checkboxstyle

.checkbox {
  position: relative;
  width: 16px;
  height: 16px;
  cursor: pointer;
}

.checkbox input {
  margin: 0px;
  background: none;
}

.checkbox-inner {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1;
  width: inherit;
  height: inherit;
  border: 2px solid grey;
  background-color: #fff;
  border-radius: 2px;
}

.checkbox-inner:hover {
  border: 2px solid yellowgreen;
}

.checkbox-checked .checkbox-inner {
  background-color: yellowgreen;
  border: 2px solid yellowgreen;
}

.checkbox-checked .checkbox-inner::after {
    position: absolute;
    display: table;
    border: 2px solid #fff;
    border-top: 0;
    border-left: 0;
    transform: rotate(45deg) scale(1) translate(-50%,-50%);
    opacity: 1;
    top: 50%;
    left: 21%;
    display: table;
    width: 5px;
    height: 9px;
    content: '';
}