 0.2s;
}

.nuda-checkbox__icon {
  width: 14px;
  height: 14px;
  color: #fff;
  transform: scale(0);
  transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Checked state */
.nuda-checkbox__input:checked + .nuda-checkbox__box {
  background: var(--nuda-cb-clr);
  border-color: var(--nuda-cb-clr);
}

.nuda-checkbox__input:checked + .nuda-checkbox__box .nuda-checkbox__icon {
  transform: scale(1);
}

/* Focus ring */
.nuda-checkbox__input:focus-visible + .nuda-checkbox__box {
  outline: 2px solid var(--nuda-cb-clr);
  outline-offset: 2px;
}

.nuda-checkbox__label {
  font-size: 0.95rem;
}

/* ── Accessibility ──────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  .nuda-checkbox__icon,
  .nuda-checkbox__box {
    transition: none;
  }
}