JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.min.js"></script>
<input type=checkbox class="ins" ng-model=show ng-class='{open:show}'><b>Show</b>

CSS

.ins {
        -moz-appearance:none;
        -o-appearance:none;
        -webkit-appearance: none;
        width: 14px;
        height: 14px;
    }
    .ins:after {

        content: ' + ';
        font-weight: 800;

    }
    .ins.open[type=checkbox]:after {

        content:" - ";
        font-weight: 800;
    }

JavaScript

var myApp = angular.module('myApp', []);