.checkbox {
  position: relative;
  display: inline-block;
}

.hidden-input[type='checkbox'] {
  display: none;
  box-sizing: border-box;
}

.custom-input {
  cursor: pointer;
  position: relative;
  padding: 0;
  display: inline;
  display: -ms-flexbox;
  display: flex;
}

.custom-input:before {
  transition: 0.2s ease-out;
  content: '';
  width: 16px;
  height: 16px;
  display: inline-block;
  background: #fff;
  border: 1px solid #111;
  border-radius: 2px;
  vertical-align: middle;
}

.custom-input:after {
  transition: 0.2s ease-out;
  content: '';
  position: absolute;
  width: 5px;
  height: 8px;
  top: 3px;
  left: 6px;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

input[type='checkbox'][disabled] ~ .custom-input {
  opacity: 0.4;
  cursor: not-allowed;
}

input[type='checkbox']:checked ~ .custom-input:before {
  background: #3b7b8f;
  border: 1px solid #3b7b8f;
}

input[type='checkbox'] ~ .custom-input:after {
  visibility: hidden;
}

input[type='checkbox']:checked ~ .custom-input:after {
  visibility: visible;
  visibility: initial;
}