.cb-blob {
  display: inline-flex; align-items: center;
  gap: 10px; cursor: pointer; user-select: none;
}
.cb-blob__input { display: none; }
.cb-blob__box {
  width: 28px; height: 28px; border-radius: 8px;
  border: 2px solid rgba(124,108,255,.3);
  display: flex; align-items: center;
  justify-content: center; overflow: hidden;
}
.cb-blob__shape {
  width: 18px; height: 18px;
  background: linear-gradient(135deg, #7c6cff, #ff6c8a);
  border-radius: 0;
  transform: scale(0) rotate(45deg);
  transition: transform .45s cubic-bezier(.34,1.56,.64,1),
              border-radius .45s ease;
}
.cb-blob__input:checked
  + .cb-blob__box .cb-blob__shape {
  transform: scale(1) rotate(0deg);
  border-radius: 60% 40% 30% 70% / 60% 30% 70% 40%;
}