mdb-ui-kit/less/_togglebutton.less

.togglebutton {
  vertical-align: middle;
  &, label, input, .toggle {
    user-select: none;
  }
  label {
    font-weight: 400;
    cursor: pointer;
    // Hide original checkbox
    input[type=checkbox]:first-of-type {
      opacity: 0;
      width: 0;
      height:0;
    }
    // Switch bg off and disabled
    .toggle,
    input[type=checkbox][disabled]:first-of-type + .toggle {
      content: "";
      display: inline-block;
      width: 30px;
      height: 15px;
      background-color: rgba(80, 80, 80, 0.7);
      border-radius: 15px;
      margin-right: 10px;
      transition: background 0.3s ease;
      vertical-align: middle;
    }
    // Handle off
    .toggle:after {
      content: "";
      display: inline-block;
      width: 20px;
      height: 20px;
      background-color: #F1F1F1;
      border-radius: 20px;
      position: relative;
      box-shadow: 0 1px 3px 1px rgba(0,0,0,0.4);
      left: -5px;
      top: -2px;
      transition: left 0.3s ease, background 0.3s ease, box-shadow 0.1s ease;
    }
    // Handle disabled
    input[type=checkbox][disabled]:first-of-type + .toggle:after,
    input[type=checkbox][disabled]:checked:first-of-type + .toggle:after{
      background-color: #BDBDBD;
    }
    // Ripple off and disabled
    input[type=checkbox]:first-of-type ~ .toggle:active:after,
    input[type=checkbox][disabled]:first-of-type ~ .toggle:active:after {
      box-shadow: 0 1px 3px 1px rgba(0,0,0,0.4), 0 0 0 15px rgba(0, 0, 0, 0.1);
    }
    input[type=checkbox]:first-of-type:checked + .toggle:after {
      left: 15px;
    }
  }

  // Switch bg on
  .generic-variations(~" label input[type=checkbox]:first-of-type:checked + .toggle", @primary, {
    background-color: fade(@material-color, 50%);
  });
  // Handle on
  .variations(~" label input[type=checkbox]:first-of-type:checked + .toggle:after", background-color, @primary);
  // Ripple on
  .generic-variations(~" label input[type=checkbox]:first-of-type:checked ~ .toggle:active:after", @primary, {
    box-shadow: 0 1px 3px 1px rgba(0,0,0,0.4), 0 0 0 15px fade(@material-color, 10%);
  });
}