<label class="radikalwp-nv-burger"><input type="checkbox" /><span><//span><span><//span><span><//span><span><//span><//label>

.radikalwp-nv-burger {
  position: relative;
  display: inline-flex;
  flex-direction: column;
  gap: 5px;
  padding: 12px;
  background: #f1f5f9;
  border-radius: 12px;
  cursor: pointer;
}
.radikalwp-nv-burger input { display: none; }
.radikalwp-nv-burger span {
  width: 24px;
  height: 2.5px;
  background: #0f172a;
  border-radius: 2px;
  transition: all .3s ease;
}
.radikalwp-nv-burger input:checked ~ span:nth-child(2) { transform: translateY(7.5px) rotate(45deg); }
.radikalwp-nv-burger input:checked ~ span:nth-child(3) { opacity: 0; }
.radikalwp-nv-burger input:checked ~ span:nth-child(4) { transform: translateY(-7.5px) rotate(-45deg); }