gistfile1.txt

function jsonp(url) {
    var script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = url;
    document.head.appendChild(script);
}

function ff(fonts) {
    var style = document.createElement('style');
    var str = '@import url(' + location.protocol + '//fonts.googleapis.com/css?family=' + fonts.items.map(function (item) {
        return item.family.replace(/ /g, '+')
    }).join('|') + ');';
    style.textContent = str;
    document.head.appendChild(style);
    toggleFonts(fonts);
}

function toggleFonts(fonts) {
    var font = fonts.items[Math.floor(Math.random() * fonts.items.length)].family;
    document.body.style.fontFamily = font;
    console.log('changing fonts to', font);
    setTimeout(toggleFonts.bind(null, fonts), Math.random()*30000+10000);
}

jsonp("https://www.googleapis.com/webfonts/v1/webfonts?key=AIzaSyDBzzPRqWl2eU_pBMDr_8mo1TbJgDkgst4&sort=trending&callback=ff");