style.css

body{
  margin: 50px;
}

.checkbox-switch__input, .checkbox-switch__input:checked {
  display: none;
}

.checkbox-switch__input + .checkbox-switch__label:before {
  content: "";
}

.checkbox-switch__input + .checkbox-switch__label:after {
  display: block;
  height: 40px;
  width: 40px;
  position: absolute;
  content: "";
  margin-top: -1px;
}
.checkbox-switch__label {
  text-align: center;
}
.checkbox-switch__input + .checkbox-switch__label {
  position: absolute;
  width: 90px;
  height: 40px;
  background-color: #dddddd;
  border-radius: 60px;
}

.checkbox-switch__input + .checkbox-switch__label > .checkbox-switch__label--on {
  opacity: 0;
  line-height: 40px;
  position: absolute;
  margin-left: 10px;
}

.checkbox-switch__input + .checkbox-switch__label > .checkbox-switch__label--off {
  opacity: 1;
  float: right;
  line-height: 40px;
  margin-right: 10px;
}

.checkbox-switch__input + label:after {
  width: 34px;
  margin-top: -35px;
  background-color: white;
  border-radius: 100%;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
  transition: margin 0.4s;
}

.checkbox-switch__input:checked + .checkbox-switch__label {
  background-color: green;
}

.checkbox-switch__input:checked + .checkbox-switch__label > .checkbox-switch__label--on {
  opacity: 1;
}

.checkbox-switch__input:checked + .checkbox-switch__label > .checkbox-switch__label--off {
  opacity: 0;
}

input.checkbox-switch__input:checked + label:after {
  margin-left: 50px;
}