checkbox style issue css

I have some code for the check box items, im try to make this tick like a close icon, i cant do it correctly , how can i make it this type, look image example check box

please anyone help me, Thanks

.round {
  position: relative;
}

  .round label {
  background-color: #fff;
  border: 1px solid #81bea0;
  border-radius: 50%;
  cursor: pointer;
  height: 28px;
  left: 0;
  position: absolute;
  top: 0;
  width: 28px;
}

  .round label:after {
  border: 2px solid #fff;
  border-top: none;
  border-right: none;
  content: "";
  height: 6px;
  left: 7px;
  opacity: 0;
  position: absolute;
  top: 8px;
  transform: rotate(-45deg);
  width: 12px;
}

 .round input[type="checkbox"] {
  visibility: hidden;
}

  .round input[type="checkbox"]:checked + label {
  background-color: #54a985;
  border-color: #66bb6a;
}

 .round input[type="checkbox"]:checked + label:after {
  opacity: 1;
}

<span class="chk-box01"><div class="round">
     <input type="checkbox" id="checkbox" />
     <label for="checkbox"></label>
     </div></span>