JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://cdn.ractivejs.org/edge/ractive.js"></script>
<main></main>

<script id='template' type='text/ractive'>
    {{#if foo}}
        {{# steps[currentStep] }}
            argh
        {{/}}

    <!-- this is needed for some reason! -->
    {{/if}}
</script>

CSS

body {
    font-family: 'Helvetica Neue', arial, sans-serif;
    font-weight: 200;
    color: #353535;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 200;
}

.error {
    color: red;
}

JavaScript

var ractive = new Ractive({
    el: 'main',
    template: '#template',
    data: {
        currentStep: 0,
        steps: [{}, {}]
    }
});

ractive.set( 'foo', true );
ractive.set( 'foo', false );

try {
    ractive.set( 'currentStep', 1 );
} catch ( err ) {
    document.body.innerHTML = '<code class="error">' + err.message + '</code>';
    throw err;
}