JSFiddle - React, Tailwind, and code Playground

HTML

<main></main>

<script id='template' type='text/html'>
		{{#each this}}
    <p>twice <input type='number' value='{{num}}'> is {{@global.double(num)}}</p>
    {{/each}}
</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: #d00;
    font-family: monospace;
}

JavaScript

window.double = num => num * 2;

var ractive = new Ractive({
    el: 'main',
    template: '#template',
    data: [
    { num: 21 },
    { num: 21 },
    { num: 21 },
    { num: 21 }]
});