JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://modernizr.com/downloads/modernizr.js"></script>
<div data-feature='canvas'>Supporto al Canvas: <span></span></div>
<div data-feature='localstorage'>Supporto al Local Storage: <span></span></div>

CSS

.canvas div[data-feature='canvas'] span{
    color: green;
}
.no-canvas div[data-feature='canvas'] span{
    color: red;
}

.localstorage div[data-feature='localstorage'] span{
    color: green;
}
.no-localstorage div[data-feature='localstorage'] span{
    color: red;
}

JavaScript

document.querySelector('div[data-feature="canvas"] span').textContent = Modernizr.canvas ? 'supporato' : 'non supportato';
document.querySelector('div[data-feature="localstorage"] span').textContent = Modernizr.localstorage ? 'supporato' : 'non supportato';