flaskdashboard/app/base/static/assets/scss/black-dashboard/custom/_checkboxes-radio.scss

.form-check{
 margin-top: .5rem;
 padding-left: 0;
}

.form-check .form-check-label{
  display: inline-block;
  position: relative;
  cursor: pointer;
  padding-left: 25px;
  line-height: 18px;
  margin-bottom: 0;
  -webkit-transition: color 0.3s linear;
  -moz-transition: color 0.3s linear;
  -o-transition: color 0.3s linear;
  -ms-transition: color 0.3s linear;
  transition: color 0.3s linear;
}
.radio .form-check-sign{
    padding-left: 28px;
}

.form-check-radio.form-check-inline .form-check-label {
  padding-left: 5px;
  margin-right: 10px;
}

.form-check .form-check-sign::before,
.form-check .form-check-sign::after{
  content: " ";
  display: inline-block;
  position: absolute;
  width: 17px;
  height: 17px;
  left: 0;
  cursor: pointer;
  border-radius: 3px;
  top: 0;
  border: 1px solid darken($dark-gray,10%);
  -webkit-transition: opacity 0.3s linear;
  -moz-transition: opacity 0.3s linear;
  -o-transition: opacity 0.3s linear;
  -ms-transition: opacity 0.3s linear;
  transition: opacity 0.3s linear;
}

.form-check input[type="checkbox"]:checked + .form-check-sign::before,
.form-check input[type="checkbox"]:checked + .form-check-sign::before{
  border: none;
  background-color: $primary;
}

 .form-check .form-check-sign::after{
  font-family: 'nucleo';
  content: "\ea1b";
  top: 0px;
  text-align: center;
  font-size: 14px;
  opacity: 0;
  color: $white;
  font-weight: $font-weight-bold;
  border: 0;
  background-color: inherit;
}

.form-check.disabled .form-check-label,
.form-check.disabled .form-check-label {
    color: $dark-gray;
    opacity: .5;
    cursor: not-allowed;
}

.form-check input[type="checkbox"],
.radio input[type="radio"]{
  opacity: 0;
  position: absolute;
  visibility: hidden;
}
.form-check input[type="checkbox"]:checked + .form-check-sign::after{
  opacity: 1;
  font-size: 10px;
  margin-top: 0;
}


.form-check input[type="checkbox"]+ .form-check-sign::after{
  opacity: 0;
  font-size: 10px;
  margin-top: 0;
}

.form-control input[type="checkbox"]:disabled + .form-check-sign::before,
.checkbox input[type="checkbox"]:disabled + .form-check-sign::after{
    cursor: not-allowed;
}

.form-check input[type="checkbox"]:disabled + .form-check-sign,
.form-check input[type="radio"]:disabled + .form-check-sign{
    pointer-events: none;
}

.form-check-radio .form-check-label{
  padding-top: 3px;
}
.form-check-radio .form-check-sign::before,
.form-check-radio .form-check-sign::after{
  content: " ";
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 1px solid darken($dark-gray,10%);
  display: inline-block;
  position: absolute;
  left: 0px;
  top: 3px;
  padding: 1px;
  -webkit-transition: opacity 0.3s linear;
  -moz-transition: opacity 0.3s linear;
  -o-transition: opacity 0.3s linear;
  -ms-transition: opacity 0.3s linear;
  transition: opacity 0.3s linear;
}

.form-check-radio input[type="radio"] + .form-check-sign:after,
.form-check-radio input[type="radio"] {
    opacity: 0;
}
.form-check-radio input[type="radio"]:checked + .form-check-sign::after {
    width: 6px;
    height: 6px;
    background-color: $primary;
    border-color: $primary;
    top: 9px;
    left: 6px;
    opacity: 1;
}

.form-check-radio input[type="radio"]:checked + .form-check-sign::before {
  border-color: $primary;
}


.form-check-radio input[type="radio"]:checked + .form-check-sign::after{
    opacity: 1;
}

.form-check-radio input[type="radio"]:disabled + .form-check-sign {
  color: $dark-gray;
}

.form-check-radio input[type="radio"]:disabled + .form-check-sign::before,
.form-check-radio input[type="radio"]:disabled + .form-check-sign::after {
  color: $dark-gray;
}